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Zadan M, Hu Y, Lipp J, Vinciguerra M, Lewis N, Shah D, Islam MF, Nepal D, Grasinger M, Dayal K, Tabor C, Majidi C. MXene-Coated Liquid Metal Nanodroplet Aggregates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2025; 41:8834-8841. [PMID: 40138582 PMCID: PMC11984108 DOI: 10.1021/acs.langmuir.5c00173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2025] [Revised: 03/20/2025] [Accepted: 03/20/2025] [Indexed: 03/29/2025]
Abstract
Combining droplets of liquid metal (LM) with nanomaterials often introduces synergistic thermal or electrical properties that are not found in the constituent materials alone. However, in these existing systems, LM droplets maintain a statistically uniform dispersion and are not capable of self-assembly or aggregation. These composites are limited by their need for high volume fractions of LM (>60 vol %) to achieve high thermal properties, introducing LM leaking as a drawback for thermal management and wearable electronic applications. In this work, we show that coating nanoscale droplets of eutectic gallium-indium (EGaIn) LM with small volume fractions of Ti3C2Tx MXenes (0.25 vol %) results in a unique LM morphology in which droplets self-assemble to form semisolid aggregates. This is accomplished by wrapping MXene sheets around individual LM droplets to create "sticky" particles that form self-assembled aggregates when mixed with a silicone oil. By introducing aggregation as a design parameter in soft LM composites, the thermal and electric resistance of the composite is shown to change dramatically. In contrast to silicone-based composites containing LM droplets or MXene nanosheets alone, these MXene-LM-silicone-based composites exhibit an exponential increase in thermal and electrical conductivity with decreasing interfacial thickness with significantly lower LM volume fractions (25 vol %) while avoiding LM rupture and bleed-out. This could enable more effective composites, reducing the amount of filler material required for thermal interface materials (TIM) and printed electronics.
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Affiliation(s)
- Mason Zadan
- Mechanical
Engineering Department, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Yafeng Hu
- Mechanical
Engineering Department, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Jeremiah Lipp
- Materials
and Manufacturing Directorate, Air Force
Research Laboratory, Dayton, Ohio 45433, United States
| | - Michael Vinciguerra
- Mechanical
Engineering Department, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Neal Lewis
- Materials
Science and Engineering Department, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Dylan Shah
- Arieca
Inc., Pittsburgh, Pennsylvania 15208, United States
| | - Mohammad F. Islam
- Materials
Science and Engineering Department, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Dhriti Nepal
- Materials
and Manufacturing Directorate, Air Force
Research Laboratory, Dayton, Ohio 45433, United States
| | - Matthew Grasinger
- Materials
and Manufacturing Directorate, Air Force
Research Laboratory, Dayton, Ohio 45433, United States
| | - Kaushik Dayal
- Civil
and Environmental Engineering Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Christopher Tabor
- Materials
and Manufacturing Directorate, Air Force
Research Laboratory, Dayton, Ohio 45433, United States
| | - Carmel Majidi
- Mechanical
Engineering Department, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
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2
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Lee S, Jaseem SA, Atar N, Wang M, Kim JY, Zare M, Kim S, Bartlett MD, Jeong JW, Dickey MD. Connecting the Dots: Sintering of Liquid Metal Particles for Soft and Stretchable Conductors. Chem Rev 2025; 125:3551-3585. [PMID: 40036064 DOI: 10.1021/acs.chemrev.4c00850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2025]
Abstract
This review focuses on the sintering of liquid metal particles (LMPs). Here, sintering means the partial merging or connecting of particles (or droplets) to form a network of percolated and, thus, conductive electrical pathways. LMPs are attractive materials because they can be suspended in a carrier fluid to create printable inks or distributed in an elastomer to create soft, stretchable composites. However, films and traces of LMPs are not typically conductive as fabricated due to the native oxide that forms on the surface of the particles. In the case of composites, polymers can also get between particles, making sintering more challenging. Sintering can be done via a variety of ways, such as mechanical, thermal, and chemical processing. This review discusses the mechanisms to sinter these particles, patterning techniques that use sintering, unique properties of sintered LMPs, and their practical applications in fields such as stretchable electronics, soft robotics, and active materials.
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Affiliation(s)
- Simok Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Syed Ahmed Jaseem
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Nurit Atar
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Meixiang Wang
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
- Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, P. R. China
| | - Jeong Yong Kim
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Mohammadreza Zare
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Sooyoung Kim
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
| | - Michael D Bartlett
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, Virginia 24061, United States
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Jae-Woong Jeong
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- KAIST Institute for Health Science and Technology, Daejeon 34141, Republic of Korea
- KAIST Institute for NanoCentury, Daejeon 34141, Republic of Korea
| | - Michael D Dickey
- Department of Chemical and Biomolecular Engineering, North Carolina State University (NCSU), Raleigh, North Carolina 27606, United States
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3
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Lin Z, Luo M, Liang J, Li Z, Lin Y, Chen X, Chen B, Peng L, Ouyang Y, Mou L. A liquid metal-based sticky conductor for wearable and real-time electromyogram monitoring with machine learning classification. J Mater Chem B 2025; 13:3906-3917. [PMID: 40007317 DOI: 10.1039/d4tb01711k] [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: 02/27/2025]
Abstract
Skin electronics face challenges related to the interface between rigid and soft materials, resulting in discomfort and signal inaccuracies. This study presents the development and characterization of a liquid metal-polydimethylsiloxane (LM-PDMS) sticky conductor designed for wearable electromyography (EMG) monitoring. The conductor leverages a composite of LM inks and PDMS, augmented with silver nanowires (AgNWs) and surface-modified with mercaptoundecanoic acid (MUD) to enhance conductivity. The mechanical properties of the PDMS matrix were optimized using Triton-X to achieve a flexible and adhesive configuration suitable for skin contact. Our LM-PDMS sticky conductor demonstrated excellent stretchability, could endure up to 300% strain without damage, and maintained strong adherence to the skin without relative displacement. Biocompatibility tests confirmed high cell viability, making it suitable for long-term use. EMG signal analysis revealed reliable muscle activity detection, with advanced signal processing techniques effectively filtering noise and stabilizing the baseline. Furthermore, we employed machine learning algorithms to classify EMG signals, achieving high accuracy in distinguishing different muscle activities. This study showcases the potential of LM-PDMS sticky conductors for advanced wearable bioelectronics, offering promising applications in personalized healthcare and real-time muscle activity monitoring.
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Affiliation(s)
- Zixin Lin
- The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Yanjiang Road, Yuexiu District, Guangzhou, Guangdong 510120, P. R. China.
| | - Mingmei Luo
- The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Yanjiang Road, Yuexiu District, Guangzhou, Guangdong 510120, P. R. China.
| | - Jiayi Liang
- The Fifth Affiliated Hospital of Guangzhou Medical University, Department of Biotechnology, GMU-GIBH Joint School of Life Science, Guangzhou Medical University, Guangzhou, 511436, P. R. China.
| | - Zijie Li
- The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Yanjiang Road, Yuexiu District, Guangzhou, Guangdong 510120, P. R. China.
| | - Yanting Lin
- The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Yanjiang Road, Yuexiu District, Guangzhou, Guangdong 510120, P. R. China.
| | - Xiaman Chen
- The Fifth Affiliated Hospital of Guangzhou Medical University, Department of Biotechnology, GMU-GIBH Joint School of Life Science, Guangzhou Medical University, Guangzhou, 511436, P. R. China.
| | - Baozhu Chen
- The Fifth Affiliated Hospital of Guangzhou Medical University, Department of Biotechnology, GMU-GIBH Joint School of Life Science, Guangzhou Medical University, Guangzhou, 511436, P. R. China.
| | - Liang Peng
- The Fifth Affiliated Hospital of Guangzhou Medical University, Department of Biotechnology, GMU-GIBH Joint School of Life Science, Guangzhou Medical University, Guangzhou, 511436, P. R. China.
| | - Yongchang Ouyang
- The Fifth Affiliated Hospital of Guangzhou Medical University, Department of Biotechnology, GMU-GIBH Joint School of Life Science, Guangzhou Medical University, Guangzhou, 511436, P. R. China.
| | - Lei Mou
- The Key Laboratory of Advanced Interdisciplinary Studies, The First Affiliated Hospital of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Yanjiang Road, Yuexiu District, Guangzhou, Guangdong 510120, P. R. China.
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4
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Zhu L, Zhou X, Zhang J, Xia Y, Wu M, Zhang Y, Lu Z, Li W, Liu L, Liu H, Yu J, Xiong J. Self-Adhesive Elastic Conductive Ink with High Permeability and Low Diffusivity for Direct Printing of Universal Textile Electronics. ACS NANO 2024; 18:34750-34762. [PMID: 39670287 DOI: 10.1021/acsnano.4c11291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2024]
Abstract
Elastic conductive ink (ECI) can effectively balance the electromechanical properties of printed flexible electronics. It remains challenging to realize ECIs for direct printing on deformable porous substrates with complex textures, such as textiles, to form continuous and stable electrical paths. We engineered a self-adhesive ECI with high permeability and low diffusivity, achieving efficient electrode printing on a wide range of textiles with material and structure diversity. The ECI consists of a microphase separation-toughened elastomer (styrene-isoprene-styrene/ethyl vinyl acetate (SIS-EVA)) and a binary conductive filler. SIS-EVA provides a tough framework to protect silver flakes (AgFKs) and forms a ductile conductive path, which can be electrically compensated by liquid metal microspheres (LMMSs) upon dynamic deformation. The freestanding ECI conductor demonstrates a breaking strain of ∼1305.5% and a conductivity of ∼5322.7 S cm-1. The ECI can be universally printed on diversified textiles free of pretreatment, with high permeability (319.2 μm) and low diffusivity (6.2 μm), demonstrating a stable printing line width of ∼216 μm on knitted cotton textiles, while maintaining electrical stability after 200 stretching cycles with 50% strain. Printed electronic textiles with stretchability, high abrasion resistance, and machine washability are demonstrated for wearable applications such as fabric electrodes, capacitive sensors, and electrocardiograph monitoring.
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Affiliation(s)
- Liming Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Xinran Zhou
- Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, China
| | - Jiwei Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Yong Xia
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Mengjie Wu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Yue Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Zeren Lu
- College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Weikang Li
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Luyun Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Hao Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
| | - Jianyong Yu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
- Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, China
| | - Jiaqing Xiong
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Textiles, Donghua University, Shanghai 201620, China
- Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, China
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5
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Muhammed Ajmal C, Jeong J, Cheon S, Majee MK, Yang H, Baik S. Absence of Additional Stretching-Induced Electron Scattering in Highly Conductive Cross-linked Nanocomposites with Negligible Tunneling Barrier Height and Width. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2409337. [PMID: 39467158 DOI: 10.1002/advs.202409337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 10/14/2024] [Indexed: 10/30/2024]
Abstract
The intrinsic resistance of stretchable materials is dependent on strain, following Ohm's law. Here the invariable resistance of highly conductive cross-linked nanocomposites over 53% strain is reported, where additional electron scattering is absent with stretching. The in situ generated uniformly dispersed small silver nanosatellite particles (diameter = 3.6 nm) realize a short tunneling barrier width of 4.1 nm in cross-linked silicone rubber matrix. Furthermore, the barrier height can be precisely controlled by the gap state energy level modulation in silicone rubber using cross-linkers. The negligible barrier height (0.01 eV) and short barrier width, achieved by the silver nanosatellite particles in cross-linked silicone rubber, dramatically increase the electrical conductivity (51 710 S cm-1) by more than 4 orders of magnitude. The high conductance is also maintained over 53% strain. The quantum tunneling behavior is observed when the barrier height is increased, following the Simmons approximation theory. The transport becomes diffusive, following Ohm's law, when the barrier width is increased beyond 10.3 nm. This study provides a novel strain-invariant resistance mechanism in highly conductive cross-linked nanocomposites.
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Affiliation(s)
- C Muhammed Ajmal
- Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Juyeong Jeong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seongsu Cheon
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - M K Majee
- Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Seunghyun Baik
- Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- School of Mechanical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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6
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Woodman SJ, Shah DS, Landesberg M, Agrawala A, Kramer-Bottiglio R. Stretchable Arduinos embedded in soft robots. Sci Robot 2024; 9:eadn6844. [PMID: 39259780 DOI: 10.1126/scirobotics.adn6844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 08/12/2024] [Indexed: 09/13/2024]
Abstract
To achieve real-world functionality, robots must have the ability to carry out decision-making computations. However, soft robots stretch and therefore need a solution other than rigid computers. Examples of embedding computing capacity into soft robots currently include appending rigid printed circuit boards to the robot, integrating soft logic gates, and exploiting material responses for material-embedded computation. Although promising, these approaches introduce limitations such as rigidity, tethers, or low logic gate density. The field of stretchable electronics has sought to solve these challenges, but a complete pipeline for direct integration of single-board computers, microcontrollers, and other complex circuitry into soft robots has remained elusive. We present a generalized method to translate any complex two-layer circuit into a soft, stretchable form. This enabled the creation of stretchable single-board microcontrollers (including Arduinos) and other commercial circuits (including SparkFun circuits), without design simplifications. As demonstrations of the method's utility, we embedded highly stretchable (>300% strain) Arduino Pro Minis into the bodies of multiple soft robots. This makes use of otherwise inert structural material, fulfilling the promise of the stretchable electronic field to integrate state-of-the-art computational power into robust, stretchable systems during active use.
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Affiliation(s)
- Stephanie J Woodman
- Department of Mechanical Engineering and Materials Science, Yale University, 9 Hillhouse Ave., New Haven, CT 06511, USA
| | - Dylan S Shah
- Department of Mechanical Engineering and Materials Science, Yale University, 9 Hillhouse Ave., New Haven, CT 06511, USA
| | - Melanie Landesberg
- Department of Mechanical Engineering and Materials Science, Yale University, 9 Hillhouse Ave., New Haven, CT 06511, USA
| | - Anjali Agrawala
- Department of Mechanical Engineering and Materials Science, Yale University, 9 Hillhouse Ave., New Haven, CT 06511, USA
| | - Rebecca Kramer-Bottiglio
- Department of Mechanical Engineering and Materials Science, Yale University, 9 Hillhouse Ave., New Haven, CT 06511, USA
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7
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Lin Y, Wang H, Qiu W, Ye C, Kong D. Liquid Metal-Based Self-Healing Conductors for Flexible and Stretchable Electronics. ACS APPLIED MATERIALS & INTERFACES 2024; 16:43083-43092. [PMID: 39115969 DOI: 10.1021/acsami.4c10541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Flexible and stretchable electronics rely on compliant conductors as essential building materials. However, these materials are susceptible to wear and tear, leading to degradation over time. In response to this concern, self-healing conductors have been developed to prolong the lifespan of functional devices. These conductors can autonomously restore their properties following damage. Conventional self-healing conductors typically comprise solid conductive fillers and healing agents dispersed within polymer matrices. However, the solid additives increase the stiffness and reduce the stretchability of the resulting composites. There is growing interest in utilizing gallium-based liquid metal alloys due to their exceptional electrical conductivity and liquid-phase deformability. These liquid metals are considered attractive candidates for developing compliant conductors capable of automatic recovery. This perspective delves into the rapidly advancing field of liquid metal-based self-healing conductors, exploring their design, fabrication, and critical applications. Furthermore, this article also addresses the current challenges and future directions in this active area of research.
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Affiliation(s)
- Yong Lin
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Hao Wang
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Weijie Qiu
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Chenyang Ye
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Desheng Kong
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
- Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
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8
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Li Y, Veronica A, Ma J, Nyein HYY. Materials, Structure, and Interface of Stretchable Interconnects for Wearable Bioelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2408456. [PMID: 39139019 DOI: 10.1002/adma.202408456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 07/24/2024] [Indexed: 08/15/2024]
Abstract
Since wearable technologies for telemedicine have emerged to tackle global health concerns, the demand for well-attested wearable healthcare devices with high user comfort also arises. Skin-wearables for health monitoring require mechanical flexibility and stretchability for not only high compatibility with the skin's dynamic nature but also a robust collection of fine health signals from within. Stretchable electrical interconnects, which determine the device's overall integrity, are one of the fundamental units being understated in wearable bioelectronics. In this review, a broad class of materials and engineering methodologies recently researched and developed are presented, and their respective attributes, limitations, and opportunities in designing stretchable interconnects for wearable bioelectronics are offered. Specifically, the electrical and mechanical characteristics of various materials (metals, polymers, carbons, and their composites) are highlighted, along with their compatibility with diverse geometric configurations. Detailed insights into fabrication techniques that are compatible with soft substrates are also provided. Importantly, successful examples of establishing reliable interfacial connections between soft and rigid elements using novel interconnects are reviewed. Lastly, some perspectives and prospects of remaining research challenges and potential pathways for practical utilization of interconnects in wearables are laid out.
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Affiliation(s)
- Yue Li
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, 00000, China
| | - Asmita Veronica
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, 00000, China
| | - Jiahao Ma
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, 00000, China
| | - Hnin Yin Yin Nyein
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, 00000, China
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9
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Krisnadi F, Kim S, Im S, Chacko D, Vong MH, Rykaczewski K, Park S, Dickey MD. Printable Liquid Metal Foams That Grow When Watered. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308862. [PMID: 38252810 DOI: 10.1002/adma.202308862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/30/2023] [Indexed: 01/24/2024]
Abstract
Pastes and "foams" containing liquid metal (LM) as the continuous phase (liquid metal foams, LMFs) exhibit metallic properties while displaying paste or putty-like rheological behavior. These properties enable LMFs to be patterned into soft and stretchable electrical and thermal conductors through processes conducted at room temperature, such as printing. The simplest LMFs, featured in this work, are made by stirring LM in air, thereby entraining oxide-lined air "pockets" into the LM. Here, it is reported that mixing small amounts of water (as low as 1 wt%) into such LMFs gives rise to significant foaming by harnessing known reactions that evolve hydrogen and produce oxides. The resulting structures can be ≈4-5× their original volume and possess a fascinating combination of attributes: porosity, electrical conductivity, and responsiveness to environmental conditions. This expansion can be utilized for a type of 4D printing in which patterned conductors "grow," fill cavities, and change shape and density with respect to time. Excessive exposure to water in the long term ultimately consumes the metal in the LMF. However, when exposure to water is controlled, the metallic properties of porous LMFs can be preserved.
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Affiliation(s)
- Febby Krisnadi
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Seoyeon Kim
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, South Korea
| | - Sooik Im
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dennis Chacko
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Man Hou Vong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Konrad Rykaczewski
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Sungjune Park
- School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Michael D Dickey
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA
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10
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Wu D, Wu S, Narongdej P, Duan S, Chen C, Yan Y, Liu Z, Hong W, Frenkel I, He X. Fast and Facile Liquid Metal Printing via Projection Lithography for Highly Stretchable Electronic Circuits. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2307632. [PMID: 38126914 DOI: 10.1002/adma.202307632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 12/19/2023] [Indexed: 12/23/2023]
Abstract
Soft electronic circuits are crucial for wearable electronics, biomedical technologies, and soft robotics, requiring soft conductive materials with high conductivity, high strain limit, and stable electrical performance under deformation. Liquid metals (LMs) have become attractive candidates with high conductivity and fluidic compliance, while effective manufacturing methods are demanded. Digital light processing (DLP)-based projection lithography is a high-resolution and high-throughput printing technique for primarily polymers and some metals. If LMs can be printed with DLP as well, the entire soft devices can be fabricated by one printer in a streamlined and highly efficient process. Herein, fast and facile DLP-based LM printing is achieved. Simply with 5-10 s of patterned ultraviolet (UV)-light exposure, a highly conductive and stretchable pattern can be printed using a photo-crosslinkable LM particle ink. The printed eutectic gallium indium traces feature high resolution (≈20 µm), conductivity (3 × 106 S m-1), stretchability (≈2500%), and excellent stability (consistent performance at different deformation). Various patterns are printed in diverse material systems for broad applications including stretchable displays, epidermal strain sensors, heaters, humidity sensors, conformal electrodes for electrography, and multi-layer actuators. The facile and scalable process, excellent performance, and diverse applications ensure its broad impact on soft electronic manufacturing.
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Affiliation(s)
- Dong Wu
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Poom Narongdej
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Sidi Duan
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Chi Chen
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Yichen Yan
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Zixiao Liu
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Wen Hong
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Imri Frenkel
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
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11
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Bian Y, Shi H, Yuan Q, Zhu Y, Lin Z, Zhuang L, Han X, Wang P, Chen M, Wang X. Patterning Techniques Based on Metallized Electrospun Nanofibers for Advanced Stretchable Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309735. [PMID: 38687841 PMCID: PMC11234419 DOI: 10.1002/advs.202309735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/14/2024] [Indexed: 05/02/2024]
Abstract
Stretchable electronics have experienced remarkable progress, especially in sensors and wireless communication systems, attributed to their ability to conformably contact with rough or uneven surfaces. However, the development of complex, multifunctional, and high-precision stretchable electronics faces substantial challenges, including instability at rigid-soft interfaces and incompatibility with traditional high-precision patterning technologies. Metallized electrospun nanofibers emerge as a promising conductive filler, offering exceptional stretchability, electrical conductivity, transparency, and compatibility with existing patterning technologies. Here, this review focuses on the fundamental properties, preparation processes, patterning technologies, and application scenarios of conductive stretchable composites based on metallized nanofibers. Initially, it introduces the fabrication processes of metallized electrospun nanofibers and their advantages over alternative materials. It then highlights recent progress in patterning technologies, including collector collection, vapor deposition with masks, and lithography, emphasizing their role in enhancing precision and integration. Furthermore, the review shows the broad applicability and potential influence of metallized electrospun nanofibers in various fields through their use in sensors, wireless systems, semiconductor devices, and intelligent healthcare solutions. Ultimately, this review seeks to spark further innovation and address the prevailing challenges in stretchable electronics, paving the way for future breakthroughs in this dynamic field.
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Affiliation(s)
- Yuhan Bian
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Haozhou Shi
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Qunchen Yuan
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yuxuan Zhu
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Zhengzi Lin
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Liujing Zhuang
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Xun Han
- ZJU-Hangzhou Global Scientific and Technological Innovation Center School of Micro-Nano Electronics, Zhejiang University, Hangzhou, 311200, P. R. China
| | - Ping Wang
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Mengxiao Chen
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
- Research Center for Humanoid Sensing, Zhejiang Lab, Hangzhou, 311121, P. R. China
| | - Xiandi Wang
- Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Education Ministry, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, 310027, P. R. China
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12
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Parvini E, Hajalilou A, Gonçalves Vilarinho JP, Alhais Lopes P, Maranha M, Tavakoli M. Gallium-Carbon: A Universal Composite for Sustainable 3D Printing of Integrated Sensor-Heater-Battery Systems in Wearable and Recyclable Electronics. ACS APPLIED MATERIALS & INTERFACES 2024; 16:32812-32823. [PMID: 38878000 PMCID: PMC11212025 DOI: 10.1021/acsami.4c02706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/19/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024]
Abstract
This study presents a novel three-dimensional (3D) printable gallium-carbon black-styrene isoprene styrene block copolymer (Ga-CB-SIS), offering a versatile solution for the rapid fabrication of stretchable and integrated sensor-heater-battery systems in wearable and recyclable electronics. The composite exhibits sinter-free characteristics, allowing for printing on various substrates, including heat-sensitive materials. Unlike traditional conductive inks, the Ga-CB-SIS composite, composed of gallium, carbon black, and styrene isoprene block copolymers, combines electrical conductivity, stretchability, and digital printability. By introducing carbon black as a filler material, the composite achieves promising electromechanical behavior, making it suitable for low-resistance heaters, batteries, and electrical interconnects. The fabrication process involves a simultaneous mixing and ball-milling technique, resulting in a homogeneous composition with a CB/Ga ratio of 4.3%. The Ga-CB-SIS composite showcases remarkable adaptability for digital printing on various substrates. Its self-healing property and efficient recycling technique using a deep eutectic solvent contribute to an environmentally conscious approach to electronic waste, with a high gallium recovery efficiency of ∼98%. The study's innovation extends to applications, presenting a fully digitally printed stretchable Ga-CB-SIS battery integrated with strain sensors and heaters, representing a significant leap in LM-based composites. This multifunctional and sustainable Ga-CB-SIS composite emerges as a key player in the future of wearable electronics, offering integrated circuits with sensing, heating, and energy storage elements.
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Affiliation(s)
- Elahe Parvini
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
| | - Abdollah Hajalilou
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
| | - João Pedro Gonçalves Vilarinho
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
| | - Pedro Alhais Lopes
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
| | - Miguel Maranha
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
| | - Mahmoud Tavakoli
- Soft and Printed Microelectronics
Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra 3030-290, Portugal
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13
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Vazquez R, Motovilova E, Winkler SA. Stretchable Sensor Materials Applicable to Radiofrequency Coil Design in Magnetic Resonance Imaging: A Review. SENSORS (BASEL, SWITZERLAND) 2024; 24:3390. [PMID: 38894182 PMCID: PMC11174967 DOI: 10.3390/s24113390] [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: 03/14/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
Wearable sensors are rapidly gaining influence in the diagnostics, monitoring, and treatment of disease, thereby improving patient outcomes. In this review, we aim to explore how these advances can be applied to magnetic resonance imaging (MRI). We begin by (i) introducing limitations in current flexible/stretchable RF coils and then move to the broader field of flexible sensor technology to identify translatable technologies. To this goal, we discuss (ii) emerging materials currently used for sensor substrates, (iii) stretchable conductive materials, (iv) pairing and matching of conductors with substrates, and (v) implementation of lumped elements such as capacitors. Applicable (vi) fabrication methods are presented, and the review concludes with a brief commentary on (vii) the implementation of the discussed sensor technologies in MRI coil applications. The main takeaway of our research is that a large body of work has led to exciting new sensor innovations allowing for stretchable wearables, but further exploration of materials and manufacturing techniques remains necessary, especially when applied to MRI diagnostics.
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Affiliation(s)
- Rigoberto Vazquez
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 10065, USA
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | | | - Simone Angela Winkler
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 10065, USA
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
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14
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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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15
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Li X, Hou K, Long Y, Song K. LM-Gel Plasticine Based on Binary Cooperative with Kneadable Shaping and Conductivity. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38711229 DOI: 10.1021/acsami.4c03471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Liquid metal (LM)-based polymers have received growing interest for wearable health monitoring, electronic skins, and soft robotics. However, fabricating multifunctional LM-based polymers, in particular, featuring a convenient shaping ability while offering excellent deformability and conductivity remains a challenge. To overcome this obstacle, here, we propose a strategy to prepare LM-Gel "plasticine" (LGP) with great deformability, which is composed of a PVA (poly(vinyl alcohol)) soft network and an LM conductive phase. LGP can be easily constructed into different shapes such as plasticine and can be applied to different conditions (such as building a 3D circuit, circuit repair, and switch). Meanwhile, LGP has great conductivity (2.3 × 104 S/m) after surface annealing. Besides, LGP has a good electric heating performance, which shows the potential for application in wearable heating devices. Thus, this approach not only provides a way to prepare LM-polymer plasticine but also provides a novel perspective toward extending the applied range of LM-polymer composites.
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Affiliation(s)
- Xingchao Li
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Kai Hou
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yue Long
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- Binzhou Institute of Technology, Weiqiao-UCAS Science and Technology Park, Binzhou City 256606, Shandong, P. R. China
| | - Kai Song
- Key Laboratory of Bio-Inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- Binzhou Institute of Technology, Weiqiao-UCAS Science and Technology Park, Binzhou City 256606, Shandong, P. R. China
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16
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Freitas MC, Sanati AL, Lopes PA, Silva AF, Tavakoli M. 3D Printed Gallium Battery with Outstanding Energy Storage: Toward Fully Printed Battery-on-the-Board Soft Electronics. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304716. [PMID: 38335309 DOI: 10.1002/smll.202304716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/25/2023] [Indexed: 02/12/2024]
Abstract
The last decade observed rapid progress in soft electronics. Yet, the ultimate desired goal for many research fields is to fabricate fully integrated soft-matter electronics with sensors, interconnects, and batteries, at the ease of pushing a print button. In this work, an important step is taken toward this by demonstrating an ultra-stretchable thin-film Silver-Gallium (Ag-Ga) battery with an unprecedented combination of areal capacity and mechanical strain tolerance. The Biphasic Gallium-Carbon anode electrode demonstrates a record-breaking areal capacity of 78.7 mAh cm-2, and an exceptional stretchability of 170%, showing clear progress over state-of-the-art. The exceptional theoretical capacity of gallium, along with its natural liquid phase self-healing, and its dendrite-free operation permits excellent electromechanical cycling. All composites of the battery including liquid-metal-based current collectors, and electrodes are sinter-free and digitally printable at room temperature, enabling the use of a wide range of substrates, including heat-sensitive polymer films. Consequently, it is demonstrated for the first time multi-layer, and multi-material digital printing of complex battery-on-the-board stretchable devices that integrate printed sensor, multiple cells of printed battery, highly conductive interconnects, and silicone chips, and demonstrate a tailor-made patch for body-worn electrophysiological monitoring.
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Affiliation(s)
- Marta Calisto Freitas
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-790, Portugal
| | - Afsaneh L Sanati
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-790, Portugal
| | - Pedro Alhais Lopes
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-790, Portugal
| | - André F Silva
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-790, Portugal
| | - Mahmoud Tavakoli
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-790, Portugal
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17
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Zu W, Carranza HE, Bartlett MD. Enhancing Electrical Conductivity of Stretchable Liquid Metal-Silver Composites through Direct Ink Writing. ACS APPLIED MATERIALS & INTERFACES 2024; 16. [PMID: 38685822 PMCID: PMC11082841 DOI: 10.1021/acsami.4c02466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/11/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
Structure-property-process relationships are a controlling factor in the performance of materials. This offers opportunities in emerging areas, such as stretchable conductors, to control process conditions during printing to enhance performance. Herein, by systematically tuning direct ink write (DIW) process parameters, the electrical conductivity of multiphase liquid metal (LM)-silver stretchable conductors is increased by a maximum of 400% to over 1.06 × 106 S·m-1. This is achieved by modulating the DIW print velocity, which enables the in situ elongation, coalescence, and percolation of these multiphase inclusions during printing. These DIW printed filaments are conductive as fabricated and are soft (modulus as low as 1.1 MPa), stretchable (strain limit >800%), and show strain invariant conductivity up to 80% strain. These capabilities are demonstrated through a set of electromagnetic induction coils that can transfer power wirelessly through air and water, even under deformation. This work provides a methodology to program properties in stretchable conductors, where the combination of material composition and process parameters leads to greatly enhanced performance. This approach can find use in applications such as soft robots, soft electronics, and printed materials for deformable, yet highly functional devices.
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Affiliation(s)
- Wuzhou Zu
- Mechanical
Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Hugo E. Carranza
- Mechanical
Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Michael D. Bartlett
- Mechanical
Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, Virginia 24061, United States
- Macromolecules
Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
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18
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Shukla D, Wang H, Awartani O, Dickey MD, Zhu Y. Surface Embedded Metal Nanowire-Liquid Metal-Elastomer Hybrid Composites for Stretchable Electronics. ACS APPLIED MATERIALS & INTERFACES 2024; 16:14183-14197. [PMID: 38457372 DOI: 10.1021/acsami.4c00318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2024]
Abstract
Both liquid metal (LM) and metallic filler-based conductive composites are promising stretchable conductors. LM alloys exhibit intrinsically high deformability but present challenges for patterning on polymeric substrates due to high surface tension. On the other hand, conductive composites comprising metallic fillers undergo considerable decrease in electrical conductivity under mechanical deformation. To address the challenges, we present silver nanowire (AgNW)-LM-elastomer hybrid composite films, where AgNWs and LM are embedded below the surface of an elastomeric matrix, using two fabrication approaches, sequential and mixed. We investigate and understand the process-structure-property relationship of the AgNW-LM-elastomer hybrid composites fabricated using two approaches. Different weight ratios of AgNWs and LM particles provide tunable electrical conductivity. The hybrid composites show more stable electromechanical performance than the composites with AgNWs alone. In particular, 1:2.4 (AgNW:LMP w/w) sequential hybrid composite shows electromechanical stability similar to that of the LM-elastomer composite, with a resistance increase of 2.04% at 90% strain. The sequential approach is found to form AgIn2 intermetallic compounds which along with Ga-In bonds, imparts large deformability to the sequential hybrid composite as well as mechanical robustness against scratching, cutting, peeling, and wiping. To demonstrate the application of the hybrid composite for stretchable electronics, a laser patterned stretchable heater on textile and a stretchable circuit including a light-emitting diode are fabricated.
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Affiliation(s)
- Darpan Shukla
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Hongyu Wang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Omar Awartani
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Michael D Dickey
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Yong Zhu
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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19
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Lu G, Ni E, Jiang Y, Wu W, Li H. Room-Temperature Liquid Metals for Flexible Electronic Devices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304147. [PMID: 37875665 DOI: 10.1002/smll.202304147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/26/2023] [Indexed: 10/26/2023]
Abstract
Room-temperature gallium-based liquid metals (RT-GaLMs) have garnered significant interest recently owing to their extraordinary combination of fluidity, conductivity, stretchability, self-healing performance, and biocompatibility. They are ideal materials for the manufacture of flexible electronics. By changing the composition and oxidation of RT-GaLMs, physicochemical characteristics of the liquid metal can be adjusted, especially the regulation of rheological, wetting, and adhesion properties. This review highlights the advancements in the liquid metals used in flexible electronics. Meanwhile related characteristics of RT-GaLMs and underlying principles governing their processing and applications for flexible electronics are elucidated. Finally, the diverse applications of RT-GaLMs in self-healing circuits, flexible sensors, energy harvesting devices, and epidermal electronics, are explored. Additionally, the challenges hindering the progress of RT-GaLMs are discussed, while proposing future research directions and potential applications in this emerging field. By presenting a concise and critical analysis, this paper contributes to the advancement of RT-GaLMs as an advanced material applicable for the new generation of flexible electronics.
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Affiliation(s)
- Guixuan Lu
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Erli Ni
- The Institute for Advanced Studies of Wuhan University, Wuhan University, Wuhan, Hubei, 430072, China
| | - Yanyan Jiang
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Weikang Wu
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
| | - Hui Li
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, Shandong, 250061, China
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20
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Sakorikar T, Mihaliak N, Krisnadi F, Ma J, Kim TI, Kong M, Awartani O, Dickey MD. A Guide to Printed Stretchable Conductors. Chem Rev 2024; 124:860-888. [PMID: 38291556 DOI: 10.1021/acs.chemrev.3c00569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Printing of stretchable conductors enables the fabrication and rapid prototyping of stretchable electronic devices. For such applications, there are often specific process and material requirements such as print resolution, maximum strain, and electrical/ionic conductivity. This review highlights common printing methods and compatible inks that produce stretchable conductors. The review compares the capabilities, benefits, and limitations of each approach to help guide the selection of a suitable process and ink for an intended application. We also discuss methods to design and fabricate ink composites with the desired material properties (e.g., electrical conductance, viscosity, printability). This guide should help inform ongoing and future efforts to create soft, stretchable electronic devices for wearables, soft robots, e-skins, and sensors.
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Affiliation(s)
- Tushar Sakorikar
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Nikolas Mihaliak
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Febby Krisnadi
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jinwoo Ma
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Tae-Il Kim
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon, Gyeonggi 16419, South Korea
| | - Minsik Kong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Omar Awartani
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Michael D Dickey
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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21
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Wajahat M, Kim JH, Kim JH, Jung ID, Pyo J, Seol SK. 4D Printing of Ultrastretchable Magnetoactive Soft Material Architectures for Soft Actuators. ACS APPLIED MATERIALS & INTERFACES 2023; 15:59582-59591. [PMID: 38100363 DOI: 10.1021/acsami.3c12173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Magnetoactive soft materials (MSMs) comprising magnetic particles and soft matrices have emerged as smart materials for realizing soft actuators. 4D printing, which involves fabricating 3D architectures that can transform shapes under external magnetic fields, is an effective way to fabricate MSMs-based soft actuators with complex shapes. The printed MSMs must be flexible, stretchable, and adaptable in their magnetization profiles to maximize the degrees of freedom for shape morphing. This study utilizes a facile 4D printing strategy for producing ultrastretchable (stretchability > 1000%) MSM 3D architectures for soft-actuator applications. The strategy involves two sequential steps: (i) direct ink writing (DIW) of the MSM 3D architectures with ink composed of NdFeB and styrene-isoprene block copolymers (SIS) at room temperature and (ii) programming and reconfiguration of the magnetization profiles of the printed architecture using an origami-inspired magnetization method (magnetization field, Hm = 2.7 T). Various differently shaped MSM 3D architectures, which can be transformed into desired shapes under an actuation magnetic field (Ba = 85 mT), are successfully fabricated. In addition, two different soft-actuator applications are demonstrated: a multifinger magnetic soft gripper and a Kirigami-shaped 3D electrical switch with conductive and magnetic functionalities. Our strategy shows potential for realizing multifunctional, shape-morphing, and reprogrammable magnetoactive devices for advanced soft-actuator applications.
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Affiliation(s)
- Muhammad Wajahat
- Smart 3D Printing Research Team, Korea Electrotechnology Research Institute (KERI), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
| | - Je Hyeong Kim
- Smart 3D Printing Research Team, Korea Electrotechnology Research Institute (KERI), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
| | - Jung Hyun Kim
- Smart 3D Printing Research Team, Korea Electrotechnology Research Institute (KERI), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
| | - Im Doo Jung
- Department of Mechanical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulju-gun, Ulsangwang-yeogsi, Ulsan 44919, Republic of Korea
| | - Jaeyeon Pyo
- Smart 3D Printing Research Team, Korea Electrotechnology Research Institute (KERI), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
| | - Seung Kwon Seol
- Smart 3D Printing Research Team, Korea Electrotechnology Research Institute (KERI), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
- Electro-Functional Materials Engineering, University of Science and Technology (UST), Changwon-si, Gyeongsangnam-do 51543, Republic of Korea
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22
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Lin Y, Fang T, Bai C, Sun Y, Yang C, Hu G, Guo H, Qiu W, Huang W, Wang L, Tao Z, Lu YQ, Kong D. Ultrastretchable Electrically Self-Healing Conductors Based on Silver Nanowire/Liquid Metal Microcapsule Nanocomposites. NANO LETTERS 2023. [PMID: 38047765 DOI: 10.1021/acs.nanolett.3c03670] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Stretchable conductive nanocomposites are essential for deformable electronic devices. These conductors currently face significant limitations, such as insufficient deformability, significant resistance changes upon stretching, and drifted properties during cyclic deformations. To tackle these challenges, we present an electrically self-healing and ultrastretchable conductor in the form of bilayer silver nanowire/liquid metal microcapsule nanocomposites. These nanocomposites utilize silver nanowires to establish their initial excellent conductivity. When the silver nanowire networks crack during stretching, the microcapsules are ruptured to release the encased liquid metal for recovering the electrical properties. This self-healing capability allows the nanocomposite to achieve ultrahigh stretchability for both uniaxial and biaxial strains, minor changes in resistance during stretching, and stable resistance after repetitive deformations. The conductors have been used to create skin-attachable electronic patches and stretchable light-emitting diode arrays with enhanced robustness. These developments provide a bioinspired strategy to enhance the performance and durability of conductive nanocomposites.
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Affiliation(s)
- Yong Lin
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Ting Fang
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Chong Bai
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Yuping Sun
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Cheng Yang
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Gaohua Hu
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Haorun Guo
- College of Chemical Engineering and Technology, Engineering Research Center of Seawater Utilization Technology of Ministry of Education, State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, China
| | - Weijie Qiu
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Weixi Huang
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Lin Wang
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
| | - Zihao Tao
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Yan-Qing Lu
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Desheng Kong
- College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210023, China
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23
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Zhou J, Zhao S, Tang L, Zhang D, Sheng B. Programmable and Weldable Superelastic EGaIn/TPU Composite Fiber by Wet Spinning for Flexible Electronics. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 38031357 DOI: 10.1021/acsami.3c11068] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
As an essential component of flexible electronics, superelastic conductive fibers with good mechanical and electrical properties have drawn significant attention, especially in their preparation. In this study, we prepared a superelastic conductive fiber composed of eutectic gallium-indium (EGaIn) and thermoplastic polyurethane (TPU) by simple wet spinning. The composite conductive fiber with a liquid metal (LM) content of 85 wt % achieved a maximum strain at a break of 659.2%, and after the conductive pathway in the porous structure of the composite fibers was fully activated, high conductivity (1.2 × 105 S/m) was achieved with 95 wt % LM by mechanical sintering and training processes. The prepared conductive fibers exhibited a stable resistive response as the fibers were strained and could be sewn into fabrics and used as wearable strain sensors to monitor various human motions. These conductive fibers can be molded into helical by heating, and they have excellent electrical properties at a maximum mechanical strain of 3400% (resistance change <0.27%) with a helical index of 11. Moreover, the conductive fibers can be welded to various two or three-dimensional conductors. In summary, with a scalable manufacturing process, weldability, superelasticity, and high electrical conductivity, EGaIn/TPU composite fibers fabricated by wet spinning have considerable potential for flexible electronics.
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Affiliation(s)
- Jingyu Zhou
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Shanghai Key Laboratory of Modern Optical Systems, Engineering Research Center of Optical Instruments and Systems, Shanghai 200093, China
| | - Shanshan Zhao
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Shanghai Key Laboratory of Modern Optical Systems, Engineering Research Center of Optical Instruments and Systems, Shanghai 200093, China
| | - Lei Tang
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Shanghai Key Laboratory of Modern Optical Systems, Engineering Research Center of Optical Instruments and Systems, Shanghai 200093, China
| | - Dawei Zhang
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Shanghai Key Laboratory of Modern Optical Systems, Engineering Research Center of Optical Instruments and Systems, Shanghai 200093, China
| | - Bin Sheng
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
- Shanghai Key Laboratory of Modern Optical Systems, Engineering Research Center of Optical Instruments and Systems, Shanghai 200093, China
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24
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Reis Carneiro M, de Almeida AT, Tavakoli M, Majidi C. Recyclable Thin-Film Soft Electronics for Smart Packaging and E-Skins. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301673. [PMID: 37436091 PMCID: PMC10502858 DOI: 10.1002/advs.202301673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/12/2023] [Indexed: 07/13/2023]
Abstract
Despite advances in soft, sticker-like electronics, few efforts have dealt with the challenge of electronic waste. Here, this is addressed by introducing an eco-friendly conductive ink for thin-film circuitry composed of silver flakes and a water-based polyurethane dispersion. This ink uniquely combines high electrical conductivity (1.6 × 105 S m-1 ), high resolution digital printability, robust adhesion for microchip integration, mechanical resilience, and recyclability. Recycling is achieved with an ecologically-friendly processing method to decompose the circuits into constituent elements and recover the conductive ink with a decrease of only 2.4% in conductivity. Moreover, adding liquid metal enables stretchability of up to 200% strain, although this introduces the need for more complex recycling steps. Finally, on-skin electrophysiological monitoring biostickers along with a recyclable smart package with integrated sensors for monitoring safe storage of perishable foods are demonstrated.
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Affiliation(s)
- Manuel Reis Carneiro
- Soft Machines LabDepartment of Mechanical EngineeringCarnegie Mellon UniversityPittsburghPA15213USA
- Institute of Systems and RoboticsDepartment of Electrical and Computer EngineeringUniversity of CoimbraCoimbra3030‐290Portugal
| | - Aníbal T. de Almeida
- Institute of Systems and RoboticsDepartment of Electrical and Computer EngineeringUniversity of CoimbraCoimbra3030‐290Portugal
| | - Mahmoud Tavakoli
- Institute of Systems and RoboticsDepartment of Electrical and Computer EngineeringUniversity of CoimbraCoimbra3030‐290Portugal
| | - Carmel Majidi
- Soft Machines LabDepartment of Mechanical EngineeringCarnegie Mellon UniversityPittsburghPA15213USA
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25
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Vinciguerra MR, Patel DK, Zu W, Tavakoli M, Majidi C, Yao L. Multimaterial Printing of Liquid Crystal Elastomers with Integrated Stretchable Electronics. ACS APPLIED MATERIALS & INTERFACES 2023; 15:24777-24787. [PMID: 37163362 DOI: 10.1021/acsami.2c23028] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Liquid crystal elastomers (LCEs) have grown in popularity in recent years as a stimuli-responsive material for soft actuators and shape reconfigurable structures. To make these material systems electrically responsive, they must be integrated with soft conductive materials that match the compliance and deformability of the LCE. This study introduces a design and manufacturing methodology for combining direct ink write (DIW) 3D printing of soft, stretchable conductive inks with DIW-based "4D printing" of LCE to create fully integrated, electrically responsive, shape programmable matter. The conductive ink is composed of a soft thermoplastic elastomer, a liquid metal alloy (eutectic gallium indium, EGaIn), and silver flakes, exhibiting both high stretchability and conductivity (order of 105 S m-1). Empirical tuning of the LCE printing parameters gives rise to a smooth surface (<10 μm) for patterning the conductive ink with controlled trace dimensions. This multimaterial printing method is used to create shape reconfigurable LCE devices with on-demand circuit patterning that could otherwise not be easily fabricated through traditional means, such as an LCE bending actuator able to blink a Morse code signal and an LCE crawler with an on/off photoresistor controller. In contrast to existing fabrication methodologies, the inclusion of the conductive ink allows for stable power delivery to surface mount devices and Joule heating traces in a highly dynamic LCE system. This digital fabrication approach can be leveraged to push LCE actuators closer to becoming functional devices, such as shape programmable antennas and actuators with integrated sensing.
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Affiliation(s)
- Michael R Vinciguerra
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, United States
| | - Dinesh K Patel
- Human Computer Interaction Institute, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, United States
| | - Wuzhou Zu
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, United States
| | - Mahmoud Tavakoli
- Institute of Systems and Robotics, Department of Electrical Engineering, University of Coimbra, Coimbra 3090-290, Portugal
| | - Carmel Majidi
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, United States
| | - Lining Yao
- Human Computer Interaction Institute, Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, Pennsylvania 15213, United States
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26
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Ahmad A, Qurashi A, Sheehan D. Nano packaging – Progress and future perspectives for food safety, and sustainability. Food Packag Shelf Life 2023. [DOI: 10.1016/j.fpsl.2022.100997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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27
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Shim J, Kim YU, Kim YB, Ji SG, Kim YJ, Jo Y, Lee EJ, Yuk DG, Lee SY, Lee SS, Kim SK, Kim HS, Park JH, Jeong S. A Surface Conformal Laser-Assisted Alloying Reaction for 3D-Printable Solid/Liquid Biphasic Conductors. SMALL SCIENCE 2023; 3:2200089. [PMID: 40212058 PMCID: PMC11935982 DOI: 10.1002/smsc.202200089] [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: 11/10/2022] [Revised: 01/14/2023] [Indexed: 02/05/2023] Open
Abstract
Recently, electronics research has made major advances toward a new platform technology facilitating form factor-free devices. 3D printing techniques have attracted significant attention in the context of fabricating arbitrarily shaped circuits. Herein, a 3D-printable metallic ink comprising multidimensional eutectic gallium indium (EGaIn)/Ag hierarchical particles is proposed to fabricate arbitrarily designable solid/liquid biphasic conductors that can be inherently self-healed/chip bonded and do not suffer from liquid flood out due to their liquid and solid nature, respectively. The EGaIn/Ag hierarchical particles are designed to have plasmonic optical absorption at the visible green-red wavelength regime, which is elucidated by an optical simulation study, and also enable the direct transfer of thermal energy, generated in the vicinity of the Ag nanoparticles, to the surface of the EGaIn particles. The 3D surface conformal green laser irradiation process activates the evolution of the biphasic conductive layer from the as-printed insulating particulate one. The chemical/physical evolution is elucidated along with a photothermal simulation study for clarifying the suppression of undesirable side reactions. It is demonstrated that the biphasic conductors formed by successive 3D printing and the surface conformal green laser irradiation process exhibit electrical properties that have thus far been unexplored in solid metallic conductors.
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Affiliation(s)
- Jiyun Shim
- Department of Advanced Materials Engineering for Information and ElectronicsIntegrated Education Institute for Frontier Science & Technology (BK21 Four)Kyung Hee UniversityYongin-si17104Republic of Korea
| | - Yeon Uk Kim
- Department of Mechanical Design EngineeringKumoh National Institute of Technology61 Daehak-roGumiGyeongbuk39177Republic of Korea
| | - Young-Bin Kim
- Department of Applied PhysicsKyung Hee UniversityYongin-si17104Republic of Korea
| | - Seul Gi Ji
- Division of Advanced MaterialsKorea Research Institute of Chemical TechnologyDaejeon34114Republic of Korea
| | - Yeon Ju Kim
- Department of Advanced Materials Engineering for Information and ElectronicsIntegrated Education Institute for Frontier Science & Technology (BK21 Four)Kyung Hee UniversityYongin-si17104Republic of Korea
| | - Yejin Jo
- Department of Advanced Materials Engineering for Information and ElectronicsIntegrated Education Institute for Frontier Science & Technology (BK21 Four)Kyung Hee UniversityYongin-si17104Republic of Korea
| | - Eun Jung Lee
- Division of Advanced MaterialsKorea Research Institute of Chemical TechnologyDaejeon34114Republic of Korea
| | - Do-Gyeong Yuk
- Department of Aeronautics, Mechanical and Electronic Convergence EngineeringKumoh National Institute of Technology61 Daehak-roGumiGyeongbuk39177Republic of Korea
| | - Su Yeon Lee
- Division of Advanced MaterialsKorea Research Institute of Chemical TechnologyDaejeon34114Republic of Korea
| | - Sun Sook Lee
- Division of Advanced MaterialsKorea Research Institute of Chemical TechnologyDaejeon34114Republic of Korea
| | - Sun-Kyung Kim
- Department of Applied PhysicsKyung Hee UniversityYongin-si17104Republic of Korea
| | - Hyung-Seok Kim
- KHU-KIST Department of Converging Science and TechnologyKyung Hee UniversitySeoul02447Republic of Korea
| | - Jung Hwan Park
- Department of Aeronautics, Mechanical and Electronic Convergence EngineeringKumoh National Institute of Technology61 Daehak-roGumiGyeongbuk39177Republic of Korea
| | - Sunho Jeong
- Department of Advanced Materials Engineering for Information and ElectronicsIntegrated Education Institute for Frontier Science & Technology (BK21 Four)Kyung Hee UniversityYongin-si17104Republic of Korea
- KHU-KIST Department of Converging Science and TechnologyKyung Hee UniversitySeoul02447Republic of Korea
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28
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Chen S, Fan S, Qi J, Xiong Z, Qiao Z, Wu Z, Yeo JC, Lim CT. Ultrahigh Strain-Insensitive Integrated Hybrid Electronics Using Highly Stretchable Bilayer Liquid Metal Based Conductor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208569. [PMID: 36353902 DOI: 10.1002/adma.202208569] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Human-interfaced electronic systems require strain-resilient circuits. However, present integrated stretchable electronics easily suffer from electrical deterioration and face challenges in forming robust multilayered soft-rigid hybrid configurations. Here, a bilayer liquid-solid conductor (b-LSC) with amphiphilic properties is introduced to reliably interface with both rigid electronics and elastomeric substrates. The top liquid metal can self-solder its interface with rigid electronics at a resistance 30% lower than the traditional tin-soldered rigid interface. The bottom polar composite comprising liquid metal particles and polymers can not only reliably interface with elastomers but also help the b-LSC heal after breakage. The b-LSC can be scalably fabricated by printing and subsequent peeling strategies, showing ultra-high strain-insensitive conductivity (maximum 22 532 S cm-1 ), extreme stretchability (2260%), and negligible resistance change under ultra-high strain (0.34 times increase under 1000% strain). It can act as stretchable vertical interconnect access for connecting multilayered layouts and can be scalably and universally fabricated on various substrates with a resolution of ≈200 µm. It is demonstrated that it can construct stretchable sensor arrays, multi-layered stretchable displays, highly integrated haptic user-interactive optoelectric E-skins, visualized heaters, robot touch sensing systems, and wireless powering for wearable electronics.
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Affiliation(s)
- Shuwen Chen
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 119276, Singapore
| | - Shicheng Fan
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Jiaming Qi
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Ze Xiong
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 119276, Singapore
| | - Zheng Qiao
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Zixiong Wu
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Joo Chuan Yeo
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 119276, Singapore
| | - Chwee Teck Lim
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 119276, Singapore
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117544, Singapore
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29
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Zhao Z, Soni S, Lee T, Nijhuis CA, Xiang D. Smart Eutectic Gallium-Indium: From Properties to Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203391. [PMID: 36036771 DOI: 10.1002/adma.202203391] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/30/2022] [Indexed: 05/27/2023]
Abstract
Eutectic gallium-indium (EGaIn), a liquid metal with a melting point close to or below room temperature, has attracted extensive attention in recent years due to its excellent properties such as fluidity, high conductivity, thermal conductivity, stretchability, self-healing capability, biocompatibility, and recyclability. These features of EGaIn can be adjusted by changing the experimental condition, and various composite materials with extended properties can be further obtained by mixing EGaIn with other materials. In this review, not only the are unique properties of EGaIn introduced, but also the working principles for the EGaIn-based devices are illustrated and the developments of EGaIn-related techniques are summarized. The applications of EGaIn in various fields, such as flexible electronics (sensors, antennas, electronic circuits), molecular electronics (molecular memory, opto-electronic switches, or reconfigurable junctions), energy catalysis (heat management, motors, generators, batteries), biomedical science (drug delivery, tumor therapy, bioimaging and neural interfaces) are reviewed. Finally, a critical discussion of the main challenges for the development of EGaIn-based techniques are discussed, and the potential applications in new fields are prospected.
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Affiliation(s)
- Zhibin Zhao
- Institute of Modern Optics and Center of Single Molecule Sciences, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, 300350, Tianjin, P. R. China
| | - Saurabh Soni
- Department of Molecules and Materials, MESA+ Institute for Nanotechnology, Molecules Center and Center for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, Enschede, 7500 AE, The Netherlands
| | - Takhee Lee
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Christian A Nijhuis
- Department of Molecules and Materials, MESA+ Institute for Nanotechnology, Molecules Center and Center for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, Enschede, 7500 AE, The Netherlands
| | - Dong Xiang
- Institute of Modern Optics and Center of Single Molecule Sciences, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, 300350, Tianjin, P. R. China
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30
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Yang B, Yang Z, Tang L. Recent progress in fiber-based soft electronics enabled by liquid metal. Front Bioeng Biotechnol 2023; 11:1178995. [PMID: 37187888 PMCID: PMC10175636 DOI: 10.3389/fbioe.2023.1178995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/20/2023] [Indexed: 05/17/2023] Open
Abstract
Soft electronics can seamlessly integrate with the human skin which will greatly improve the quality of life in the fields of healthcare monitoring, disease treatment, virtual reality, and human-machine interfaces. Currently, the stretchability of most soft electronics is achieved by incorporating stretchable conductors with elastic substrates. Among stretchable conductors, liquid metals stand out for their metal-grade conductivity, liquid-grade deformability, and relatively low cost. However, the elastic substrates usually composed of silicone rubber, polyurethane, and hydrogels have poor air permeability, and long-term exposure can cause skin redness and irritation. The substrates composed of fibers usually have excellent air permeability due to their high porosity, making them ideal substrates for soft electronics in long-term applications. Fibers can be woven directly into various shapes, or formed into various shapes on the mold by spinning techniques such as electrospinning. Here, we provide an overview of fiber-based soft electronics enabled by liquid metals. An introduction to the spinning technology is provided. Typical applications and patterning strategies of liquid metal are presented. We review the latest progress in the design and fabrication of representative liquid metal fibers and their application in soft electronics such as conductors, sensors, and energy harvesting. Finally, we discuss the challenges of fiber-based soft electronics and provide an outlook on future prospects.
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Affiliation(s)
- Bowen Yang
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Zihan Yang
- Fashion Accessory Art and Engineering College, Beijing Institute of Fashion Technology, Beijing, China
- *Correspondence: Zihan Yang, ; Lixue Tang,
| | - Lixue Tang
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, School of Biomedical Engineering, Capital Medical University, Beijing, China
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Capital Medical University, Beijing, China
- *Correspondence: Zihan Yang, ; Lixue Tang,
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31
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High stretchability and conductive stability of flexible hybrid electronic materials for smart clothing. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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32
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Pozarycki TA, Hwang D, Barron EJ, Wilcox BT, Tutika R, Bartlett MD. Tough Bonding of Liquid Metal-Elastomer Composites for Multifunctional Adhesives. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2203700. [PMID: 36098240 DOI: 10.1002/smll.202203700] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/08/2022] [Indexed: 06/15/2023]
Abstract
Liquid metal (LM) composites, which consist of LM droplets dispersed in highly deformable elastomers, have recently gained interest as a multifunctional material for soft robotics and electronics. The incorporation of LM into elastic solids allows for unique combinations of material properties such as high stretchability with thermal and electrical conductivity comparable to metals. However, it is currently a challenge to incorporate LM composites into integrated systems consisting of diverse materials and components due to a lack of adhesion control. Here, a chemical anchoring methodology to increase adhesion of LM composites to diverse substrates is presented. The fracture energy increases up to 100× relative to untreated surfaces, with values reaching up to 7800 J m-2 . Furthermore, the fracture energy, tensile modulus, and thermal conductivity can be tuned together by controlling the microstructure of LM composites. Finally, the bonding technique is used to integrate LM composites with functional electronic components without encapsulation or clamping, allowing for extreme deformations while maintaining exceptional thermal and electrical conductivity. These findings can accelerate the adoption of LM composites into complex soft robotic and electronic systems where strong, reliable bonding between diverse materials and components is required.
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Affiliation(s)
- Tyler A Pozarycki
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Dohgyu Hwang
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Edward J Barron
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Brittan T Wilcox
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Ravi Tutika
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michael D Bartlett
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA, 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA, 24061, USA
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Cho C, Shin W, Kim M, Bang J, Won P, Hong S, Ko SH. Monolithically Programmed Stretchable Conductor by Laser-Induced Entanglement of Liquid Metal and Metallic Nanowire Backbone. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2202841. [PMID: 35901286 DOI: 10.1002/smll.202202841] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 06/19/2022] [Indexed: 06/15/2023]
Abstract
Owing to its low mechanical compliance, liquid metal is intrinsically suitable for stretchable electronics and future wearable devices. However, its invariable strain-resistance behavior according to the strain-induced geometrical deformation and the difficulty of circuit patterning limit the extensive use of liquid metal, especially for strain-insensitive wiring purposes. To overcome these limitations, herein, novel liquid-metal-based electrodes of fragmented eutectic gallium-indium alloy (EGaIn) and Ag nanowire (NW) backbone of which their entanglement is controlled by the laser-induced photothermal reaction to enable immediate and direct patterning of the stretchable electrode with spatially programmed strain-resistance characteristics are developed. The coexistence of fragmented EGaIn and AgNW backbone, that is, a biphasic metallic composite (BMC), primarily supports the uniform and durable formation of target layers on stretchable substrates. The laser-induced photothermal reaction not only promotes the adhesion between the BMC layer and substrates but also alters the structure of laser-irradiated BMC. By controlling the degree of entanglement between fragmented EGaIn and AgNW, the initial conductivity and local gauge factor are regulated and the electrode becomes effectively insensitive to applied strain. As the configuration developed in this study is compatible with both regimes of electrodes, it can open new routes for the rapid creation of complex stretchable circuitry through a single process.
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Affiliation(s)
- Chulmin Cho
- Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
- Mechatronics Research, Samsung Electronics, 1 Samsungjeonja-ro, Hwaseong-si, Gyeonggi-do, 18848, South Korea
| | - Wooseop Shin
- Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Minwoo Kim
- Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Junhyuk Bang
- Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Phillip Won
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Sukjoon Hong
- Department of Mechanical Engineering, BK21 FOUR ERICA-ACE Center, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, South Korea
| | - Seung Hwan Ko
- Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
- Institute of Advanced Machines and Design/Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
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34
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Guo R, Li T, Wu Z, Wan C, Niu J, Huo W, Yu H, Huang X. Thermal Transfer-Enabled Rapid Printing of Liquid Metal Circuits on Multiple Substrates. ACS APPLIED MATERIALS & INTERFACES 2022; 14:37028-37038. [PMID: 35938409 DOI: 10.1021/acsami.2c08743] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Low-cost, rapid patterning of liquid metal on various substrates is a key processing step for liquid metal-based soft electronics. Current patterning methods rely on expensive equipment and specific substrates, which severely limit their widespread applications. Based on surface adhesion adjustment of liquid metal through thermal transferring toner patterns, we present a universal printing technique of liquid metal circuits. Without using any expensive processing steps or equipment, the circuit patterns can be printed quickly on thermal transfer paper using a desktop laser printer, and a toner on the thermal transfer paper can be transferred to various smooth substrates and polymer-coated rough substrates. The technique has yielded liquid metal circuits with a minimum linewidth of 50 μm fabricated on various smooth, rough, and three-dimensional substrates with complex morphology. The liquid metal circuits can maintain their functions even under an extreme strain of 800%. Various circuits such as LED arrays, multiple sensors, a flexible display, a heating circuit, a radiofrequency identification circuit, and a 12-lead electrocardiogram circuit on various substrates have been demonstrated, indicating the great potential of such a technique to rapidly achieve large-area flexible circuits for wearable health monitoring, internet of things, and consumer electronics at low cost and high efficiency.
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Affiliation(s)
- Rui Guo
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Tianyu Li
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Ziyue Wu
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Chunxue Wan
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Jing Niu
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Wenxing Huo
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Haixia Yu
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
| | - Xian Huang
- Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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Tavakoli M, Alhais Lopes P, Hajalilou A, Silva AF, Reis Carneiro M, Carvalheiro J, Marques Pereira J, de Almeida AT. 3R Electronics: Scalable Fabrication of Resilient, Repairable, and Recyclable Soft-Matter Electronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203266. [PMID: 35697348 DOI: 10.1002/adma.202203266] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/19/2022] [Indexed: 06/15/2023]
Abstract
E-waste is rapidly turning into another man-made disaster. It is proposed that a paradigm shift toward a more sustainable future can be made through soft-matter electronics that are resilient, repairable if damaged, and recyclable (3R), provided that they achieve the same level of maturity as industrial electronics. This includes high-resolution patterning, multilayer implementation, microchip integration, and automated fabrication. Herein, a novel architecture of materials and methods for microchip-integrated condensed soft-matter 3R electronics is demonstrated. The 3R function is enabled by a biphasic liquid metal-based composite, a block copolymer with nonpermanent physical crosslinks, and an electrochemical technique for material recycling. In addition, an autonomous laser-patterning method for scalable circuit patterning with an exceptional resolution of <30 µm in seconds is developed. The phase-shifting property of the BCPs is utilized for vapor-assisted "soldering" circuit repairing and recycling. The process is performed entirely at room temperature, thereby opening the door for a wide range of heat-sensitive and biodegradable polymers for the next generation of green electronics. The implementation and recycling of sophisticated skin-mounted patches with embedded sensors, electrodes, antennas, and microchips that build a digital fingerprint of the human electrophysiological signals is demonstrated by collecting mechanical, electrical, optical, and thermal data from the epidermis.
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Affiliation(s)
- Mahmoud Tavakoli
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - Pedro Alhais Lopes
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - Abdollah Hajalilou
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - André F Silva
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - Manuel Reis Carneiro
- Soft Machines Lab, Mechanical Engineering, Carnegie Melon University, Pittsburgh, PA, 15213, USA
| | - José Carvalheiro
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - João Marques Pereira
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
| | - Aníbal T de Almeida
- Soft and Printed Microelectronics Lab, Institute of Systems and Robotics, University of Coimbra, Coimbra, 3030-290, Portugal
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36
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Maji P, Naskar K. Styrenic block copolymer‐based thermoplastic elastomers in smart applications: Advances in synthesis, microstructure, and structure–property relationships—A review. J Appl Polym Sci 2022. [DOI: 10.1002/app.52942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Purbasha Maji
- Rubber Technology Centre Indian Institute of Technology Kharagpur West Bengal India
| | - Kinsuk Naskar
- Rubber Technology Centre Indian Institute of Technology Kharagpur West Bengal India
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37
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Sanchez-Botero L, Shah DS, Kramer-Bottiglio R. Are Liquid Metals Bulk Conductors? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2109427. [PMID: 35293649 DOI: 10.1002/adma.202109427] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Stretchable electronics have potential in wide-reaching applications including wearables, personal health monitoring, and soft robotics. Many recent advances in stretchable electronics leverage liquid metals, particularly eutectic gallium-indium (EGaIn). A variety of EGaIn electromechanical behaviors have been reported, ranging from bulk conductor responses to effectively strain-insensitive responses. However, numerous measurement techniques have been used throughout the literature, making it difficult to directly compare the various proposed formulations. Here, the electromechanical responses of EGaIn found in the literature is reviewed and pure EGaIn is investigated using three electrical resistance measurement techniques: four point probe, two point probe, and Wheatstone bridge. The results indicate substantial differences in measured electromechanical behavior between the three methods, which can largely be accounted for by correcting for a fixed offset corresponding to the resistances of various parts of the measurement circuits. Yet, even accounting for several of these sources of experimental error, the average relative change in resistance of EGaIn is found to be lower than that predicted by the commonly used bulk conductor assumption, referred to as Pouillet's law. Building upon recent theories proposed in the literature, possible explanations for the discrepancies are discussed. Finally, suggestions are provided on experimental design to enable reproducible and interpretable research.
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Affiliation(s)
- Lina Sanchez-Botero
- School of Engineering & Applied Science, Yale University, New Haven, CT, 06511, USA
| | - Dylan S Shah
- School of Engineering & Applied Science, Yale University, New Haven, CT, 06511, USA
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38
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Jung D, Lim C, Park C, Kim Y, Kim M, Lee S, Lee H, Kim JH, Hyeon T, Kim DH. Adaptive Self-Organization of Nanomaterials Enables Strain-Insensitive Resistance of Stretchable Metallic Nanocomposites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200980. [PMID: 35388541 DOI: 10.1002/adma.202200980] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/30/2022] [Indexed: 06/14/2023]
Abstract
Highly conductive and stretchable nanocomposites are promising material candidates for skin electronics. However, the resistance of stretchable metallic nanocomposites highly depends on external strains, often deteriorating the performance of fabricated electronic devices. Here, a material strategy for the highly conductive and stretchable nanocomposites comprising metal nanomaterials of various dimensions and a viscoelastic block-copolymer matrix is presented. The resistance of the nanocomposites can be well retained under skin deformations (<50% strain). It is demonstrated that silver nanomaterials can self-organize inside the viscoelastic media in response to external strain when their surface is conjugated with 1-decanethiol. Distinct self-organization behaviors associated with nanomaterial dimensions and strain conditions are found. Adopting the optimum composition of 0D/1D/2D silver nanomaterials can render the resistance of the nanocomposites insensitive to uniaxial or biaxial strains. As a result, the resistance can be maintained with a variance of < 1% during 1000 stretching cycles under uniaxial and biaxial strains of <50% while a high conductivity of ≈31 000 S cm-1 is achieved.
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Affiliation(s)
- Dongjun Jung
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Chaehong Lim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Chansul Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yeongjun Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Minseong Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seunghwan Lee
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyunjin Lee
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jeong Hyun Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- School of Chemical and Biological Engineering, and 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
- School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea
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39
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Guymon GG, Malakooti MH. Multifunctional liquid metal polymer composites. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20210867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Gregory G. Guymon
- Department of Mechanical Engineering University of Washington Seattle Washington USA
- Institute for Nano‐Engineered Systems University of Washington Seattle Washington USA
| | - Mohammad H. Malakooti
- Department of Mechanical Engineering University of Washington Seattle Washington USA
- Institute for Nano‐Engineered Systems University of Washington Seattle Washington USA
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40
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Zhu P, He Z, Liu S, Liu L, Huang Y, Li J. A highly elastic conductive film prepared by bidirectional AS-LBL method. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2021.110868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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41
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Sequential Oxidation Strategy for the Fabrication of Liquid Metal Electrothermal Thin Film with Desired Printing and Functional Property. MICROMACHINES 2021; 12:mi12121539. [PMID: 34945389 PMCID: PMC8709429 DOI: 10.3390/mi12121539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/02/2021] [Accepted: 12/06/2021] [Indexed: 11/17/2022]
Abstract
Room temperature liquid metal (LM) showcases a great promise in the fields of flexible functional thin film due to its favorable characteristics of flexibility, inherent conductivity, and printability. Current fabrication strategies of liquid metal film are substrate structure specific and sustain from unanticipated smearing effects. Herein, this paper reported a facile fabrication of liquid metal composite film via sequentially regulating oxidation to change the adhesion characteristics, targeting the ability of electrical connection and electrothermal conversion. The composite film was then made of the electrically resistive layer (oxidizing liquid metal) and the insulating Polyimide film (PI film) substrate, which has the advantages of electrical insulation and ultra-wide temperature working range, and its thickness is only 50 μm. The electrical resistance of composite film can maintain constant for 6 h and could work normally. Additionally, the heating film exhibited excellent thermal switching characteristics that can reach temperature equilibrium within 100 s, and recovery to ambient temperature within 50 s. The maximum working temperature of the as-prepared film is 115 °C, which is consistent with the result of the theoretical calculation, demonstrating a good electrothermal conversion capability. Finally, the heating application under extreme low temperature (−196 °C) was achieved. This conceptual study showed the promising value of the prototype strategy to the specific application areas such as the field of smart homes, flexible electronics, wearable thermal management, and high-performance heating systems.
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42
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Xie W, Allioux FM, Namivandi-Zangeneh R, Ghasemian MB, Han J, Rahim MA, Tang J, Yang J, Mousavi M, Mayyas M, Cao Z, Centurion F, Christoe MJ, Zhang C, Wang Y, Merhebi S, Baharfar M, Ng G, Esrafilzadeh D, Boyer C, Kalantar-Zadeh K. Polydopamine Shell as a Ga 3+ Reservoir for Triggering Gallium-Indium Phase Separation in Eutectic Gallium-Indium Nanoalloys. ACS NANO 2021; 15:16839-16850. [PMID: 34613693 DOI: 10.1021/acsnano.1c07278] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Low melting point eutectic systems, such as the eutectic gallium-indium (EGaIn) alloy, offer great potential in the domain of nanometallurgy; however, many of their interfacial behaviors remain to be explored. Here, a compositional change of EGaIn nanoalloys triggered by polydopamine (PDA) coating is demonstrated. Incorporating PDA on the surface of EGaIn nanoalloys renders core-shell nanostructures that accompany Ga-In phase separation within the nanoalloys. The PDA shell keeps depleting the Ga3+ from the EGaIn nanoalloys when the synthesis proceeds, leading to a Ga3+-coordinated PDA coating and a smaller nanoalloy. During this process, the eutectic nanoalloys turn into non-eutectic systems that ultimately result in the solidification of In when Ga is fully depleted. The reaction of Ga3+-coordinated PDA-coated nanoalloys with nitrogen dioxide gas is presented as an example for demonstrating the functionality of such hybrid composites. The concept of phase-separating systems, with polymeric reservoirs, may lead to tailored materials and can be explored on a variety of post-transition metals.
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Affiliation(s)
- Wanjie Xie
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Francois-Marie Allioux
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | | | - Mohammad B Ghasemian
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Jialuo Han
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Md Arifur Rahim
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Jianbo Tang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Jiong Yang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Maedehsadat Mousavi
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Mohannad Mayyas
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Zhenbang Cao
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Franco Centurion
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Michael J Christoe
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Chengchen Zhang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Yifang Wang
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Salma Merhebi
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Mahroo Baharfar
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Gervase Ng
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Cyrille Boyer
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
| | - Kourosh Kalantar-Zadeh
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia
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43
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Reversible polymer-gel transition for ultra-stretchable chip-integrated circuits through self-soldering and self-coating and self-healing. Nat Commun 2021; 12:4666. [PMID: 34344880 PMCID: PMC8333313 DOI: 10.1038/s41467-021-25008-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 07/16/2021] [Indexed: 11/23/2022] Open
Abstract
Integration of solid-state microchips into soft-matter, and stretchable printed electronics has been the biggest challenge against their scalable fabrication. We introduce, Pol-Gel, a simple technique for self-soldering, self-encapsulation, and self-healing, that allows low cost, scalable, and rapid fabrication of hybrid microchip-integrated ultra-stretchable circuits. After digitally printing the circuit, and placing the microchips, we trigger a Polymer-Gel transition in physically cross-linked block copolymers substrate, and silver liquid metal composite ink, by exposing the circuits to the solvent vapor. Once in the gel state, microchips penetrate to the ink and the substrate (Self-Soldering), and the ink penetrates to the substrate (Self-encapsulation). Maximum strain tolerance of ~1200% for printed stretchable traces, and >500% for chip-integrated soft circuits is achieved, which is 5x higher than the previous works. We demonstrate condensed soft-matter patches and e-textiles with integrated sensors, processors, and wireless communication, and repairing of a fully cut circuits through Pol-Gel. Despite advances on fabrication of stretchable interconnects, realizing functional electronics with integrated solid-state technology (SST) remains a challenge. Here, the authors report a reversible Pol-Gel transition method for fabrication of liquid-metal based, chip-integrated, printed stretchable circuits.
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44
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Abstract
Soft wearable electronics are rapidly developing through exploration of new materials, fabrication approaches, and design concepts. Although there have been many efforts for decades, a resurgence of interest in liquid metals (LMs) for sensing and wiring functional properties of materials in soft wearable electronics has brought great advances in wearable electronics and materials. Various forms of LMs enable many routes to fabricate flexible and stretchable sensors, circuits, and functional wearables with many desirable properties. This review article presents a systematic overview of recent progresses in LM-enabled wearable electronics that have been achieved through material innovations and the discovery of new fabrication approaches and design architectures. We also present applications of wearable LM technologies for physiological sensing, activity tracking, and energy harvesting. Finally, we discuss a perspective on future opportunities and challenges for wearable LM electronics as this field continues to grow.
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Affiliation(s)
- Phillip Won
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea
| | - Seongmin Jeong
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea
| | - Carmel Majidi
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Seung Hwan Ko
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea
- Institute of Advanced Machines and Design / Institute of Engineering Research, Seoul National University, Seoul 08826, Korea
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