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Ruiz-Mateos Serrano R, Aguzin A, Mitoudi-Vagourdi E, Tao X, Naegele TE, Jin AT, Lopez-Larrea N, Picchio ML, Vinicio Alban-Paccha M, Minari RJ, Mecerreyes D, Dominguez-Alfaro A, Malliaras GG. 3D printed PEDOT:PSS-based conducting and patternable eutectogel electrodes for machine learning on textiles. Biomaterials 2024; 310:122624. [PMID: 38805956 DOI: 10.1016/j.biomaterials.2024.122624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/26/2024] [Accepted: 05/19/2024] [Indexed: 05/30/2024]
Abstract
The proliferation of medical wearables necessitates the development of novel electrodes for cutaneous electrophysiology. In this work, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is combined with a deep eutectic solvent (DES) and polyethylene glycol diacrylate (PEGDA) to develop printable and biocompatible electrodes for long-term cutaneous electrophysiology recordings. The impact of printing parameters on the conducting properties, morphological characteristics, mechanical stability and biocompatibility of the material were investigated. The optimised eutectogel formulations were fabricated in four different patterns -flat, pyramidal, striped and wavy- to explore the influence of electrode geometry on skin conformability and mechanical contact. These electrodes were employed for impedance and forearm EMG measurements. Furthermore, arrays of twenty electrodes were embedded into a textile and used to generate body surface potential maps (BSPMs) of the forearm, where different finger movements were recorded and analysed. Finally, BSPMs for three different letters (B, I, O) in sign-language were recorded and used to train a logistic regressor classifier able to reliably identify each letter. This novel cutaneous electrode fabrication approach offers new opportunities for long-term electrophysiological recordings, online sign-language translation and brain-machine interfaces.
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Affiliation(s)
- Ruben Ruiz-Mateos Serrano
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK
| | - Ana Aguzin
- Group of Polymers and Polymerization Reactors, INTEC, National University of the Litoral - CONICET, Güemes 3450, Santa Fe, 3000, Argentina
| | - Eleni Mitoudi-Vagourdi
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK
| | - Xudong Tao
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK
| | - Tobias E Naegele
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK
| | - Amy T Jin
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK
| | - Naroa Lopez-Larrea
- POLYMAT, University of the Basque Country UPV/EHU, Avenida Tolosa 72, Donostia-San Sebastián, Gipuzkoa, 20018, Spain
| | - Matías L Picchio
- POLYMAT, University of the Basque Country UPV/EHU, Avenida Tolosa 72, Donostia-San Sebastián, Gipuzkoa, 20018, Spain; Group of Polymers and Polymerization Reactors, INTEC, National University of the Litoral - CONICET, Güemes 3450, Santa Fe, 3000, Argentina
| | - Marco Vinicio Alban-Paccha
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK; Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge, UK
| | - Roque J Minari
- Group of Polymers and Polymerization Reactors, INTEC, National University of the Litoral - CONICET, Güemes 3450, Santa Fe, 3000, Argentina
| | - David Mecerreyes
- POLYMAT, University of the Basque Country UPV/EHU, Avenida Tolosa 72, Donostia-San Sebastián, Gipuzkoa, 20018, Spain; IKERBASQUE, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Antonio Dominguez-Alfaro
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
| | - George G Malliaras
- Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Ave, Cambridge, CB3 0FA, UK.
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2
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Zhao J, Feng J, Jiang Y, Wang Z, Zhang J, Mei S, Yang G, Gu Z, Tan C, Qin Y, Li Z. Skin-Integrated Electrodes Based on Room-Temperature Curable, Highly Conductive Silver/Polydimethylsiloxane Composites. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309470. [PMID: 38148306 DOI: 10.1002/smll.202309470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Indexed: 12/28/2023]
Abstract
The quality of electrophysiological (EP) signals heavily relies on the electrode's contact with the skin. However, motion or exposure to water can easily destabilize this connection. In contrast to traditional methods of attaching electrodes to the skin surface, this study introduces a skin-integration strategy inspired by the skin's intergrown structure. A highly conductive and room-temperature curable composite composed of silver microflakes and polydimethylsiloxane (Ag/PDMS) is applied to the skin. Before curing, the PDMS oil partially diffuse into the stratum corneum (SC) layer of the skin. Upon curing, the composite solidifies into an electrode that seamlessly integrated with the skin, resembling a natural extension. This skin-integration strategy offers several advantages. It minimizes motion artifacts resulting from relative electrode-skin displacement, significantly reduces interface impedance (67% of commercial Ag/AgCl gel electrodes at 100 Hz) and withstands water flushes due to its hydrophobic nature. These advantages pave the way for promising advancements in EP signal recording, particularly during motion and underwater conditions.
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Affiliation(s)
- Jun Zhao
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
| | - Jiuqing Feng
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Yizhou Jiang
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Zekai Wang
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
| | - Jialong Zhang
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Shuxing Mei
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
| | - Guoqing Yang
- School of Microelectronics and State Key Laboratory of Integrated Chip and Systems, Fudan University, Shanghai, 200433, China
| | - Zongquan Gu
- School of Microelectronics and State Key Laboratory of Integrated Chip and Systems, Fudan University, Shanghai, 200433, China
| | - Cehui Tan
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Yajie Qin
- School of Information Science and Technology, Fudan University, Shanghai, 200433, China
| | - Zhuo Li
- Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
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3
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Lan T, Tian H, Chen X, Li X, Wang C, Wang D, Li S, Liu G, Zhu X, Shao J. Treefrog-Inspired Flexible Electrode with High Permeability, Stable Adhesion, and Robust Durability. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2404761. [PMID: 38796773 DOI: 10.1002/adma.202404761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 05/20/2024] [Indexed: 05/28/2024]
Abstract
Long-term continuous monitoring (LTCM) of physiological electrical signals is an effective means for detecting several cardiovascular diseases. However, the integrated challenges of stable adhesion, low impedance, and robust durability under different skin conditions significantly hinder the application of flexible electrodes in LTCM. This paper proposes a structured electrode inspired by the treefrog web, comprising dispersed pillars at the bottom and asymmetric cone holes at the top. Attachment structures with a dispersed pillar improve the contact stability (adhesion increases 2.79/13.16 times in dry/wet conditions compared to an electrode without structure). Improved permeable duct structure provides high permeability (12 times compared to cotton). Due to high adhesion and permeability, the electrode's durability is 40 times larger than commercial Ag/AgCl electrodes. The treefrog web-like electrode has great advantages in permeability, adhesion, and durability, resulting in prospects for application in physiological electrical signal detection and a new design idea for LTCM wearable dry electrodes.
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Affiliation(s)
- Tianxiang Lan
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Hongmiao Tian
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Xiaoliang Chen
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, 99 YanXiang Road, West 5th building, Xi'an, Shaanxi, 710054, China
| | - Xiangming Li
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, 99 YanXiang Road, West 5th building, Xi'an, Shaanxi, 710054, China
| | - Chunhui Wang
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Duorui Wang
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Sheng Li
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Gangqiang Liu
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Xinkai Zhu
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Jinyou Shao
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
- Frontier Institute of Science and Technology (FIST), Xi'an Jiaotong University, 99 YanXiang Road, West 5th building, Xi'an, Shaanxi, 710054, China
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4
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Cuttaz EA, Bailey ZK, Chapman CAR, Goding JA, Green RA. Polymer Bioelectronics: A Solution for Both Stimulating and Recording Electrodes. Adv Healthc Mater 2024:e2304447. [PMID: 38775757 DOI: 10.1002/adhm.202304447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/31/2024] [Indexed: 06/01/2024]
Abstract
The advent of closed-loop bionics has created a demand for electrode materials that are ideal for both stimulating and recording applications. The growing complexity and diminishing size of implantable devices for neural interfaces have moved beyond what can be achieved with conventional metallic electrode materials. Polymeric electrode materials are a recent development based on polymer composites of organic conductors such as conductive polymers. These materials present exciting new opportunities in the design and fabrication of next-generation electrode arrays which can overcome the electrochemical and mechanical limitations of conventional electrode materials. This review will examine the recent developments in polymeric electrode materials, their application as stimulating and recording electrodes in bionic devices, and their impact on the development of soft, conformal, and high-density neural interfaces.
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Affiliation(s)
- Estelle A Cuttaz
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Zachary K Bailey
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Christopher A R Chapman
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
- School of Engineering and Materials Science, Queen Mary University of London, London, E1 4NS, UK
| | - Josef A Goding
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
| | - Rylie A Green
- Department of Bioengineering, Imperial College London, London, SW7 2BX, UK
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5
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Park B, Jeong C, Ok J, Kim TI. Materials and Structural Designs toward Motion Artifact-Free Bioelectronics. Chem Rev 2024; 124:6148-6197. [PMID: 38690686 DOI: 10.1021/acs.chemrev.3c00374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Bioelectronics encompassing electronic components and circuits for accessing human information play a vital role in real-time and continuous monitoring of biophysiological signals of electrophysiology, mechanical physiology, and electrochemical physiology. However, mechanical noise, particularly motion artifacts, poses a significant challenge in accurately detecting and analyzing target signals. While software-based "postprocessing" methods and signal filtering techniques have been widely employed, challenges such as signal distortion, major requirement of accurate models for classification, power consumption, and data delay inevitably persist. This review presents an overview of noise reduction strategies in bioelectronics, focusing on reducing motion artifacts and improving the signal-to-noise ratio through hardware-based approaches such as "preprocessing". One of the main stress-avoiding strategies is reducing elastic mechanical energies applied to bioelectronics to prevent stress-induced motion artifacts. Various approaches including strain-compliance, strain-resistance, and stress-damping techniques using unique materials and structures have been explored. Future research should optimize materials and structure designs, establish stable processes and measurement methods, and develop techniques for selectively separating and processing overlapping noises. Ultimately, these advancements will contribute to the development of more reliable and effective bioelectronics for healthcare monitoring and diagnostics.
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Affiliation(s)
- Byeonghak Park
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Chanho Jeong
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Jehyung Ok
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
| | - Tae-Il Kim
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Republic of Korea
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6
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Takagi T, Tomita N, Sato S, Yamamoto M, Takamatsu S, Itoh T. Wearable EMG Measurement Device Using Polyurethane Foam for Motion Artifact Suppression. SENSORS (BASEL, SWITZERLAND) 2024; 24:2985. [PMID: 38793840 PMCID: PMC11124951 DOI: 10.3390/s24102985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/30/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024]
Abstract
We propose the use of a specially designed polyurethane foam with a plateau region in its mechanical characteristics-where stress remains nearly constant during deformation-between the electromyography (EMG) electrode and clothing to suppress motion artifacts in EMG measurement. Wearable EMG devices are receiving attention for monitoring muscle weakening due to aging. However, daily EMG measurement has been challenging due to motion artifacts caused by changes in the contact pressure between the bioelectrode and the skin. Therefore, this study aims to measure EMG signals in daily movement environments by controlling the contact pressure using polyurethane foam between the bioelectrode on the clothing and the skin. Through mechanical calculations and finite element method simulations of the polyurethane foam's effect, we clarified that the characteristics of the polyurethane foam significantly influence contact pressure control and that the contact pressure is adjustable through the polyurethane foam thickness. The optimization of the design successfully controlled the contact pressure between the bioelectrode and skin from 1.0 kPa to 2.0 kPa, effectively suppressing the motion artifact in EMG measurement.
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Affiliation(s)
- Takuma Takagi
- Department of Precision Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8654, Japan; (N.T.); (S.S.); (S.T.); (T.I.)
| | | | | | - Michitaka Yamamoto
- Department of Precision Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8654, Japan; (N.T.); (S.S.); (S.T.); (T.I.)
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7
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Zhuo S, Zhang A, Tessier A, Williams C, Kabiri Ameri S. Solvent-Free and Cost-Efficient Fabrication of a High-Performance Nanocomposite Sensor for Recording of Electrophysiological Signals. BIOSENSORS 2024; 14:188. [PMID: 38667181 PMCID: PMC11048393 DOI: 10.3390/bios14040188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 03/28/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024]
Abstract
Carbon nanotube (CNT)-based nanocomposites have found applications in making sensors for various types of physiological sensing. However, the sensors' fabrication process is usually complex, multistep, and requires longtime mixing and hazardous solvents that can be harmful to the environment. Here, we report a flexible dry silver (Ag)/CNT/polydimethylsiloxane (PDMS) nanocomposite-based sensor made by a solvent-free, low-temperature, time-effective, and simple approach for electrophysiological recording. By mechanical compression and thermal treatment of Ag/CNT, a connected conductive network of the fillers was formed, after which the PDMS was added as a polymer matrix. The CNTs make a continuous network for electrons transport, endowing the nanocomposite with high electrical conductivity, mechanical strength, and durability. This process is solvent-free and does not require a high temperature or complex mixing procedure. The sensor shows high flexibility and good conductivity. High-quality electroencephalography (EEG) and electrooculography (EOG) were performed using fabricated dry sensors. Our results show that the Ag/CNT/PDMS sensor has comparable skin-sensor interface impedance with commercial Ag/AgCl-coated dry electrodes, better performance for noninvasive electrophysiological signal recording, and a higher signal-to-noise ratio (SNR) even after 8 months of storage. The SNR of electrophysiological signal recording was measured to be 26.83 dB for our developed sensors versus 25.23 dB for commercial Ag/AgCl-coated dry electrodes. Our process of compress-heating the functional fillers provides a universal approach to fabricate various types of nanocomposites with different nanofillers and desired electrical and mechanical properties.
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Affiliation(s)
- Shuyun Zhuo
- Department of Electrical and Computer Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Anan Zhang
- Department of Electrical and Computer Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Alexandre Tessier
- Department of Electrical and Computer Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Chris Williams
- Department of Electrical and Computer Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Shideh Kabiri Ameri
- Department of Electrical and Computer Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
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8
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Wang Z, Ding Y, Yuan W, Chen H, Chen W, Chen C. Active Claw-Shaped Dry Electrodes for EEG Measurement in Hair Areas. Bioengineering (Basel) 2024; 11:276. [PMID: 38534550 DOI: 10.3390/bioengineering11030276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/01/2024] [Accepted: 03/07/2024] [Indexed: 03/28/2024] Open
Abstract
EEG, which can provide brain alteration information via recording the electrical activity of neurons in the cerebral cortex, has been widely used in neurophysiology. However, conventional wet electrodes in EEG monitoring typically suffer from inherent limitations, including the requirement of skin pretreatment, the risk of superficial skin infections, and signal performance deterioration that may occur over time due to the air drying of the conductive gel. Although the emergence of dry electrodes has overcome these shortcomings, their electrode-skin contact impedance is significantly high and unstable, especially in hair-covered areas. To address the above problems, an active claw-shaped dry electrode is designed, moving from electrode morphological design, slurry preparation, and coating to active electrode circuit design. The active claw-shaped dry electrode, which consists of a claw-shaped electrode and active electrode circuit, is dedicated to offering a flexible solution for elevating electrode fittings on the scalp in hair-covered areas, reducing electrode-skin contact impedance and thus improving the quality of the acquired EEG signal. The performance of the proposed electrodes was verified by impedance, active electrode circuit, eyes open-closed, steady-state visually evoked potential (SSVEP), and anti-interference tests, based on EEG signal acquisition. Experimental results show that the proposed claw-shaped electrodes (without active circuit) can offer a better fit between the scalp and electrodes, with a low electrode-skin contact impedance (18.62 KΩ@1 Hz in the hairless region and 122.15 KΩ@1 Hz in the hair-covered region). In addition, with the active circuit, the signal-to-noise ratio (SNR) of the acquiring EEG signal was improved and power frequency interference was restrained, therefore, the proposed electrodes can yield an EEG signal quality comparable to wet electrodes.
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Affiliation(s)
- Zaihao Wang
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Yuhao Ding
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wei Yuan
- Center for Intelligent Medical Equipment and Devices, Institute for Innovative Medical Devices, School of Biomedical Engineering, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215123, China
| | - Hongyu Chen
- Center for Intelligent Medical Electronics, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wei Chen
- School of Biomedical Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Chen Chen
- Human Phenome Institute, Fudan University, Shanghai 201203, China
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9
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Kim H, Lee J, Heo U, Jayashankar DK, Agno KC, Kim Y, Kim CY, Oh Y, Byun SH, Choi B, Jeong H, Yeo WH, Li Z, Park S, Xiao J, Kim J, Jeong JW. Skin preparation-free, stretchable microneedle adhesive patches for reliable electrophysiological sensing and exoskeleton robot control. SCIENCE ADVANCES 2024; 10:eadk5260. [PMID: 38232166 DOI: 10.1126/sciadv.adk5260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/18/2023] [Indexed: 01/19/2024]
Abstract
High-fidelity and comfortable recording of electrophysiological (EP) signals with on-the-fly setup is essential for health care and human-machine interfaces (HMIs). Microneedle electrodes allow direct access to the epidermis and eliminate time-consuming skin preparation. However, existing microneedle electrodes lack elasticity and reliability required for robust skin interfacing, thereby making long-term, high-quality EP sensing challenging during body movement. Here, we introduce a stretchable microneedle adhesive patch (SNAP) providing excellent skin penetrability and a robust electromechanical skin interface for prolonged and reliable EP monitoring under varying skin conditions. Results demonstrate that the SNAP can substantially reduce skin contact impedance under skin contamination and enhance wearing comfort during motion, outperforming gel and flexible microneedle electrodes. Our wireless SNAP demonstration for exoskeleton robot control shows its potential for highly reliable HMIs, even under time-dynamic skin conditions. We envision that the SNAP will open new opportunities for wearable EP sensing and its real-world applications in HMIs.
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Affiliation(s)
- Heesoo Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Juhyun Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ung Heo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | | | - Karen-Christian Agno
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Yeji Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Choong Yeon Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Youngjun Oh
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sang-Hyuk Byun
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Bohyung Choi
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hwayeong Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Woon-Hong Yeo
- IEN Center for Wearable Intelligent Systems and Healthcare at the Institute for Electronics and Nanotechnology, Georgia Institute of Technology, Atlanta, GA 30332, USA
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, GA 30332, USA
- Parker H. Petit Institute for Bioengineering and Biosciences, Institute for Materials, Neural Engineering Center, Institute for Robotics and Intelligent Machines, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Zhuo Li
- Department of Material Science, Fudan University, Shanghai 200433, China
| | - Seongjun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jianliang Xiao
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Jung Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jae-Woong Jeong
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
- KAIST Institute for Health Science and Technology, Daejeon 34141, Republic of Korea
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10
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Tian F, Zhu L, Shi Q, Wang R, Zhang L, Dong Q, Qian K, Zhao Q, Hu B. The Three-Lead EEG Sensor: Introducing an EEG-Assisted Depression Diagnosis System Based on Ant Lion Optimization. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2023; 17:1305-1318. [PMID: 37402182 DOI: 10.1109/tbcas.2023.3292237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
For depression diagnosis, traditional methods such as interviews and clinical scales have been widely leveraged in the past few decades, but they are subjective, time-consuming, and labor-consuming. With the development of affective computing and Artificial Intelligence (AI) technologies, Electroencephalogram (EEG)-based depression detection methods have emerged. However, previous research has virtually neglected practical application scenarios, as most studies have focused on analyzing and modeling EEG data. Furthermore, EEG data is typically obtained from specialized devices that are large, complex to operate, and poorly ubiquitous. To address these challenges, a wearable three-lead EEG sensor with flexible electrodes was developed to obtain prefrontal-lobe EEG data. Experimental measurements show that the EEG sensor achieves promising performance (background noise of no more than 0.91 μVpp, Signal-to-Noise Ratio (SNR) of 26--48 dB, and electrode-skin contact impedance of less than 1 K Ω). In addition, EEG data from 70 depressed patients and 108 healthy controls were collected using the EEG sensor, and the linear and nonlinear features were extracted. The features were then weighted and selected using the Ant Lion Optimization (ALO) algorithm to improve classification performance. The experimental results show that the k-NN classifier achieves a classification accuracy of 90.70%, specificity of 96.53%, and sensitivity of 81.79%, indicating the promising potential of the three-lead EEG sensor combined with the ALO algorithm and the k-NN classifier for EEG-assisted depression diagnosis.
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11
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Rho S, Kim H, Lim D, Jeong W. Fabrication and Evaluation of Embroidery-Based Electrode for EMG Smart Wear Using Moss Stitch Technique. SENSORS (BASEL, SWITZERLAND) 2023; 23:9012. [PMID: 37960710 PMCID: PMC10648407 DOI: 10.3390/s23219012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023]
Abstract
Wearable 2.0 research has been conducted on the manufacture of smart fitness wear that collects bio-signals through the wearing of a textile-based electrode. Among them, the electromyography (EMG) suit measures the electrical signals generated by the muscles to check their activity, such as contraction and relaxation. General gel-type electrodes have been reported to cause skin diseases due to an uncomfortable feel and skin irritation when attached to the skin for a long time. Dry electrodes of various materials are being developed to solve this problem. Previous research has reported EMG detectio performance and conducted economic comparisons according to the size and shape of the embroidery electrode. On the other hand, these embroidery electrodes still have foreign body sensations. In this study, a moss sEMG electrode was produced with various shapes (W3 and WF) and loop lengths (1-5 mm). The optimized conditions of the embroidery-based electrodes were derived and analyzed with the tactile comfort factors and sensing performances. As the loop length of the electrode increased, MIU and Qmax increased, but the SMD decreased due to the free movement of the threads constituting the loop. Impedance and sEMG detection performance showed different trends depending on the electrode type.
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Affiliation(s)
- Soohyeon Rho
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea; (S.R.); (H.K.); (D.L.)
- Department of Nano Science and Technology, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyelim Kim
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea; (S.R.); (H.K.); (D.L.)
| | - Daeyoung Lim
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea; (S.R.); (H.K.); (D.L.)
| | - Wonyoung Jeong
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Republic of Korea; (S.R.); (H.K.); (D.L.)
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12
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Wang J, Wang T, Liu H, Wang K, Moses K, Feng Z, Li P, Huang W. Flexible Electrodes for Brain-Computer Interface System. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211012. [PMID: 37143288 DOI: 10.1002/adma.202211012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/27/2023] [Indexed: 05/06/2023]
Abstract
Brain-computer interface (BCI) has been the subject of extensive research recently. Governments and companies have substantially invested in relevant research and applications. The restoration of communication and motor function, the treatment of psychological disorders, gaming, and other daily and therapeutic applications all benefit from BCI. The electrodes hold the key to the essential, fundamental BCI precondition of electrical brain activity detection and delivery. However, the traditional rigid electrodes are limited due to their mismatch in Young's modulus, potential damages to the human body, and a decline in signal quality with time. These factors make the development of flexible electrodes vital and urgent. Flexible electrodes made of soft materials have grown in popularity in recent years as an alternative to conventional rigid electrodes because they offer greater conformance, the potential for higher signal-to-noise ratio (SNR) signals, and a wider range of applications. Therefore, the latest classifications and future developmental directions of fabricating these flexible electrodes are explored in this paper to further encourage the speedy advent of flexible electrodes for BCI. In summary, the perspectives and future outlook for this developing discipline are provided.
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Affiliation(s)
- Junjie Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Tengjiao Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Haoyan Liu
- Department of Computer Science & Computer Engineering (CSCE), University of Arkansas, Fayetteville, AR, 72701, USA
| | - Kun Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Kumi Moses
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Zhuoya Feng
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Peng Li
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics (FSCFE), Xi'an Institute of Flexible Electronics (IFE) & Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, Shaanxi, 710072, P. R. China
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13
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Gao K, Wu N, Ji B, Liu J. A Film Electrode upon Nanoarchitectonics of Bacterial Cellulose and Conductive Fabric for Forehead Electroencephalogram Measurement. SENSORS (BASEL, SWITZERLAND) 2023; 23:7887. [PMID: 37765945 PMCID: PMC10535237 DOI: 10.3390/s23187887] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023]
Abstract
In this paper, we present a soft and moisturizing film electrode based on bacterial cellulose and Ag/AgCl conductive cloth as a potential replacement for gel electrode patches in electroencephalogram (EEG) recording. The electrode materials are entirely flexible, and the bacterial cellulose membrane facilitates convenient adherence to the skin. EEG signals are transmitted from the skin to the bacterial cellulose first and then transferred to the Ag/AgCl conductive cloth connected to the amplifier. The water in the bacterial cellulose moisturizes the skin continuously, reducing the contact impedance to less than 10 kΩ, which is lower than commercial gel electrode patches. The contact impedance and equivalent circuits indicate that the bacterial cellulose electrode effectively reduces skin impedance. Moreover, the bacterial cellulose electrode exhibits lower noise than the gel electrode patch. The bacterial cellulose electrode has demonstrated success in collecting α rhythms. When recording EEG signals, the bacterial cellulose electrode and gel electrode have an average coherence of 0.86, indicating that they have similar performance across different EEG bands. Compared with current mainstream conductive rubber dry electrodes, gel electrodes, and conductive cloth electrodes, the bacterial cellulose electrode has obvious advantages in terms of contact impedance. The bacterial cellulose electrode does not cause skin discomfort after long-term recording, making it more suitable for applications with strict requirements for skin affinity than gel electrode patches.
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Affiliation(s)
- Kunpeng Gao
- The School of Information Science and Technology, Donghua University, Shanghai 200051, China;
| | - Nailong Wu
- The School of Information Science and Technology, Donghua University, Shanghai 200051, China;
| | - Bowen Ji
- The Unmanned System Research Institute, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Jingquan Liu
- Department of Micro/Nano-Electronics, Shanghai Jiao Tong University, Shanghai 200240, China
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14
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Zhang A, Shyam AB, Cunningham AM, Williams C, Brissenden A, Bartley A, Amsden B, Docoslis A, Kontopoulou M, Ameri SK. Adhesive Wearable Sensors for Electroencephalography from Hairy Scalp. Adv Healthc Mater 2023; 12:e2300142. [PMID: 37165724 DOI: 10.1002/adhm.202300142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/23/2023] [Indexed: 05/12/2023]
Abstract
Electroencephalography has garnered interest for applications in mobile healthcare, human-machine interfaces, and Internet of Things. Conventional electroencephalography relies on wet and dry electrodes. Despite favorable interface impedance of wet electrodes and skin, the application of a large amount of gel at their interface with skin limits the electroencephalography spatial resolution, increases the risk of shorting between electrodes, and makes them unsuited for long-term mobile recording. In contrast, dry electrodes are better suited for long-term recordings but susceptible to motion artifacts. In addition, both wet and dry electrodes are non-adhesive to the hairy scalp and mechanical support, or chemical adhesives are used to hold them in place. Herein, a conical microstructure array (CMSA) based sensor made of carbon nanotube-polydimethylsiloxane composite is reported. The CMSA sensor is fabricated using the innovative, cost-effective, and scalable method of viscosity-controlled dip-pull process. The sensor adheres to the hairy scalp by generating negative pressure in its conical microstructures when it is pressed against scalp. Aided by the application of a trace amount of gel, CMSA sensor establishes good electrical contact with the skin, enabling its applications in mobile electroencephalography over extended periods. Notably, the signal quality of CMSA sensors is comparable to that of medical-grade wet gel electrodes.
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Affiliation(s)
- Anan Zhang
- Department of Electrical and Computer Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | | | | | - Christopher Williams
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Amanda Brissenden
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Alex Bartley
- Department of Electrical and Computer Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Brian Amsden
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Aristides Docoslis
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Marianna Kontopoulou
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Shideh Kabiri Ameri
- Department of Electrical and Computer Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
- Centre for Neuroscience Studies (CNS), Queen's University, Kingston, Ontario, K7L 3N6, Canada
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15
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Lee M, Kim J, Khine MT, Kim S, Gandla S. Facile Transfer of Spray-Coated Ultrathin AgNWs Composite onto the Skin for Electrophysiological Sensors. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2467. [PMID: 37686975 PMCID: PMC10489915 DOI: 10.3390/nano13172467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/26/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
Disposable wearable sensors that ultrathin and conformable to the skin are of significant interest as affordable and easy-to-use devices for short-term recording. This study presents a facile and low-cost method for transferring spray-coated silver nanowire (AgNW) composite films onto human skin using glossy paper (GP) and liquid bandages (LB). Due to the moderately hydrophobic and rough surface of the GP, the ultrathin AgNWs composite film (~200 nm) was easily transferred onto human skin. The AgNW composite films conformally attached to the skin when applied with a LB, resulting in the stable and continuous recording of wearable electrophysiological signals, including electromyogram (EMG), electrocardiogram (ECG), and electrooculogram (EOG). The volatile LB, deposited on the skin via spray coating, promoted rapid adhesion of the transferred AgNW composite films, ensuring stability to the AgNWs in external environments. The AgNWs composite supported with the LB film exhibited high water vapor breathability (~28 gm-2h-1), which can avoid the accumulation of sweat at the skin-sensor interface. This approach facilitates the creation of rapid, low-cost, and disposable tattoo-like sensors that are practical for extended use.
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Affiliation(s)
| | | | | | - Sunkook Kim
- Multifunctional Nano Bio Electronics Lab, Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea; (M.L.); (J.K.); (M.T.K.)
| | - Srinivas Gandla
- Multifunctional Nano Bio Electronics Lab, Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea; (M.L.); (J.K.); (M.T.K.)
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16
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Zahed MA, Kim DK, Jeong SH, Selim Reza M, Sharifuzzaman M, Pradhan GB, Song H, Asaduzzaman M, Park JY. Microfluidic-Integrated Multimodal Wearable Hybrid Patch for Wireless and Continuous Physiological Monitoring. ACS Sens 2023; 8:2960-2974. [PMID: 37498214 DOI: 10.1021/acssensors.3c00148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Despite extensive advances in wearable monitoring systems, most designs focus on the detection of physical parameters or metabolites and do not consider the integration of microfluidic channels, miniaturization, and multimodality. In this study, a combination of multimodal (biochemical and electrophysiological) biosensing and microfluidic channel-integrated patch-based wireless systems is designed and fabricated using flexible materials for improved wearability, ease of operation, and real-time and continuous monitoring. The reduced graphene oxide-based microfluidic channel-integrated glucose biosensor exhibits a good sensitivity of 19.97 (44.56 without fluidic channels) μA mM-1 cm-2 within physiological levels (10 μM-0.4 mM) with good long-term and bending stability. All the sensors in the patch are initially validated using sauna gown sweat-based on-body and real-time tests with five separate individuals who perspired three times each. Multimodal glucose and electrocardiogram (ECG) sensing, along with their real-time adjustment based on sweat pH and temperature fluctuations, optimize sensing accuracy. Laser-burned hierarchical MXene-polyvinylidene fluoride-based conductive carbon nanofiber-based dry ECG electrodes exhibit low skin contact impedance (40.5 kΩ cm2) and high-quality electrophysiological signals (signal-to-noise ratios = 23.4-32.8 dB). The developed system is utilized to accurately and wirelessly monitor the sweat glucose and ECG of a human subject engaged in physical exercise in real time.
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Affiliation(s)
- Md Abu Zahed
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Dong Kyun Kim
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Seong Hoon Jeong
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Md Selim Reza
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Md Sharifuzzaman
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Gagan Bahadur Pradhan
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Hyesu Song
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Md Asaduzzaman
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
| | - Jae Yeong Park
- Department of Electronic Engineering, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- Human IoT Focused Research Center, Kwangwoon University, 447-1, Seoul 139-701, Republic of Korea
- SnE Solution Co. Ltd, 447-1, Seoul 139-701, Republic of Korea
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17
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Petrossian G, Kateb P, Miquet-Westphal F, Cicoira F. Advances in Electrode Materials for Scalp, Forehead, and Ear EEG: A Mini-Review. ACS APPLIED BIO MATERIALS 2023; 6:3019-3032. [PMID: 37493408 DOI: 10.1021/acsabm.3c00322] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Electroencephalogram (EEG) records the electrical activity of neurons in the cerebral cortex and is used extensively to diagnose, treat, and monitor psychiatric and neurological conditions. Reliable contact between the skin and the electrodes is essential for achieving consistency and for obtaining electroencephalographic information. There has been an increasing demand for effective equipment and electrodes to overcome the time-consuming and cumbersome application of traditional systems. Recently, ear-centered EEG has met with growing interest since it can provide good signal quality due to the proximity of the ear to the brain. In addition, it can facilitate mobile and unobtrusive usage due to its smaller size and ease of use, since it can be used without interfering with the patient's daily activities. The purpose of this mini-review is to first introduce the broad range of electrodes used in conventional (scalp) EEG and subsequently discuss the state-of-the-art literature about around- and in-the-ear EEG.
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Affiliation(s)
- Gayaneh Petrossian
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Pierre Kateb
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | | | - Fabio Cicoira
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
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18
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Karamikamkar S, Yalcintas EP, Haghniaz R, de Barros NR, Mecwan M, Nasiri R, Davoodi E, Nasrollahi F, Erdem A, Kang H, Lee J, Zhu Y, Ahadian S, Jucaud V, Maleki H, Dokmeci MR, Kim H, Khademhosseini A. Aerogel-Based Biomaterials for Biomedical Applications: From Fabrication Methods to Disease-Targeting Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2204681. [PMID: 37217831 PMCID: PMC10427407 DOI: 10.1002/advs.202204681] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Indexed: 05/24/2023]
Abstract
Aerogel-based biomaterials are increasingly being considered for biomedical applications due to their unique properties such as high porosity, hierarchical porous network, and large specific pore surface area. Depending on the pore size of the aerogel, biological effects such as cell adhesion, fluid absorption, oxygen permeability, and metabolite exchange can be altered. Based on the diverse potential of aerogels in biomedical applications, this paper provides a comprehensive review of fabrication processes including sol-gel, aging, drying, and self-assembly along with the materials that can be used to form aerogels. In addition to the technology utilizing aerogel itself, it also provides insight into the applicability of aerogel based on additive manufacturing technology. To this end, how microfluidic-based technologies and 3D printing can be combined with aerogel-based materials for biomedical applications is discussed. Furthermore, previously reported examples of aerogels for regenerative medicine and biomedical applications are thoroughly reviewed. A wide range of applications with aerogels including wound healing, drug delivery, tissue engineering, and diagnostics are demonstrated. Finally, the prospects for aerogel-based biomedical applications are presented. The understanding of the fabrication, modification, and applicability of aerogels through this study is expected to shed light on the biomedical utilization of aerogels.
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Affiliation(s)
| | | | - Reihaneh Haghniaz
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | | | - Marvin Mecwan
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | - Rohollah Nasiri
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | - Elham Davoodi
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
- Department of Mechanical and Mechatronics EngineeringUniversity of WaterlooWaterlooONN2L 3G1Canada
| | - Fatemeh Nasrollahi
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
- Department of BioengineeringUniversity of California‐Los Angeles (UCLA)Los AngelesCA90095USA
| | - Ahmet Erdem
- Department of Biomedical EngineeringKocaeli UniversityUmuttepe CampusKocaeli41001Turkey
| | - Heemin Kang
- Department of Materials Science and EngineeringKorea UniversitySeoul02841Republic of Korea
| | - Junmin Lee
- Department of Materials Science and EngineeringPohang University of Science and Technology (POSTECH)Pohang37673Republic of Korea
| | - Yangzhi Zhu
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | - Samad Ahadian
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | - Vadim Jucaud
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
| | - Hajar Maleki
- Institute of Inorganic ChemistryDepartment of ChemistryUniversity of CologneGreinstraße 650939CologneGermany
- Center for Molecular Medicine CologneCMMC Research CenterRobert‐Koch‐Str. 2150931CologneGermany
| | | | - Han‐Jun Kim
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
- College of PharmacyKorea UniversitySejong30019Republic of Korea
| | - Ali Khademhosseini
- Terasaki Institute for Biomedical Innovation (TIBI)Los AngelesCA90024USA
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19
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Jin JE, Kim S, Yu H, Lee KN, Do YR, Lee SM. Soft, adhesive and conductive composite for electroencephalogram signal quality improvement. Biomed Eng Lett 2023; 13:495-504. [PMID: 37519875 PMCID: PMC10382389 DOI: 10.1007/s13534-023-00279-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 08/01/2023] Open
Abstract
Since electroencephalogram (EEG) is a very small electrical signal from the brain, it is very vulnerable to external noise or motion artifact, making it difficult to measure. Therefore, despite the excellent convenience of dry electrodes, wet electrodes have been used. To solve this problem, self-adhesive and conductive composites using carbon nanotubes (CNTs) in adhesive polydimethylsiloxane (aPDMS), which can have the advantages of both dry and wet electrodes, have been developed by mixing them uniformly with methyl group-terminated PDMS. The CNT/aPDMS composite has a low Young's modulus, penetrates the skin well, has a high contact area, and excellent adhesion and conductivity, so the signal quality is enhanced. As a result of the EEG measurement test, although it was a dry electrode, results comparable to those of a wet electrode were obtained in terms of impedance and motion noise. It also shows excellent biocompatibility in a human fibroblast cell test and a week-long skin reaction test, so it can measure EEG with high signal quality for a long period of time.
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Affiliation(s)
- Jeong E Jin
- School of Electrical Engineering, Kookmin University, Seoul, 02707 South Korea
| | - Seohyeon Kim
- School of Electrical Engineering, Kookmin University, Seoul, 02707 South Korea
| | - Hyeji Yu
- School of Electrical Engineering, Kookmin University, Seoul, 02707 South Korea
| | - Keyong Nam Lee
- Department of Chemistry, Kookmin University, Seoul, 02707 South Korea
| | - Young Rag Do
- Department of Chemistry, Kookmin University, Seoul, 02707 South Korea
| | - Seung Min Lee
- School of Electrical Engineering, Kookmin University, Seoul, 02707 South Korea
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20
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Tian Q, Zhao H, Wang X, Jiang Y, Zhu M, Yelemulati H, Xie R, Li Q, Su R, Cao Z, Jiang N, Huang J, Li G, Chen S, Chen X, Liu Z. Hairy-Skin-Adaptive Viscoelastic Dry Electrodes for Long-Term Electrophysiological Monitoring. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2211236. [PMID: 37072159 DOI: 10.1002/adma.202211236] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/31/2023] [Indexed: 06/11/2023]
Abstract
Long-term epidermal electrophysiological (EP) monitoring is crucial for disease diagnosis and human-machine synergy. The human skin is covered with hair that grows at an average rate of 0.3 mm per day. This impedes a stable contact between the skin and dry epidermal electrodes, resulting in motion artifacts during ultralong-term EP monitoring. Therefore, accurate and high-quality EP signal detection remains challenging. To address this issue, a new solution-the hairy-skin-adaptive viscoelastic dry electrode (VDE) is reported. This innovative technology is capable of bypassing hair and filling into the skin wrinkles, leading to long-lasting and stable interface impedance. The VDE maintains a stable interface impedance for a remarkable period of 48 days and 100 cycles. The VDE is highly effective in shielding against hair disturbances in electrocardiography (ECG) monitoring, even during intense chest expansion, and in electromyography (EMG) monitoring during large strain. Furthermore, the VDE is easily attachable to the skull without requiring any electroencephalogram (EEG) cap or bandage, making it an ideal solution for EEG monitoring. This work represents a substantial breakthrough in the field of EP monitoring, providing a solution for the previously challenging issue of monitoring human EP signals on hairy skin.
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Affiliation(s)
- Qiong Tian
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Hang Zhao
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xin Wang
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Ying Jiang
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Mingxing Zhu
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Huoerhute Yelemulati
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ruijie Xie
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Qingsong Li
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Rui Su
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Zhengshuai Cao
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Naifu Jiang
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Jianping Huang
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Guanglin Li
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Shixiong Chen
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Xiaodong Chen
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Zhiyuan Liu
- Neural Engineering Centre, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
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21
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Mao P, Li H, Yu Z. A Review of Skin-Wearable Sensors for Non-Invasive Health Monitoring Applications. SENSORS (BASEL, SWITZERLAND) 2023; 23:3673. [PMID: 37050733 PMCID: PMC10099362 DOI: 10.3390/s23073673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 06/19/2023]
Abstract
The early detection of fatal diseases is crucial for medical diagnostics and treatment, both of which benefit the individual and society. Portable devices, such as thermometers and blood pressure monitors, and large instruments, such as computed tomography (CT) and X-ray scanners, have already been implemented to collect health-related information. However, collecting health information using conventional medical equipment at home or in a hospital can be inefficient and can potentially affect the timeliness of treatment. Therefore, on-time vital signal collection via healthcare monitoring has received increasing attention. As the largest organ of the human body, skin delivers significant signals reflecting our health condition; thus, receiving vital signals directly from the skin offers the opportunity for accessible and versatile non-invasive monitoring. In particular, emerging flexible and stretchable electronics demonstrate the capability of skin-like devices for on-time and continuous long-term health monitoring. Compared to traditional electronic devices, this type of device has better mechanical properties, such as skin conformal attachment, and maintains compatible detectability. This review divides the health information that can be obtained from skin using the sensor aspect's input energy forms into five categories: thermoelectrical signals, neural electrical signals, photoelectrical signals, electrochemical signals, and mechanical pressure signals. We then summarize current skin-wearable health monitoring devices and provide outlooks on future development.
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Affiliation(s)
- Pengsu Mao
- Department of Industrial and Manufacturing Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32310, USA
- High-Performance Materials Institute, Florida State University, Tallahassee, FL 32310, USA
| | - Haoran Li
- Department of Industrial and Manufacturing Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32310, USA
- High-Performance Materials Institute, Florida State University, Tallahassee, FL 32310, USA
| | - Zhibin Yu
- Department of Industrial and Manufacturing Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL 32310, USA
- High-Performance Materials Institute, Florida State University, Tallahassee, FL 32310, USA
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22
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Merhi Y, Betancur PF, Ripolles TS, Suetta C, Brage-Andersen MR, Hansen SK, Frydenlund A, Nygaard JV, Mikkelsen PH, Boix PP, Agarwala S. Printed dry electrode for neuromuscular electrical stimulation (NMES) for e-textile. NANOSCALE 2023; 15:5337-5344. [PMID: 36815314 DOI: 10.1039/d2nr06008f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Muscle atrophy is a well-known consequence of immobilization and critical illness, leading to prolonged rehabilitation and increased mortality. In this study, we develop a solution to preserve muscle mass using customized biocompatible neuromuscular electrical stimulation (NMES) device. Commercially available NMES solutions with gel-based electrodes often lead to skin irritation. We demonstrate the printing of conducting electrodes on a compressive stocking textile that can be used for more than seven days without observing any inflammation. This solution consists of a dry and biocompatible electrode directly integrated into the textile with good mechanical compatibility with skin (Young's modulus of 0.39 MPa). The surface roughness of the underlying substrate plays a significant role in obtaining good print quality. Electrochemical Impedance Spectroscopy (EIS) analysis showed that the printed electrode showed better performance than the commercial ones based on a matched interfacial performance and improved series resistance. Furthermore, we investigated our NMES solution in a hospital setting to evaluate its effectiveness on muscle atrophy, with promising results.
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Affiliation(s)
- Youssif Merhi
- Department of Electrical and Computer Engineering, Aarhus University, Denmark.
| | - Pablo F Betancur
- Universidad de Valencia, Instituto de Ciencia de Materiales, Spain
| | | | - Charlotte Suetta
- Department of Geriatric and Palliative Medicine, Copenhagen University Hospital-Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Morten R Brage-Andersen
- Department of Geriatric and Palliative Medicine, Copenhagen University Hospital-Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Sofie K Hansen
- Department of Geriatric and Palliative Medicine, Copenhagen University Hospital-Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Anders Frydenlund
- Department of Geriatric and Palliative Medicine, Copenhagen University Hospital-Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Jens Vinge Nygaard
- Department of Biological and Chemical Engineering, Aarhus University, Denmark
| | - Peter H Mikkelsen
- Department of Electrical and Computer Engineering, Aarhus University, Denmark.
| | - Pablo P Boix
- Universidad de Valencia, Instituto de Ciencia de Materiales, Spain
| | - Shweta Agarwala
- Department of Electrical and Computer Engineering, Aarhus University, Denmark.
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23
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Huang H, Shen J, Wan S, Han L, Dou G, Sun L. Wet-Adhesive Multifunctional Hydrogel with Anti-swelling and a Skin-Seamless Interface for Underwater Electrophysiological Monitoring and Communication. ACS APPLIED MATERIALS & INTERFACES 2023; 15:11549-11562. [PMID: 36847327 DOI: 10.1021/acsami.2c21595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A stable and seamless adhesion between the human skin and the hydrogel-based electronic skin is necessary for accurate sensing and human health monitoring in aquatic environments. Despite achieving significant progress in this field, it remains a great challenge to design skin-interfaced conductive hydrogels with high electrical conductivity, stablility, and seamless underwater adhesion to skin. Herein, a skin-inspired conductive multifunctional hydrogel is proposed, which has a wet-adhesive/hydrophilic and a non-adhesive/hydrophobic bilayer structure. The hydrogel shows high stretchability (∼2400%) and an ultra-low modulus (4.5 kPa), which facilitate the conformal and seamless attachment of the hydrogel to the skin with reduced motion artifacts. Owing to synergistic physical and chemical interactions, this hydrogel can achieve reliable underwater adhesion and display remarkable underwater adhesion strength (388.1 kPa) to porcine skin. In addition, MXene has been employed to obtain high electrical conductivity, create a route for stable electron transport, and reinforce mechanical properties. The hydrogel also possesses self-healing ability, a low swelling ratio (∼3.8%), biocompatibility, and specific adhesion to biological tissues in water. Facilitated with these advantages, the hydrogel-based electrodes achieve reliable electrophysiological signal detection in both air and wet conditions and demonstrate a higher signal-to-noise ratio (28.3 dB) than that of commercial Ag/AgCl gel electrodes (18.5 dB). Also, the hydrogel can be utilized as a strain sensor with high sensitivity for underwater communication. This multifunctional hydrogel improves the stability of the skin-hydrogel interface in aquatic environments and is expected to be promising for the next-generation bio-integrated electronics.
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Affiliation(s)
- Haizhou Huang
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, P. R. China
| | - Jiaxin Shen
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, P. R. China
| | - Shu Wan
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Key Disciplines Laboratory of Novel Micro-Nano Devices and System Technology, School of Optoelectronics Engineering, Chongqing University, Chongqing 400044, China
| | - Longxiang Han
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, P. R. China
| | - Guangbin Dou
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, P. R. China
| | - Litao Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System, Southeast University, Nanjing 210096, P. R. China
- Center for Advanced Materials and Manufacture, Joint Research Institute of Southeast University and Monash University, Suzhou 215123, P. R. China
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24
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Rêgo AS, Filipe L, Dias RA, Alves FS, Queiroz J, Ainla A, Arruda LM, Fangueiro R, Bouçanova M, Bernardes RA, de Sousa LB, Santos-Costa P, Apóstolo JA, Parreira P, Salgueiro-Oliveira A. End-User Assessment of an Innovative Clothing-Based Sensor Developed for Pressure Injury Prevention: A Mixed-Method Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20054039. [PMID: 36901051 PMCID: PMC10001934 DOI: 10.3390/ijerph20054039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/19/2023] [Accepted: 02/22/2023] [Indexed: 06/01/2023]
Abstract
This study aimed to evaluate a clothing prototype that incorporates sensors for the evaluation of pressure, temperature, and humidity for the prevention of pressure injuries, namely regarding physical and comfort requirements. A mixed-method approach was used with concurrent quantitative and qualitative data triangulation. A structured questionnaire was applied before a focus group of experts to evaluate the sensor prototypes. Data were analyzed using descriptive and inferential statistics and the discourse of the collective subject, followed by method integration and meta-inferences. Nine nurses, experts in this topic, aged 32.66 ± 6.28 years and with a time of profession of 10.88 ± 6.19 years, participated in the study. Prototype A presented low evaluation in stiffness (1.56 ± 1.01) and roughness (2.11 ± 1.17). Prototype B showed smaller values in dimension (2.77 ± 0.83) and stiffness (3.00 ± 1.22). Embroidery was assessed as inadequate in terms of stiffness (1.88 ± 1.05) and roughness (2.44 ± 1.01). The results from the questionnaires and focus groups' show low adequacy as to stiffness, roughness, and comfort. The participants highlighted the need for improvements regarding stiffness and comfort, suggesting new proposals for the development of sensors for clothing. The main conclusions are that Prototype A presented the lowest average scores relative to rigidity (1.56 ± 1.01), considered inadequate. This dimension of Prototype B was evaluated as slightly adequate (2.77 ± 0.83). The rigidity (1.88 ± 1.05) of Prototype A + B + embroidery was evaluated as inadequate. The prototype revealed clothing sensors with low adequacy regarding the physical requirements, such as stiffness or roughness. Improvements are needed regarding the stiffness and roughness for the safety and comfort characteristics of the device evaluated.
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Affiliation(s)
- Anderson S. Rêgo
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Luísa Filipe
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Rosana A. Dias
- International Iberian Laboratory of Nanotechnology (INL), 4715-330 Braga, Portugal
| | - Filipe S. Alves
- International Iberian Laboratory of Nanotechnology (INL), 4715-330 Braga, Portugal
| | - José Queiroz
- International Iberian Laboratory of Nanotechnology (INL), 4715-330 Braga, Portugal
| | - Alar Ainla
- International Iberian Laboratory of Nanotechnology (INL), 4715-330 Braga, Portugal
| | - Luísa M. Arruda
- Fibrenamics, Institute of Innovation on Fibre-Based Materials and Composites, University of Minho, 4800-058 Guimaraes, Portugal
- Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimaraes, Portugal
| | - Raul Fangueiro
- Fibrenamics, Institute of Innovation on Fibre-Based Materials and Composites, University of Minho, 4800-058 Guimaraes, Portugal
- Centre for Textile Science and Technology (2C2T), University of Minho, 4800-058 Guimaraes, Portugal
| | - Maria Bouçanova
- Impetus Portugal-Têxteis Sa (IMPETUS), 4740-696 Barcelos, Portugal
| | - Rafael A. Bernardes
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Liliana B. de Sousa
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Paulo Santos-Costa
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - João A. Apóstolo
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Pedro Parreira
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
| | - Anabela Salgueiro-Oliveira
- Health Sciences Research Unit: Nursing (UICISA: E), Nursing School of Coimbra (ESEnfC), 3000-232 Coimbra, Portugal
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25
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Marmo AC, Grunlan MA. Biomedical Silicones: Leveraging Additive Strategies to Propel Modern Utility. ACS Macro Lett 2023; 12:172-182. [PMID: 36669481 PMCID: PMC10848296 DOI: 10.1021/acsmacrolett.2c00701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/18/2023] [Indexed: 01/21/2023]
Abstract
Silicones have a long history of use in biomedical devices, with unique properties stemming from the siloxane (Si-O-Si) backbone that feature a high degree of flexibility and chemical stability. However, surface, rheological, mechanical, and electrical properties of silicones can limit their utility. Successful modification of silicones to address these limitations could lead to superior and new biomedical devices. Toward improving such properties, recent additive strategies have been leveraged to modify biomedical silicones and are highlighted herein.
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Affiliation(s)
- Alec C. Marmo
- Department
of Materials Science and Engineering Texas
A&M University, College
Station, Texas 77843-3003, United States
| | - Melissa A. Grunlan
- Department
of Biomedical Engineering, Department of Materials Science and Engineering,
Department of Chemistry Texas A&M University, College Station, Texas 77843-3003, United
States
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26
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Sun F, Jiang H, Wang H, Zhong Y, Xu Y, Xing Y, Yu M, Feng LW, Tang Z, Liu J, Sun H, Wang H, Wang G, Zhu M. Soft Fiber Electronics Based on Semiconducting Polymer. Chem Rev 2023; 123:4693-4763. [PMID: 36753731 DOI: 10.1021/acs.chemrev.2c00720] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Fibers, originating from nature and mastered by human, have woven their way throughout the entire history of human civilization. Recent developments in semiconducting polymer materials have further endowed fibers and textiles with various electronic functions, which are attractive in applications such as information interfacing, personalized medicine, and clean energy. Owing to their ability to be easily integrated into daily life, soft fiber electronics based on semiconducting polymers have gained popularity recently for wearable and implantable applications. Herein, we present a review of the previous and current progress in semiconducting polymer-based fiber electronics, particularly focusing on smart-wearable and implantable areas. First, we provide a brief overview of semiconducting polymers from the viewpoint of materials based on the basic concepts and functionality requirements of different devices. Then we analyze the existing applications and associated devices such as information interfaces, healthcare and medicine, and energy conversion and storage. The working principle and performance of semiconducting polymer-based fiber devices are summarized. Furthermore, we focus on the fabrication techniques of fiber devices. Based on the continuous fabrication of one-dimensional fiber and yarn, we introduce two- and three-dimensional fabric fabricating methods. Finally, we review challenges and relevant perspectives and potential solutions to address the related problems.
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Affiliation(s)
- Fengqiang Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Hao Jiang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Haoyu Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yueheng Zhong
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yiman Xu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yi Xing
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Muhuo Yu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Shanghai Key Laboratory of Lightweight Structural Composites, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Liang-Wen Feng
- Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610065, China
| | - Zheng Tang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Center for Advanced Low-dimension Materials, Donghua University, Shanghai 201620, China
| | - Jun Liu
- National Key Laboratory on Electromagnetic Environment Effects and Electro-Optical Engineering, Nanjing 210007, China
| | - Hengda Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Hongzhi Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Gang Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
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27
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Mascia A, Collu R, Spanu A, Fraschini M, Barbaro M, Cosseddu P. Wearable System Based on Ultra-Thin Parylene C Tattoo Electrodes for EEG Recording. SENSORS (BASEL, SWITZERLAND) 2023; 23:766. [PMID: 36679563 PMCID: PMC9861766 DOI: 10.3390/s23020766] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
In an increasingly interconnected world, where electronic devices permeate every aspect of our lives, wearable systems aimed at monitoring physiological signals are rapidly taking over the sport and fitness domain, as well as biomedical fields such as rehabilitation and prosthetics. With the intent of providing a novel approach to the field, in this paper we discuss the development of a wearable system for the acquisition of EEG signals based on a portable, low-power custom PCB specifically designed to be used in combination with non-conventional ultra-conformable and imperceptible Parylene-C tattoo electrodes. The proposed system has been tested in a standard rest-state experiment, and its performance in terms of discrimination of two different states has been compared to that of a commercial wearable device for EEG signal acquisition (i.e., the Muse headset), showing comparable results. This first preliminary validation demonstrates the possibility of conveniently employing ultra-conformable tattoo-electrodes integrated portable systems for the unobtrusive acquisition of brain activity.
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Affiliation(s)
- Antonello Mascia
- Department of Electrical and Electronics Engineering, University of Cagliari, Piazza D’Armi, 09123 Cagliari, Italy
| | - Riccardo Collu
- Department of Electrical and Electronics Engineering, University of Cagliari, Piazza D’Armi, 09123 Cagliari, Italy
| | - Andrea Spanu
- Department of Science, Technology and Society, Scuola Universitaria Superiore IUSS, Palazzo del Broletto, Piazza della Vittoria 15, 27100 Pavia, Italy
| | - Matteo Fraschini
- Department of Electrical and Electronics Engineering, University of Cagliari, Piazza D’Armi, 09123 Cagliari, Italy
| | - Massimo Barbaro
- Department of Electrical and Electronics Engineering, University of Cagliari, Piazza D’Armi, 09123 Cagliari, Italy
| | - Piero Cosseddu
- Department of Electrical and Electronics Engineering, University of Cagliari, Piazza D’Armi, 09123 Cagliari, Italy
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28
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Zhang Q, Ji K, Huo T, Khan MN, Hu Z, Yuan C, Zhao J, Chen J, Wang Z, Dai Z. Biomimetic Patch with Wicking-Breathable and Multi-mechanism Adhesion for Bioelectrical Signal Monitoring. ACS APPLIED MATERIALS & INTERFACES 2022; 14:48438-48448. [PMID: 36259961 DOI: 10.1021/acsami.2c13984] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Wearable bioelectrical monitoring devices can provide long-term human health information such as electrocardiogram and other physiological signals. It is a crucial part of the remote medical system. These can provide prediction for the diagnosis and treatment of cardiovascular disease and access to timely treatment. However, the patch comfort of the wearable monitoring devices in long-term contact with the skin have been a technical bottleneck of the hardware. In this study, the biomimetic patch with wicking-breathable and multi-mechanism adhesion performance to achieve adaptability and comfortability to human skin has been reported. The patch was designed based on a conical through-hole and hexagonal microgroove to directionally transport sweat from skin to air which gives the patch the breathable performance. The breathable and drainage capability of the biomimetic patch was experimentally verified by analyzing the conical through-hole and hexagonal microgroove with the structural mechanism of wicking. Multi-mechanism adhesion of the Ag/Ni microneedle array and PDMS-t adhesion material ensures the stability of patch signal acquisition. This study provides a new way for enhancing the breathability and adaptability of the patch to realize accurate bioelectrical signal monitoring under sweat conditions on human skin.
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Affiliation(s)
- Qian Zhang
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Keju Ji
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Tingwei Huo
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Muhammad Niaz Khan
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China
| | - Zhuoyang Hu
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Cong Yuan
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Jiahui Zhao
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Jian Chen
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Zhouyi Wang
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Zhendong Dai
- Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
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29
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Kim DY, Lee G, Lee GY, Kim J, Jeon K, Kim KS. Hybrid 1D/2D nanocarbon-based conducting polymer nanocomposites for high-performance wearable electrodes. NANOSCALE ADVANCES 2022; 4:4570-4578. [PMID: 36341283 PMCID: PMC9595188 DOI: 10.1039/d2na00220e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
A low interfacial contact resistance is a challenge in polymer nanocomposites based on conductive nanomaterials for high-performance wearable electrode applications. Herein, a polydimethylsiloxane (PDMS)-based flexible nanocomposite incorporating high-conductivity 1D single-walled carbon nanotubes (SWCNTs) and 2D reduced graphene oxide (r-GO) was developed for high-performance electrocardiogram (ECG) wearable electrodes. A PDMS-SWCNT (P-SW; type I) nanocomposite containing only SWCNTs (2 wt%), exhibited rough and non-uniform surface morphology owing to the strong bundling effect of as-grown SWCNTs and randomly entangled aggregate structures and because of inefficient vacuum degassing (i.e., R P-SW = 1871 Ω). In contrast, owing to the hybrid structure of the SWCNTs (1 wt%) and r-GO (1 wt%), the PDMS-SWCNTs/r-GO (P-SW/r-GO; type II) nanocomposite exhibited uniform surface characteristics and low contact resistance (i.e., R P-SW/r-GO = 63 Ω) through the formation of hybrid and long conducting pathways. The optimized nanocomposite (P-SW/r-GO/f; type III) possessed a fabric-assisted structure that enabled tunable and efficient vacuum degassing and curing conditions. Additionally, a long and wide conducting pathway was formed through more uniform and dense interconnected structures, and the contact resistance was drastically reduced (i.e., R P-SW/r-GO/f = 15 Ω). The performance of the electrodes fabricated using the optimized nanocomposites was the same or higher than that of commercial Ag/AgCl gel electrodes during real-time measurement for ECG Bluetooth monitoring. The developed high-performance hybrid conducting polymer electrodes are expected to contribute significantly to the expansion of the application scope of wearable electronic devices and wireless personal health monitoring systems.
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Affiliation(s)
- Dong Young Kim
- Convergence Research Division, Korea Carbon Industry Promotion Agency (KCARBON) 110-11 Banryong-ro, Deokjin-gu Jeonju 54852 Republic of Korea
| | - Geonhee Lee
- Department of Physics, Graphene Research Institute and GRI-TPC International Research Centre, Sejong University Seoul 05006 Republic of Korea
| | - Gil Yong Lee
- Department of Physics, Graphene Research Institute and GRI-TPC International Research Centre, Sejong University Seoul 05006 Republic of Korea
| | - Jungpil Kim
- Carbon & Light Materials Application Research Group, Korea Institute of Industrial Technology (KITECH) 222 Palbok-ro Deokjin-gu Jeonju 54853 Republic of Korea
| | - Kwangu Jeon
- E-Cube Materials 67, Yusang-ro, Deokjin-gu Jeonju 54852 Republic of Korea
| | - Keun Soo Kim
- Department of Physics, Graphene Research Institute and GRI-TPC International Research Centre, Sejong University Seoul 05006 Republic of Korea
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30
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Sang M, Kim K, Shin J, Yu KJ. Ultra-Thin Flexible Encapsulating Materials for Soft Bio-Integrated Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202980. [PMID: 36031395 PMCID: PMC9596833 DOI: 10.1002/advs.202202980] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/22/2022] [Indexed: 05/11/2023]
Abstract
Recently, bioelectronic devices extensively researched and developed through the convergence of flexible biocompatible materials and electronics design that enables more precise diagnostics and therapeutics in human health care and opens up the potential to expand into various fields, such as clinical medicine and biomedical research. To establish an accurate and stable bidirectional bio-interface, protection against the external environment and high mechanical deformation is essential for wearable bioelectronic devices. In the case of implantable bioelectronics, special encapsulation materials and optimized mechanical designs and configurations that provide electronic stability and functionality are required for accommodating various organ properties, lifespans, and functions in the biofluid environment. Here, this study introduces recent developments of ultra-thin encapsulations with novel materials that can preserve or even improve the electrical performance of wearable and implantable bio-integrated electronics by supporting safety and stability for protection from destruction and contamination as well as optimizing the use of bioelectronic systems in physiological environments. In addition, a summary of the materials, methods, and characteristics of the most widely used encapsulation technologies is introduced, thereby providing a strategic selection of appropriate choices of recently developed flexible bioelectronics.
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Affiliation(s)
- Mingyu Sang
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Kyubeen Kim
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Jongwoon Shin
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Ki Jun Yu
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
- YU‐KIST InstituteYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
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31
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Hsieh JC, Alawieh H, Li Y, Iwane F, Zhao L, Anderson R, Abdullah S, Kevin Tang KW, Wang W, Pyatnitskiy I, Jia Y, Millán JDR, Wang H. A highly stable electrode with low electrode-skin impedance for wearable brain-computer interface. Biosens Bioelectron 2022; 218:114756. [DOI: 10.1016/j.bios.2022.114756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/19/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022]
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32
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Li BM, Reese BL, Ingram K, Huddleston ME, Jenkins M, Zaets A, Reuter M, Grogg MW, Nelson MT, Zhou Y, Ju B, Sennik B, Farrell ZJ, Jur JS, Tabor CE. Textile-Integrated Liquid Metal Electrodes for Electrophysiological Monitoring. Adv Healthc Mater 2022; 11:e2200745. [PMID: 35734914 DOI: 10.1002/adhm.202200745] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/12/2022] [Indexed: 01/27/2023]
Abstract
Next generation textile-based wearable sensing systems will require flexibility and strength to maintain capabilities over a wide range of deformations. However, current material sets used for textile-based skin contacting electrodes lack these key properties, which hinder applications such as electrophysiological sensing. In this work, a facile spray coating approach to integrate liquid metal nanoparticle systems into textile form factors for conformal, flexible, and robust electrodes is presented. The liquid metal system employs functionalized liquid metal nanoparticles that provide a simple "peel-off to activate" means of imparting conductivity. The spray coating approach combined with the functionalized liquid metal system enables the creation of long-term reusable textile-integrated liquid metal electrodes (TILEs). Although the TILEs are dry electrodes by nature, they show equal skin-electrode impedances and sensing capabilities with improved wearability compared to commercial wet electrodes. Biocompatibility of TILEs in an in vivo skin environment is demonstrated, while providing improved sensing performance compared to previously reported textile-based dry electrodes. The "spray on dry-behave like wet" characteristics of TILEs opens opportunities for textile-based wearable health monitoring, haptics, and augmented/virtual reality applications that require the use of flexible and conformable dry electrodes.
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Affiliation(s)
- Braden M Li
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, 27606, USA.,Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA.,Air Force Life Cycle Management Center, Human Systems Division, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Brandon L Reese
- Department of Physics, Miami University, Oxford, OH, 45056, USA.,UES Inc, Dayton, OH, 45432, USA
| | - Katherine Ingram
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Mary E Huddleston
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Meghan Jenkins
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Allison Zaets
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Matthew Reuter
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Matthew W Grogg
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - M Tyler Nelson
- Air Force Research Laboratory, 711th Human Performance Wing, Airman Systems Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
| | - Ying Zhou
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, 27606, USA
| | - Beomjun Ju
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, 27606, USA
| | - Busra Sennik
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, 27606, USA
| | - Zachary J Farrell
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA.,UES Inc, Dayton, OH, 45432, USA
| | - Jesse S Jur
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC, 27606, USA
| | - Christopher E Tabor
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, OH, 45433, USA
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33
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Lo LW, Zhao J, Aono K, Li W, Wen Z, Pizzella S, Wang Y, Chakrabartty S, Wang C. Stretchable Sponge Electrodes for Long-Term and Motion-Artifact-Tolerant Recording of High-Quality Electrophysiologic Signals. ACS NANO 2022; 16:11792-11801. [PMID: 35861486 PMCID: PMC9413418 DOI: 10.1021/acsnano.2c04962] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/15/2022] [Indexed: 05/27/2023]
Abstract
Soft electronic devices and sensors have shown great potential for wearable and ambulatory electrophysiologic signal monitoring applications due to their light weight, ability to conform to human skin, and improved wearing comfort, and they may replace the conventional rigid electrodes and bulky recording devices widely used nowadays in clinical settings. Herein, we report an elastomeric sponge electrode that offers greatly reduced electrode-skin contact impedance, an improved signal-to-noise ratio (SNR), and is ideally suited for long-term and motion-artifact-tolerant recording of high-quality biopotential signals. The sponge electrode utilizes a porous polydimethylsiloxane sponge made from a sacrificial template of sugar cubes, and it is subsequently coated with a poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) conductive polymer using a simple dip-coating process. The sponge electrode contains numerous micropores that greatly increase the skin-electrode contact area and help lower the contact impedance by a factor of 5.25 or 6.7 compared to planar PEDOT:PSS electrodes or gold-standard Ag/AgCl electrodes, respectively. The lowering of contact impedance resulted in high-quality electrocardiogram (ECG) and electromyogram (EMG) recordings with improved SNR. Furthermore, the porous structure also allows the sponge electrode to hold significantly more conductive gel compared to conventional planar electrodes, thereby allowing them to be used for long recording sessions with minimal signal degradation. The conductive gel absorbed into the micropores also serves as a buffer layer to help mitigate motion artifacts, which is crucial for recording on ambulatory patients. Lastly, to demonstrate its feasibility and potential for clinical usage, we have shown that the sponge electrode can be used to monitor uterine contraction activities from a patient in labor. With its low-cost fabrication, softness, and ability to record high SNR biopotential signals, the sponge electrode is a promising platform for long-term wearable health monitoring applications.
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Affiliation(s)
- Li-Wei Lo
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Institute
of Materials Science and Engineering, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Junyi Zhao
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Kenji Aono
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Weilun Li
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Zichao Wen
- Department
of Obstetrics & Gynecology, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Stephanie Pizzella
- Department
of Obstetrics & Gynecology, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Yong Wang
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Department
of Obstetrics & Gynecology, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
| | - Shantanu Chakrabartty
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Chuan Wang
- Department
of Electrical & Systems Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
- Institute
of Materials Science and Engineering, Washington
University in St. Louis, St. Louis, Missouri 63130, United States
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Niu X, Gao X, Wang T, Wang W, Liu H. Ordered Nanopillar Arrays of Low Dynamic Noise Dry Bioelectrodes for Electrocardiogram Surface Monitoring. ACS APPLIED MATERIALS & INTERFACES 2022; 14:33861-33870. [PMID: 35830904 DOI: 10.1021/acsami.2c08318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Flexible bioelectric dry electrodes are an important part of long-term medical healthcare monitoring systems. In this study, a new method is proposed for the preparation of dry electrodes with micronanopillar arrays structured by designing dimensionally tunable anodized aluminum oxide (AAO) templates, by which polyaniline/thermoplastic polyurethane single-layer micronanopillar array structured dry electrodes (PANI/TPU-SE) and polyaniline/thermoplastic polyurethane double-layer micronanopillar array structured dry electrodes (PANI/TPU-DE) are prepared. Compared with the planar structure, the micronanopillar array structure can reduce the contact gap between the electrode and skin and increase the contact area, thus exhibiting lower contact impedance and higher signal quality. At 0.1 Hz, the impedances of the wet electrode, PANI/TPU-DE300, PANI/TPU-SE10, and planar structure electrodes are 269.5 kΩ, 375.5 kΩ, 398.1 kΩ, and 2.257 MΩ, respectively, and the impedance value for PANI/TPU-DE300 is smaller than that for PANI/TPU-SE10 and closer to that for the wet electrode. In addition, because the surface of the micronanostructure can conform to the human skin, about 210.7% increase in the peel strength of double-layer structure electrodes compared to flat structure electrodes, it shows a low baseline drift in the dynamic ECG measurement, and the signal-to-noise ratio in the walking state can reach 21.33 ± 5.4775 dB. Therefore, the prepared bioelectric dry electrode has a wide application prospect in the fields of wearable medical monitoring.
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Affiliation(s)
- Xin Niu
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Xinhua Gao
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Tanyu Wang
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Wei Wang
- School of Arts, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Hao Liu
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
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35
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Lee DH, Lee EK, Kim CH, Yun HJ, Kim YJ, Yoo H. Blended Polymer Dry Electrodes for Reliable Electrocardiogram and Electromyogram Measurements and Their Eco-Friendly Disposal Led by Degradability in Hot Water. Polymers (Basel) 2022; 14:polym14132586. [PMID: 35808632 PMCID: PMC9269162 DOI: 10.3390/polym14132586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/19/2022] [Accepted: 06/21/2022] [Indexed: 02/05/2023] Open
Abstract
To increase the human lifespan, healthcare monitoring devices that diagnose diseases and check body conditions have attracted considerable interest. Commercial AgCl-based wet electrodes with the advantages of high conductivity and strong adaptability to human skin are considered the most frequently used electrode material for healthcare monitoring. However, commercial AgCl-based wet electrodes, when exposed for a long period, cause an evaporation of organic solvents, which could reduce the signal-to-noise ratio of biosignals and stimulate human skin. In this context, we demonstrate a dry electrode for a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based blended polymer electrode using a combination of PEDOT:PSS, waterborne polyurethane (WPU) and ethylene glycol (EG) that could be reused for a long period of time to detect electrocardiography (ECG) and electromyography (EMG). Both ECG and EMG are reliably detected by the wireless real-time monitoring system. In particular, the proposed dry electrode detects biosignals without deterioration for over 2 weeks. Additionally, a double layer of a polyimide (PI) substrate and fluorinated polymer CYTOP induces the strong waterproof characteristics of external liquids for the proposed dry electrodes, having a low surface energy of 14.49 mN/m. In addition, the proposed electrode has excellent degradability in water; it dissolves in hot water at 60 °C.
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Affiliation(s)
- Dong Hyun Lee
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam 13120, Korea; (D.H.L.); (C.H.K.)
| | - Eun Kwang Lee
- Department of Chemical Engineering, Pukyong National University (PKNU), Busan 48513, Korea;
| | - Chae Hyun Kim
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam 13120, Korea; (D.H.L.); (C.H.K.)
| | - Hyung Joong Yun
- Advance Nano Research Group, Korea Basic Science Institute (KBSI), Daejeon 34126, Korea;
| | - Young-Joon Kim
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam 13120, Korea; (D.H.L.); (C.H.K.)
- Correspondence: (Y.-J.K.); (H.Y.)
| | - Hocheon Yoo
- Department of Electronic Engineering, Gachon University, 1342 Seongnam-daero, Seongnam 13120, Korea; (D.H.L.); (C.H.K.)
- Correspondence: (Y.-J.K.); (H.Y.)
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36
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Kim H, Kim S, Lim D, Jeong W. Development and Characterization of Embroidery-Based Textile Electrodes for Surface EMG Detection. SENSORS (BASEL, SWITZERLAND) 2022; 22:4746. [PMID: 35808240 PMCID: PMC9268917 DOI: 10.3390/s22134746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
The interest in wearable devices has expanded to measurement devices for building IoT-based mobile healthcare systems and sensing bio-signal data through clothing. Surface electromyography, called sEMG, is one of the most popular bio-signals that can be applied to health monitoring systems. In general, gel-based (Ag/AgCl) electrodes are mainly used, but there are problems, such as skin irritation due to long-time wearing, deterioration of adhesion to the skin due to moisture or sweat, and low applicability to clothes. Hence, research on dry electrodes as a replacement is increasing. Accordingly, in this study, a textile-based electrode was produced with a range of electrode shapes, and areas were embroidered with conductive yarn using an embroidery technique in the clothing manufacturing process. The electrode was applied to EMG smart clothing for fitness, and the EMG signal detection performance was analyzed. The electrode shape was manufactured using the circle and wave type. The wave-type electrode was more morphologically stable than the circle-type electrode by up to 30% strain, and the electrode shape was maintained as the embroidered area increased. Skin-electrode impedance analysis confirmed that the embroidered area with conductive yarn affected the skin contact area, and the impedance decreased with increasing area. For sEMG performance analysis, the rectus femoris was selected as a target muscle, and the sEMG parameters were analyzed. The wave-type sample showed higher EMG signal strength than the circle-type. In particular, the electrode with three lines showed better performance than the fill-type electrode. These performances operated without noise, even with a commercial device. Therefore, it is expected to be applicable to the manufacture of electromyography smart clothing based on embroidered electrodes in the future.
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Affiliation(s)
- Hyelim Kim
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea; (H.K.); (D.L.)
| | - Siyeon Kim
- Reliability Assesment Center, FITI Testing and Research Institute, Seoul 07791, Korea;
| | - Daeyoung Lim
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea; (H.K.); (D.L.)
| | - Wonyoung Jeong
- Material and Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea; (H.K.); (D.L.)
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37
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Li J, Ma Y, Huang D, Wang Z, Zhang Z, Ren Y, Hong M, Chen Y, Li T, Shi X, Cao L, Zhang J, Jiao B, Liu J, Sun H, Li Z. High-Performance Flexible Microneedle Array as a Low-Impedance Surface Biopotential Dry Electrode for Wearable Electrophysiological Recording and Polysomnography. NANO-MICRO LETTERS 2022; 14:132. [PMID: 35699782 PMCID: PMC9198145 DOI: 10.1007/s40820-022-00870-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/20/2022] [Indexed: 06/01/2023]
Abstract
Polyimide-based flexible microneedle array (PI-MNA) electrodes realize high electrical/mechanical performance and are compatible with wearable wireless recording systems. The normalized electrode-skin interface impedance (EII) of the PI-MNA electrodes reaches 0.98 kΩ cm2 at 1 kHz and 1.50 kΩ cm2 at 10 Hz, approximately 1/250 of clinical standard electrodes. This is the first report on the clinical study of microneedle electrodes. The PI-MNA electrodes are applied to clinical long-term continuous monitoring for polysomnography. Microneedle array (MNA) electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications. Existing schemes are limited by flexibility, biosafety, and manufacturing costs, which create large barriers for wider applications. Here, we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface, robustness of microneedles to penetrate the skin without fracture, and a simplified process to allow mass production. The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording. The normalized electrode-skin contact impedance reaches 0.98 kΩ cm2 at 1 kHz and 1.50 kΩ cm2 at 10 Hz, a record low value compared to previous reports and approximately 1/250 of the standard electrodes. The morphology, biosafety, and electrical/mechanical properties are fully characterized, and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized. The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording (over 8 h per night), providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.
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Affiliation(s)
- Junshi Li
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Yundong Ma
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, People's Republic of China
| | - Dong Huang
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
- School of Electronics, Peking University, Beijing, 100871, People's Republic of China
- Hypnometry Microsystem, Beijing, 100871, People's Republic of China
| | - Zhongyan Wang
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Zhitong Zhang
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Yingjie Ren
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Mengyue Hong
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, People's Republic of China
| | - Yufeng Chen
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Tingyu Li
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Xiaoyi Shi
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Lu Cao
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
- College of Engineering, Peking University, Beijing, 100871, People's Republic of China
| | - Jiayan Zhang
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Bingli Jiao
- School of Electronics, Peking University, Beijing, 100871, People's Republic of China
| | - Junhua Liu
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China
| | - Hongqiang Sun
- Peking University Sixth Hospital, Peking University Institute of Mental Health, NHC Key Laboratory of Mental Health (Peking University), National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital), Beijing, 100191, People's Republic of China.
| | - Zhihong Li
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, School of Integrated Circuits, Peking University, Beijing, 100871, People's Republic of China.
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Hsieh JC, Li Y, Wang H, Perz M, Tang Q, Tang KWK, Pyatnitskiy I, Reyes R, Ding H, Wang H. Design of hydrogel-based wearable EEG electrodes for medical applications. J Mater Chem B 2022; 10:7260-7280. [PMID: 35678148 DOI: 10.1039/d2tb00618a] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The electroencephalogram (EEG) is considered to be a promising method for studying brain disorders. Because of its non-invasive nature, subjects take a lower risk compared to some other invasive methods, while the systems record the brain signal. With the technological advancement of neural and material engineering, we are in the process of achieving continuous monitoring of neural activity through wearable EEG. In this article, we first give a brief introduction to EEG bands, circuits, wired/wireless EEG systems, and analysis algorithms. Then, we review the most recent advances in the interfaces used for EEG recordings, focusing on hydrogel-based EEG electrodes. Specifically, the advances for important figures of merit for EEG electrodes are reviewed. Finally, we summarize the potential medical application of wearable EEG systems.
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Affiliation(s)
- Ju-Chun Hsieh
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Yang Li
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3C3J7, Canada
| | - Huiqian Wang
- Department of Mathematics, The University of Texas at Austin, Austin, TX 78712, USA
| | - Matt Perz
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Qiong Tang
- Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kai Wing Kevin Tang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Ilya Pyatnitskiy
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Raymond Reyes
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Hong Ding
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Huiliang Wang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
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39
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Substrate-free, ultra-conformable PEDOT: PSS E-tattoo achieved by energy regulation on skin. Biosens Bioelectron 2022; 206:114118. [DOI: 10.1016/j.bios.2022.114118] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 11/20/2022]
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Graphene-Based Flexible Electrode for Electrocardiogram Signal Monitoring. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12094526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
With the rapidly aging society and increased concern for personal cardiovascular health, novel, flexible electrodes suitable for electrocardiogram (ECG) signal monitoring are in demand. Based on the excellent electrical and mechanical properties of graphene and the rapid development of graphene device fabrication technologies, graphene-based ECG electrodes have recently attracted much attention, and many flexible graphene electrodes with excellent performance have been developed. To understand the current research progress of graphene-based ECG electrodes and help researchers clarify current development conditions and directions, we systematically review the recent advances in graphene-based flexible ECG electrodes. Graphene electrodes are classified as bionic, fabric-based, biodegradable, laser-induced/scribed, modified-graphene, sponge-like, invasive, etc., based on their design concept, structural characteristics, preparation methods, and material properties. Moreover, some categories are further divided into dry or wet electrodes. Then, their performance, including electrode–skin impedance, signal-to-noise ratio, skin compatibility, and stability, is analyzed. Finally, we discuss possible development directions of graphene ECG electrodes and share our views.
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Hu M, Zhang J, Liu Y, Zheng X, Li X, Li X, Yang H. Highly Conformal Polymers for Ambulatory Electrophysiological Sensing. Macromol Rapid Commun 2022; 43:e2200047. [PMID: 35419904 DOI: 10.1002/marc.202200047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 04/09/2022] [Indexed: 11/08/2022]
Abstract
Stable ambulatory electrophysiological sensing is widely utilized for smart e-healthcare monitoring, clinical diagnosis of cardiovascular diseases, treatment of neurological diseases, and intelligent human-machine interaction. As the favorable signal interaction platform of electrophysiological sensing, the conformal property of on-skin electrodes is an extremely crucial factor that can affect the stability of long-term ambulatory electrophysiological sensing. From the perspective of materials, to realize conformal contact between electrodes and skin for stable sensing, highly conformal polymers are strongly demanding and attracting ever-growing attention. In this review, we focused on the recent progress of highly conformal polymers for ambulatory electrophysiological sensing, including their synthetic methods, conformal property, and potential applications. Specifically, three main types of highly conformal polymers for stable long-term electrophysiological signals monitoring were proposed, including nature silk fibroin based conformal polymers, marine mussels bio-inspired conformal polymers, and other conformal polymers such as zwitterionic polymers and polyacrylamide. Furthermore, the future challenges and opportunities of preparing highly conformal polymers for on-skin electrodes were also highlighted. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mingshuang Hu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
| | - Jun Zhang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
| | - Yixuan Liu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
| | - Xinran Zheng
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
| | - Xiangxiang Li
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
| | - Ximing Li
- Chest hospital, Tianjin University, Tianjin, 300072, China
| | - Hui Yang
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, School of Science, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin, 300072, China
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42
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Mahmood M, Kim N, Mahmood M, Kim H, Kim H, Rodeheaver N, Sang M, Yu KJ, Yeo WH. VR-enabled portable brain-computer interfaces via wireless soft bioelectronics. Biosens Bioelectron 2022; 210:114333. [DOI: 10.1016/j.bios.2022.114333] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/19/2022] [Accepted: 04/26/2022] [Indexed: 11/02/2022]
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Oh J, Jang SG, Moon S, Kim J, Park HK, Kim HS, Park S, Jeong U. Air-Permeable Waterproofing Electrocardiogram Patch to Monitor Full-Day Activities for Multiple Days. Adv Healthc Mater 2022; 11:e2102703. [PMID: 35285162 DOI: 10.1002/adhm.202102703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/14/2022] [Indexed: 11/10/2022]
Abstract
On-skin healthcare patch-type devices have great technological challenges in monitoring full-day activities and wearing for multiple days without detachment. These challenges can be overcome when the sensor is air permeable but waterproof. This study presents a light-weight, highly stable, and stretchable Au electrode that is fabricated by sputtering on an imidized nanofiber mat. The contact surface of the electrode is hydro-wetting and the outer surface of the electrode is hydrophobic, so the porous electrode simultaneously has excellent sweat permeability and waterproofing capabilities. The electrode is applied to the electrocardiogram sensor for monitoring the cardiac signals for five consecutive days without detaching while doing various full-day activities such as relaxing, exercising, showering, and sleeping. This study suggests a modular setup of the electrodes and the cardiac signal processing unit for activating the device when cardiac monitoring is required.
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Affiliation(s)
- Joosung Oh
- Department of Materials Science and Engineering Pohang University of Science and Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Seok Geun Jang
- Department of Electrical Engineering Pohang University of Science Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Sungmin Moon
- Department of Materials Science and Engineering Pohang University of Science and Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Junho Kim
- School of Interdisciplinary Bioscience and Bioengineering Pohang University of Science Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Hyung Keun Park
- Department of Materials Science and Engineering Pohang University of Science and Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Hyoung Seop Kim
- Department of Materials Science and Engineering Pohang University of Science and Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Sung‐Min Park
- Department of convergence IT engineering Electrical Engineering and Mechanical Engineering Pohang University of Science Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
| | - Unyong Jeong
- Department of Materials Science and Engineering Pohang University of Science and Technology 77 Cheongam‐Ro Nam‐Gu Pohang 37673 Korea
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44
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Niu X, Wang L, Li H, Wang T, Liu H, He Y. Fructus Xanthii-Inspired Low Dynamic Noise Dry Bioelectrodes for Surface Monitoring of ECG. ACS APPLIED MATERIALS & INTERFACES 2022; 14:6028-6038. [PMID: 35044157 DOI: 10.1021/acsami.1c22303] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The microstructured surfaces of bioelectrical dry electrodes are important aspects of dry electrode design. However, traditional surfaces for microstructured bioelectrical dry electrodes are costly to produce and require complex fabrication methods. In this study, a novel stacked-template method is proposed for the first time, rapidly producing microstructured dry electrodes at a low cost and with a large surface area. Three types of microstructured Ag/AgCl thermoplastic polyurethane (TPU) electrodes with a Fructus xanthii-inspired barb structure (FXbs) are prepared using this method; then, the dynamic friction, hair interference resistance, electrochemical, and electrocardiogram (ECG) signal acquisition performance of the electrodes are tested, and the dynamic noise characteristics of the electrodes are comprehensively evaluated with simulated instruments. Compared to the plate structure, the dynamic friction coefficient of the FXbs electrode improved by about 38.8%, exhibiting strong hair interference resistance. In addition, the FXbs electrode exhibits low dynamic noise and comparable performance to the wet electrode, in terms of signal acquisition, when it is tested using simulated instruments. Therefore, the prepared FXbs electrode increases the friction coefficient between the electrode and the skin, which effectively resolves issues related to dynamic noise in bioelectrical signals, making it suitable for dynamic measurements.
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Affiliation(s)
- Xin Niu
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Lingzhu Wang
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Hui Li
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Tanyu Wang
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Hao Liu
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
| | - Yin He
- School of Textile Science and Engineering, Institute of Smart Wearable Electronic Textiles, Tiangong University, Tianjin 300387, P. R. China
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Cho KW, Sunwoo SH, Hong YJ, Koo JH, Kim JH, Baik S, Hyeon T, Kim DH. Soft Bioelectronics Based on Nanomaterials. Chem Rev 2021; 122:5068-5143. [PMID: 34962131 DOI: 10.1021/acs.chemrev.1c00531] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent advances in nanostructured materials and unconventional device designs have transformed the bioelectronics from a rigid and bulky form into a soft and ultrathin form and brought enormous advantages to the bioelectronics. For example, mechanical deformability of the soft bioelectronics and thus its conformal contact onto soft curved organs such as brain, heart, and skin have allowed researchers to measure high-quality biosignals, deliver real-time feedback treatments, and lower long-term side-effects in vivo. Here, we review various materials, fabrication methods, and device strategies for flexible and stretchable electronics, especially focusing on soft biointegrated electronics using nanomaterials and their composites. First, we summarize top-down material processing and bottom-up synthesis methods of various nanomaterials. Next, we discuss state-of-the-art technologies for intrinsically stretchable nanocomposites composed of nanostructured materials incorporated in elastomers or hydrogels. We also briefly discuss unconventional device design strategies for soft bioelectronics. Then individual device components for soft bioelectronics, such as biosensing, data storage, display, therapeutic stimulation, and power supply devices, are introduced. Afterward, representative application examples of the soft bioelectronics are described. A brief summary with a discussion on remaining challenges concludes the review.
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Affiliation(s)
- Kyoung Won Cho
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Sung-Hyuk Sunwoo
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Yongseok Joseph Hong
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Ja Hoon Koo
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Jeong Hyun Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea
| | - Seungmin Baik
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 08826, Republic of Korea.,School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Dae-Hyeong Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.,Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 08826, Republic of Korea.,School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea.,Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
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46
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Khan MA, Saibene M, Das R, Brunner IC, Puthusserypady S. Emergence of flexible technology in developing advanced systems for post-stroke rehabilitation: a comprehensive review. J Neural Eng 2021; 18. [PMID: 34736239 DOI: 10.1088/1741-2552/ac36aa] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/04/2021] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Stroke is one of the most common neural disorders, which causes physical disabilities and motor impairments among its survivors. Several technologies have been developed for providing stroke rehabilitation and to assist the survivors in performing their daily life activities. Currently, the use of flexible technology (FT) for stroke rehabilitation systems is on a rise that allows the development of more compact and lightweight wearable systems, which stroke survivors can easily use for long-term activities. APPROACH For stroke applications, FT mainly includes the "flexible/stretchable electronics", "e-textile (electronic textile)" and "soft robotics". Thus, a thorough literature review has been performed to report the practical implementation of FT for post-stroke application. MAIN RESULTS In this review, the highlights of the advancement of FT in stroke rehabilitation systems are dealt with. Such systems mainly involve the "biosignal acquisition unit", "rehabilitation devices" and "assistive systems". In terms of biosignals acquisition, electroencephalography (EEG) and electromyography (EMG) are comprehensively described. For rehabilitation/assistive systems, the application of functional electrical stimulation (FES) and robotics units (exoskeleton, orthosis, etc.) have been explained. SIGNIFICANCE This is the first review article that compiles the different studies regarding flexible technology based post-stroke systems. Furthermore, the technological advantages, limitations, and possible future implications are also discussed to help improve and advance the flexible systems for the betterment of the stroke community.
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Affiliation(s)
- Muhammad Ahmed Khan
- Technical University of Denmark, Ørsteds Plads Building 345C, Room 215, Lyngby, 2800, DENMARK
| | - Matteo Saibene
- Technical University of Denmark, Ørsteds Plads, Building 345C, Lyngby, 2800, DENMARK
| | - Rig Das
- Technical University of Denmark, Ørsteds Plads Building 345C, Room 214, Lyngby, 2800, DENMARK
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Mahmood M, Kwon S, Kim H, Kim Y, Siriaraya P, Choi J, Otkhmezuri B, Kang K, Yu KJ, Jang YC, Ang CS, Yeo W. Wireless Soft Scalp Electronics and Virtual Reality System for Motor Imagery-Based Brain-Machine Interfaces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101129. [PMID: 34272934 PMCID: PMC8498913 DOI: 10.1002/advs.202101129] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/01/2021] [Indexed: 05/23/2023]
Abstract
Motor imagery offers an excellent opportunity as a stimulus-free paradigm for brain-machine interfaces. Conventional electroencephalography (EEG) for motor imagery requires a hair cap with multiple wired electrodes and messy gels, causing motion artifacts. Here, a wireless scalp electronic system with virtual reality for real-time, continuous classification of motor imagery brain signals is introduced. This low-profile, portable system integrates imperceptible microneedle electrodes and soft wireless circuits. Virtual reality addresses subject variance in detectable EEG response to motor imagery by providing clear, consistent visuals and instant biofeedback. The wearable soft system offers advantageous contact surface area and reduced electrode impedance density, resulting in significantly enhanced EEG signals and classification accuracy. The combination with convolutional neural network-machine learning provides a real-time, continuous motor imagery-based brain-machine interface. With four human subjects, the scalp electronic system offers a high classification accuracy (93.22 ± 1.33% for four classes), allowing wireless, real-time control of a virtual reality game.
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Affiliation(s)
- Musa Mahmood
- George W. Woodruff School of Mechanical EngineeringCollege of EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Center for Human‐Centric Interfaces and EngineeringInstitute for Electronics and NanotechnologyGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Shinjae Kwon
- George W. Woodruff School of Mechanical EngineeringCollege of EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Center for Human‐Centric Interfaces and EngineeringInstitute for Electronics and NanotechnologyGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Hojoong Kim
- George W. Woodruff School of Mechanical EngineeringCollege of EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Center for Human‐Centric Interfaces and EngineeringInstitute for Electronics and NanotechnologyGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Yun‐Soung Kim
- George W. Woodruff School of Mechanical EngineeringCollege of EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Center for Human‐Centric Interfaces and EngineeringInstitute for Electronics and NanotechnologyGeorgia Institute of TechnologyAtlantaGA30332USA
| | | | - Jeongmoon Choi
- School of Biological Sciences, College of SciencesGeorgia Institute of TechnologyAtlantaGA30332USA
| | | | - Kyowon Kang
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Ki Jun Yu
- School of Electrical and Electronic EngineeringYonsei UniversitySeoul03722Republic of Korea
| | - Young C. Jang
- School of Biological Sciences, College of SciencesGeorgia Institute of TechnologyAtlantaGA30332USA
| | - Chee Siang Ang
- School of ComputingUniversity of KentCanterburyKentCT2 7NTUK
| | - Woon‐Hong Yeo
- George W. Woodruff School of Mechanical EngineeringCollege of EngineeringGeorgia Institute of TechnologyAtlantaGA30332USA
- Center for Human‐Centric Interfaces and EngineeringInstitute for Electronics and NanotechnologyGeorgia Institute of TechnologyAtlantaGA30332USA
- Wallace H. Coulter Department of Biomedical EngineeringParker H. Petit Institute for Bioengineering and BiosciencesInstitute for MaterialsNeural Engineering CenterInstitute for Robotics and Intelligent MachinesGeorgia Institute of TechnologyAtlantaGA30332USA
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48
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Portillo-Lara R, Tahirbegi B, Chapman CAR, Goding JA, Green RA. Mind the gap: State-of-the-art technologies and applications for EEG-based brain-computer interfaces. APL Bioeng 2021; 5:031507. [PMID: 34327294 PMCID: PMC8294859 DOI: 10.1063/5.0047237] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/19/2021] [Indexed: 11/14/2022] Open
Abstract
Brain-computer interfaces (BCIs) provide bidirectional communication between the brain and output devices that translate user intent into function. Among the different brain imaging techniques used to operate BCIs, electroencephalography (EEG) constitutes the preferred method of choice, owing to its relative low cost, ease of use, high temporal resolution, and noninvasiveness. In recent years, significant progress in wearable technologies and computational intelligence has greatly enhanced the performance and capabilities of EEG-based BCIs (eBCIs) and propelled their migration out of the laboratory and into real-world environments. This rapid translation constitutes a paradigm shift in human-machine interaction that will deeply transform different industries in the near future, including healthcare and wellbeing, entertainment, security, education, and marketing. In this contribution, the state-of-the-art in wearable biosensing is reviewed, focusing on the development of novel electrode interfaces for long term and noninvasive EEG monitoring. Commercially available EEG platforms are surveyed, and a comparative analysis is presented based on the benefits and limitations they provide for eBCI development. Emerging applications in neuroscientific research and future trends related to the widespread implementation of eBCIs for medical and nonmedical uses are discussed. Finally, a commentary on the ethical, social, and legal concerns associated with this increasingly ubiquitous technology is provided, as well as general recommendations to address key issues related to mainstream consumer adoption.
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Affiliation(s)
- Roberto Portillo-Lara
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Bogachan Tahirbegi
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Christopher A. R. Chapman
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Josef A. Goding
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
| | - Rylie A. Green
- Department of Bioengineering, Imperial College London, Royal School of Mines, London SW7 2AZ, United Kingdom
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49
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Zhu M, Wang H, Li S, Liang X, Zhang M, Dai X, Zhang Y. Flexible Electrodes for In Vivo and In Vitro Electrophysiological Signal Recording. Adv Healthc Mater 2021; 10:e2100646. [PMID: 34050635 DOI: 10.1002/adhm.202100646] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/10/2021] [Indexed: 12/19/2022]
Abstract
A variety of electrophysiological signals (electrocardiography, electromyography, electroencephalography, etc.) are generated during the physiological activities of human bodies, which can be collected by electrodes and thus provide critical insights into health status or facilitate fundamental scientific research. The long-term stable and high-quality recording of electrophysiological signals is the premise for their further applications, leading to demands for flexible electrodes with similar mechanical modulus and minimized irritation to human bodies. This review summarizes the latest advances in flexible electrodes for the acquisition of various electrophysiological signals. First, the concept of electrophysiological signals and the characteristics of different subcategory signals are introduced. Second, the invasive and noninvasive methods are reviewed for electrophysiological signal recording with a highlight on the design of flexible electrodes, followed by a discussion on their material selection. Subsequently, the applications of the electrophysiological signal acquisition in pathological diagnosis and restoration of body functions are discussed, showing the advantages of flexible electrodes. Finally, the main challenges and opportunities in this field are discussed. It is believed that the further exploration of materials for flexible electrodes and the combination of multidisciplinary technologies will boost the applications of flexible electrodes for medical diagnosis and human-machine interface.
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Affiliation(s)
- Mengjia Zhu
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Huimin Wang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Shuo Li
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Xiaoping Liang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Mingchao Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
| | - Xiaochuan Dai
- Department of Biomedical Engineering School of Medicine Tsinghua University Beijing 100084 P. R. China
| | - Yingying Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084 P. R. China
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50
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Gogurla N, Kim Y, Cho S, Kim J, Kim S. Multifunctional and Ultrathin Electronic Tattoo for On-Skin Diagnostic and Therapeutic Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008308. [PMID: 33955069 DOI: 10.1002/adma.202008308] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/10/2021] [Indexed: 05/02/2023]
Abstract
Epidermal electronic systems for detecting electrophysiological signals, sensing, therapy, and drug delivery are at the frontier in man-machine interfacing for healthcare. However, it is still a challenge to develop multifunctional bioapplications with minimal invasiveness, biocompatibility, and stable electrical performance under various mechanical deformations of biological tissues. In this study, a natural silk protein with carbon nanotubes (CNTs) is utilized to realize an epidermal electronic tattoo (E-tattoo) system for multifunctional applications that address these challenging issues through dispersing highly conductive CNTs onto the biocompatible silk nanofibrous networks with porous nature to construct skin-adhesive ultrathin electronic patches. Individual components that incorporate electrically and optically active heaters, a temperature sensor (temperature coefficient of resistance of 5.2 × 10-3 °C-1 ), a stimulator for drug delivery (>500 µm penetration depth in skin), and real-time electrophysiological signal detectors are described. This strategy of E-tattoos integrated onto human skin can open a new route to a next-generation electronic platform for wearable and epidermal bioapplications.
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Affiliation(s)
- Narendar Gogurla
- Basic Science Research Center, Department of Physics, and Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea
| | - Yisub Kim
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Suyoung Cho
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Jangsun Kim
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Sunghwan Kim
- Basic Science Research Center, Department of Physics, and Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea
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