1
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Coghi P, Coluccini C. Literature Review on Conjugated Polymers as Light-Sensitive Materials for Photovoltaic and Light-Emitting Devices in Photonic Biomaterial Applications. Polymers (Basel) 2024; 16:1407. [PMID: 38794599 PMCID: PMC11125275 DOI: 10.3390/polym16101407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/11/2024] [Indexed: 05/26/2024] Open
Abstract
Due to their extended p-orbital delocalization, conjugated polymers absorb light in the range of visible-NIR frequencies. We attempt to exploit this property to create materials that compete with inorganic semiconductors in photovoltaic and light-emitting materials. Beyond competing for applications in photonic devices, organic conjugated compounds, polymers, and small molecules have also been extended to biomedical applications like phototherapy and biodetection. Recent research on conjugated polymers has focused on bioapplications based on the absorbed light energy conversions in electric impulses, chemical energy, heat, and light emission. In this review, we describe the working principles of those photonic devices that have been applied and researched in the field of biomaterials.
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Affiliation(s)
- Paolo Coghi
- Laboratory for Drug Discovery from Natural Resources & Industrialization, School of Pharmacy, Macau University of Science and Technology, Macau 999078, China;
| | - Carmine Coluccini
- Institute of New Drug Development, College of Medicine, China Medical University, No. 91 Hsueh-Shih Road, Taichung 40402, Taiwan
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2
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Sporer M, Vasilas IG, Adzemovic A, Graber N, Reich S, Gueli C, Eickenscheidt M, Diester I, Stieglitz T, Ortmanns M. NeuroBus - Architecture for an Ultra-Flexible Neural Interface. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2024; 18:247-262. [PMID: 38227403 DOI: 10.1109/tbcas.2024.3354785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
This article presents the system architecture for an implant concept called NeuroBus. Tiny distributed direct digitizing neural recorder ASICs on an ultra-flexible polyimide substrate are connected in a bus-like structure, allowing short connections between electrode and recording front-end with low wiring effort and high customizability. The small size (344 μm × 294 μm) of the ASICs and the ultraflexible substrate allow a low bending stiffness, enabling the implant to adapt to the curvature of the brain and achieving high structural biocompatibility. We introduce the architecture, the integrated building blocks, and the post-CMOS processes required to realize a NeuroBus, and we characterize the prototyped direct digitizing neural recorder front-end as well as polyimide-based ECoG brain interface. A rodent animal model is further used to validate the joint capability of the recording front-end and thin-film electrode array.
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3
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Bhatia A, Hanna J, Stuart T, Kasper KA, Clausen DM, Gutruf P. Wireless Battery-free and Fully Implantable Organ Interfaces. Chem Rev 2024; 124:2205-2280. [PMID: 38382030 DOI: 10.1021/acs.chemrev.3c00425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Advances in soft materials, miniaturized electronics, sensors, stimulators, radios, and battery-free power supplies are resulting in a new generation of fully implantable organ interfaces that leverage volumetric reduction and soft mechanics by eliminating electrochemical power storage. This device class offers the ability to provide high-fidelity readouts of physiological processes, enables stimulation, and allows control over organs to realize new therapeutic and diagnostic paradigms. Driven by seamless integration with connected infrastructure, these devices enable personalized digital medicine. Key to advances are carefully designed material, electrophysical, electrochemical, and electromagnetic systems that form implantables with mechanical properties closely matched to the target organ to deliver functionality that supports high-fidelity sensors and stimulators. The elimination of electrochemical power supplies enables control over device operation, anywhere from acute, to lifetimes matching the target subject with physical dimensions that supports imperceptible operation. This review provides a comprehensive overview of the basic building blocks of battery-free organ interfaces and related topics such as implantation, delivery, sterilization, and user acceptance. State of the art examples categorized by organ system and an outlook of interconnection and advanced strategies for computation leveraging the consistent power influx to elevate functionality of this device class over current battery-powered strategies is highlighted.
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Affiliation(s)
- Aman Bhatia
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Jessica Hanna
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Tucker Stuart
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Kevin Albert Kasper
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - David Marshall Clausen
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Philipp Gutruf
- Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Department of Electrical and Computer Engineering, The University of Arizona, Tucson, Arizona 85721, United States
- Bio5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
- Neuroscience Graduate Interdisciplinary Program (GIDP), The University of Arizona, Tucson, Arizona 85721, United States
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4
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Che Z, O'Donovan S, Xiao X, Wan X, Chen G, Zhao X, Zhou Y, Yin J, Chen J. Implantable Triboelectric Nanogenerators for Self-Powered Cardiovascular Healthcare. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207600. [PMID: 36759957 DOI: 10.1002/smll.202207600] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Triboelectric nanogenerators (TENGs) have gained significant traction in recent years in the bioengineering community. With the potential for expansive applications for biomedical use, many individuals and research groups have furthered their studies on the topic, in order to gain an understanding of how TENGs can contribute to healthcare. More specifically, there have been a number of recent studies focusing on implantable triboelectric nanogenerators (I-TENGs) toward self-powered cardiac systems healthcare. In this review, the progression of implantable TENGs for self-powered cardiovascular healthcare, including self-powered cardiac monitoring devices, self-powered therapeutic devices, and power sources for cardiac pacemakers, will be systematically reviewed. Long-term expectations of these implantable TENG devices through their biocompatibility and other utilization strategies will also be discussed.
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Affiliation(s)
- Ziyuan Che
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Sarah O'Donovan
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xiao Xiao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xiao Wan
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Guorui Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xun Zhao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yihao Zhou
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Junyi Yin
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jun Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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5
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Shankar S, Murphy BB, Driscoll N, Shekhirev M, Valurouthu G, Shevchuk K, Anayee M, Cimino F, Gogotsi Y, Vitale F. Effect of the deposition process on the stability of Ti 3C 2T x MXene films for bioelectronics. 2D MATERIALS 2023; 10:044001. [PMID: 37521001 PMCID: PMC10373437 DOI: 10.1088/2053-1583/ace26c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Ti3C2Tx MXene is emerging as the enabling material in a broad range of wearable and implantable medical technologies, thanks to its outstanding electrical, electrochemical, and optoelectronic properties, and its compatibility with high-throughput solution-based processing. While the prevalence of Ti3C2Tx MXene in biomedical research, and in particular bioelectronics, has steadily increased, the long-term stability and degradation of Ti3C2Tx MXene films have not yet been thoroughly investigated, limiting its use for chronic applications. Here, we investigate the stability of Ti3C2Tx films and electrodes under environmental conditions that are relevant to medical and bioelectronic technologies: storage in ambient atmosphere (shelf-life), submersion in saline (akin to the in vivo environment), and storage in a desiccator (low-humidity). Furthermore, to evaluate the effect of the MXene deposition method and thickness on the film stability in the different conditions, we compare thin (25 nm), and thick (1.0 μm) films and electrodes fabricated via spray-coating and blade-coating. Our findings indicate that film processing method and thickness play a significant role in determining the long-term performance of Ti3C2Tx films and electrodes, with highly aligned, thick films from blade coating remarkably retaining their conductivity, electrochemical impedance, and morphological integrity even after 30 days in saline. Our extensive spectroscopic analysis reveals that the degradation of Ti3C2Tx films in high-humidity environments is primarily driven by moisture intercalation, ingress, and film delamination, with evidence of only minimal to moderate oxidation.
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Affiliation(s)
- Sneha Shankar
- Department of Bioengineering, 210 S. 33rd Street, 240 Skirkanich Hall
- Center for Neuroengineering & Therapeutics, 240 S. 33rd Street, 301 Hayden Hall
- Center for Neurotrauma, Neurodegeneration, and Restoration, 3900 Woodlawn Ave., Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States 19104
| | - Brendan B. Murphy
- Center for Neuroengineering & Therapeutics, 240 S. 33rd Street, 301 Hayden Hall
- Department of Neurology, 3400 Spruce Street, University of Pennsylvania, Philadelphia, PA, United States 19104
- Center for Neurotrauma, Neurodegeneration, and Restoration, 3900 Woodlawn Ave., Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States 19104
| | - Nicolette Driscoll
- Department of Bioengineering, 210 S. 33rd Street, 240 Skirkanich Hall
- Center for Neuroengineering & Therapeutics, 240 S. 33rd Street, 301 Hayden Hall
- Center for Neurotrauma, Neurodegeneration, and Restoration, 3900 Woodlawn Ave., Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States 19104
| | - Mikhail Shekhirev
- A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, 3141 Chestnut Street, Drexel University, Philadelphia, PA, United States 19104
| | - Geetha Valurouthu
- A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, 3141 Chestnut Street, Drexel University, Philadelphia, PA, United States 19104
| | - Kateryna Shevchuk
- A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, 3141 Chestnut Street, Drexel University, Philadelphia, PA, United States 19104
| | - Mark Anayee
- A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, 3141 Chestnut Street, Drexel University, Philadelphia, PA, United States 19104
| | - Francesca Cimino
- Department of Bioengineering, 210 S. 33rd Street, 240 Skirkanich Hall
- Center for Neuroengineering & Therapeutics, 240 S. 33rd Street, 301 Hayden Hall
| | - Yury Gogotsi
- A. J. Drexel Nanomaterials Institute, Department of Materials Science and Engineering, 3141 Chestnut Street, Drexel University, Philadelphia, PA, United States 19104
| | - Flavia Vitale
- Center for Neuroengineering & Therapeutics, 240 S. 33rd Street, 301 Hayden Hall
- Department of Neurology, 3400 Spruce Street, University of Pennsylvania, Philadelphia, PA, United States 19104
- Department of Physical Medicine & Rehabilitation, 1800 Lombard Street, University of Pennsylvania, Philadelphia, PA, United States 19147
- Center for Neurotrauma, Neurodegeneration, and Restoration, 3900 Woodlawn Ave., Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States 19104
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Kam KA, Lardner CK, Dumitriu D, Kymissis I. Methodology for Safe and Effective Subcutaneous Implantation of Wireless Biotelemetry Sensor Devices in Rodents. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083319 DOI: 10.1109/embc40787.2023.10340211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
In this work, a methodology for assessing the impact of implantation surgery on laboratory mice on behavior was created. The study included the design of several implants fabricated on various printed circuit board (PCB) technologies with overall diameters between 26-28mm and weights between 4.5-6.5g. 11 adult CD1 mice were implanted with the devices and their behavior was analyzed using common behavioral benchmark tests. The results show that implants designed to be 10% of the animal's body weight showed no adverse effects on mobility or social behavior. These results illustrate a method to identify and reduce the adverse behavioral changes inherent to device implantation. Additional considerations for implant surgery are provided. These results are validated with the implantation of a Bluetooth Low Energy (BLE) wireless sensor tag. The implanted wireless tag showed an average Received Signal Strength Indicator (RSSI) of 62.96dBm with a standard deviation of 4.95dBm and a variance of 24.5 dBm2. The high RSSI and variance values show that the implant was working well inside of the mouse's body and that the mouse was fully recovered and readily exploring its surroundings.Clinical Relevance-This work 1) studies the behavioral impact of implantable wireless biopotential devices. This will help clinical researchers conducting behavioral studies using sensor implants. 2) demonstrates a working implanted BLE wireless model inside of a mouse. Various wireless connectivity metrics are studied.
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7
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Ruhunage C, Dhawan V, Nawarathne CP, Hoque A, Cui XT, Alvarez NT. Evaluation of Polymer-Coated Carbon Nanotube Flexible Microelectrodes for Biomedical Applications. Bioengineering (Basel) 2023; 10:647. [PMID: 37370578 DOI: 10.3390/bioengineering10060647] [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: 04/18/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
The demand for electrically insulated microwires and microfibers in biomedical applications is rapidly increasing. Polymer protective coatings with high electrical resistivity, good chemical resistance, and a long shelf-life are critical to ensure continuous device operation during chronic applications. As soft and flexible electrodes can minimize mechanical mismatch between tissues and electronics, designs based on flexible conductive microfibers, such as carbon nanotube (CNT) fibers, and soft polymer insulation have been proposed. In this study, a continuous dip-coating approach was adopted to insulate meters-long CNT fibers with hydrogenated nitrile butadiene rubber (HNBR), a soft and rubbery insulating polymer. Using this method, 4.8 m long CNT fibers with diameters of 25-66 µm were continuously coated with HNBR without defects or interruptions. The coated CNT fibers were found to be uniform, pinhole free, and biocompatible. Furthermore, the HNBR coating had better high-temperature tolerance than conventional insulating materials. Microelectrodes prepared using the HNBR-coated CNT fibers exhibited stable electrochemical properties, with a specific impedance of 27.0 ± 9.4 MΩ µm2 at 1.0 kHz and a cathodal charge storage capacity of 487.6 ± 49.8 mC cm-2. Thus, the developed electrodes express characteristics that made them suitable for use in implantable medical devices for chronic in vivo applications.
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Affiliation(s)
- Chethani Ruhunage
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Vaishnavi Dhawan
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | | | - Abdul Hoque
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Noe T Alvarez
- Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, USA
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8
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Novák M, Rosina J, Bendová H, Kejlová K, Vlková A, Rucki M, Svobodová L, Gürlich R, Hajer J. Low-cost and prototype-friendly method for biocompatible encapsulation of implantable electronics with epoxy overmolding, hermetic feedthroughs and P3HT coating. Sci Rep 2023; 13:1644. [PMID: 36717683 PMCID: PMC9887057 DOI: 10.1038/s41598-023-28699-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
The research of novel implantable medical devices is one of the most attractive, yet complex areas in the biomedical field. The design and development of sufficiently small devices working in an in vivo environment is challenging but successful encapsulation of such devices is even more so. Industry-standard methods using glass and titanium are too expensive and tedious, and epoxy or silicone encapsulation is prone to water ingress with cable feedthroughs being the most frequent point of failure. This paper describes a universal and straightforward method for reliable encapsulation of circuit boards that achieves ISO10993 compliance. A two-part PVDF mold was machined using a conventional 3-axis machining center. Then, the circuit board with a hermetic feedthrough was placed in the mold and epoxy resin was injected into the mold under pressure to fill the cavity. Finally, the biocompatibility was further enhanced with an inert P3HT polymer coating which can be easily formulated into an ink. The biocompatibility of the encapsulants was assessed according to ISO10993. The endurance of the presented solution compared to silicone potting and epoxy potting was assessed by submersion in phosphate-buffered saline solution at 37 °C. The proposed method showed superior results to PDMS and simple epoxy potting.
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Affiliation(s)
- Marek Novák
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic. .,Department of Medical Biophysics and Medical Informatics, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
| | - Jozef Rosina
- Department of Medical Biophysics and Medical Informatics, Third Faculty of Medicine, Charles University, Prague, Czech Republic.,Department of Health Care and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Hana Bendová
- Centre of Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic
| | - Kristina Kejlová
- Centre of Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic
| | - Alena Vlková
- Centre of Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic
| | - Marian Rucki
- Centre of Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic
| | - Lada Svobodová
- Centre of Toxicology and Health Safety, National Institute of Public Health, Prague, Czech Republic
| | - Robert Gürlich
- Department of General Surgery, Third Faculty of Medicine, Charles University, University Hospital Královské Vinohrady, Prague, Czech Republic
| | - Jan Hajer
- Department of Internal Medicine, Third Faculty of Medicine, Charles University, University Hospital Královské Vinohrady, Prague, Czech Republic.
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Selbmann F, Scherf C, Langenickel J, Roscher F, Wiemer M, Kuhn H, Joseph Y. Impact of Non-Accelerated Aging on the Properties of Parylene C. Polymers (Basel) 2022; 14:polym14235246. [PMID: 36501649 PMCID: PMC9740118 DOI: 10.3390/polym14235246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/20/2022] [Accepted: 11/24/2022] [Indexed: 12/05/2022] Open
Abstract
The polymer Parylene combines a variety of excellent properties and, hence, is an object of intensive research for packaging applications, such as the direct encapsulation of medical implants. Moreover, in the past years, an increasing interest for establishing new applications for Parylene is observed. These include the usage of Parylene as a flexible substrate, a dielectric, or a material for MEMS, e.g., a bonding adhesive. The increasing importance of Parylene raises questions regarding the long-term reliability and aging of Parylene as well as the impact of the aging on the Parylene properties. Within this paper, we present the first investigations on non-accelerated Parylene C aging for a period of about five years. Doing so, free-standing Parylene membranes were fabricated to investigate the barrier properties, the chemical stability, as well as the optical properties of Parylene in dependence on different post-treatments to the polymer. These properties were found to be excellent and with only a minor age-related impact. Additionally, the mechanical properties, i.e., the Young's modulus and the hardness, were investigated via nano-indentation over the same period of time. For both mechanical properties only, minor changes were observed. The results prove that Parylene C is a highly reliable polymer for applications that needs a high long-term stability.
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Affiliation(s)
- Franz Selbmann
- Fraunhofer Institute for Electronic Nano Systems ENAS, Technologie-Campus 3, 09126 Chemnitz, Germany
- Institute for Electronic and Sensor Materials, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 3, 09599 Freiberg, Germany
| | - Christina Scherf
- Fraunhofer Institute for Electronic Nano Systems ENAS, Technologie-Campus 3, 09126 Chemnitz, Germany
| | - Jörn Langenickel
- Center for Microtechnologies, TU Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Frank Roscher
- Fraunhofer Institute for Electronic Nano Systems ENAS, Technologie-Campus 3, 09126 Chemnitz, Germany
| | - Maik Wiemer
- Fraunhofer Institute for Electronic Nano Systems ENAS, Technologie-Campus 3, 09126 Chemnitz, Germany
| | - Harald Kuhn
- Fraunhofer Institute for Electronic Nano Systems ENAS, Technologie-Campus 3, 09126 Chemnitz, Germany
- Center for Microtechnologies, TU Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, Germany
| | - Yvonne Joseph
- Institute for Electronic and Sensor Materials, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 3, 09599 Freiberg, Germany
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10
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Sang M, Kim K, Shin J, Yu KJ. Ultra-Thin Flexible Encapsulating Materials for Soft Bio-Integrated Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202980. [PMID: 36031395 PMCID: PMC9596833 DOI: 10.1002/advs.202202980] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/22/2022] [Indexed: 05/11/2023]
Abstract
Recently, bioelectronic devices extensively researched and developed through the convergence of flexible biocompatible materials and electronics design that enables more precise diagnostics and therapeutics in human health care and opens up the potential to expand into various fields, such as clinical medicine and biomedical research. To establish an accurate and stable bidirectional bio-interface, protection against the external environment and high mechanical deformation is essential for wearable bioelectronic devices. In the case of implantable bioelectronics, special encapsulation materials and optimized mechanical designs and configurations that provide electronic stability and functionality are required for accommodating various organ properties, lifespans, and functions in the biofluid environment. Here, this study introduces recent developments of ultra-thin encapsulations with novel materials that can preserve or even improve the electrical performance of wearable and implantable bio-integrated electronics by supporting safety and stability for protection from destruction and contamination as well as optimizing the use of bioelectronic systems in physiological environments. In addition, a summary of the materials, methods, and characteristics of the most widely used encapsulation technologies is introduced, thereby providing a strategic selection of appropriate choices of recently developed flexible bioelectronics.
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Affiliation(s)
- Mingyu Sang
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Kyubeen Kim
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Jongwoon Shin
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
| | - Ki Jun Yu
- School of Electrical and Electronic EngineeringYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
- YU‐KIST InstituteYonsei University50 Yonsei‐ro, SeodaemunguSeoul03722Republic of Korea
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11
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Zhuang X, Zhang S, Ma W. Properties of composite film based on sucrose polyaldehyde cross‐linked polyhydroxyethyl acrylate and starch. J Appl Polym Sci 2022. [DOI: 10.1002/app.53140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Xuechen Zhuang
- State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian People's Republic of China
| | - Shufen Zhang
- State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian People's Republic of China
| | - Wei Ma
- State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian People's Republic of China
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12
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Mariello M, Kim K, Wu K, Lacour SP, Leterrier Y. Recent Advances in Encapsulation of Flexible Bioelectronic Implants: Materials, Technologies, and Characterization Methods. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201129. [PMID: 35353928 DOI: 10.1002/adma.202201129] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/13/2022] [Indexed: 06/14/2023]
Abstract
Bioelectronic implantable systems (BIS) targeting biomedical and clinical research should combine long-term performance and biointegration in vivo. Here, recent advances in novel encapsulations to protect flexible versions of such systems from the surrounding biological environment are reviewed, focusing on material strategies and synthesis techniques. Considerable effort is put on thin-film encapsulation (TFE), and specifically organic-inorganic multilayer architectures as a flexible and conformal alternative to conventional rigid cans. TFE is in direct contact with the biological medium and thus must exhibit not only biocompatibility, inertness, and hermeticity but also mechanical robustness, conformability, and compatibility with the manufacturing of microfabricated devices. Quantitative characterization methods of the barrier and mechanical performance of the TFE are reviewed with a particular emphasis on water-vapor transmission rate through electrical, optical, or electrochemical principles. The integrability and functionalization of TFE into functional bioelectronic interfaces are also discussed. TFE represents a must-have component for the next-generation bioelectronic implants with diagnostic or therapeutic functions in human healthcare and precision medicine.
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Affiliation(s)
- Massimo Mariello
- Laboratory for Processing of Advanced Composites (LPAC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland
| | - Kyungjin Kim
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Electrical and MicroEngineering, Institute of Bioengineering, Centre for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Kangling Wu
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Electrical and MicroEngineering, Institute of Bioengineering, Centre for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Stéphanie P Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology, Laboratory for Soft Bioelectronic Interfaces, Institute of Electrical and MicroEngineering, Institute of Bioengineering, Centre for Neuroprosthetics, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Yves Leterrier
- Laboratory for Processing of Advanced Composites (LPAC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH-1015, Switzerland
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13
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Zhang R, Madhavi V, Shaffer TD, Androsch R, Schick C. Cyclic Olefin Copolymers (COC) – Excellent Glass Formers with Low Dynamic Fragility. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rui Zhang
- Institute of Physics and Competence Centre°CALOR University of Rostock Rostock 18051 Germany
- Interdisciplinary Center for Transfer‐oriented Research in Natural Sciences (IWE TFN) Martin Luther University Halle‐Wittenberg Halle/Saale 06099 Germany
| | | | | | - René Androsch
- Interdisciplinary Center for Transfer‐oriented Research in Natural Sciences (IWE TFN) Martin Luther University Halle‐Wittenberg Halle/Saale 06099 Germany
| | - Christoph Schick
- Institute of Physics and Competence Centre°CALOR University of Rostock Rostock 18051 Germany
- Butlerov Institute of Chemistry Kazan Federal University 18 Kremlyovskaya Street Kazan 420008 Russia
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14
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Balakrishnan G, Song J, Mou C, Bettinger CJ. Recent Progress in Materials Chemistry to Advance Flexible Bioelectronics in Medicine. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2106787. [PMID: 34751987 PMCID: PMC8917047 DOI: 10.1002/adma.202106787] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/15/2021] [Indexed: 05/09/2023]
Abstract
Designing bioelectronic devices that seamlessly integrate with the human body is a technological pursuit of great importance. Bioelectronic medical devices that reliably and chronically interface with the body can advance neuroscience, health monitoring, diagnostics, and therapeutics. Recent major efforts focus on investigating strategies to fabricate flexible, stretchable, and soft electronic devices, and advances in materials chemistry have emerged as fundamental to the creation of the next generation of bioelectronics. This review summarizes contemporary advances and forthcoming technical challenges related to three principal components of bioelectronic devices: i) substrates and structural materials, ii) barrier and encapsulation materials, and iii) conductive materials. Through notable illustrations from the literature, integration and device fabrication strategies and associated challenges for each material class are highlighted.
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Affiliation(s)
| | - Jiwoo Song
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
| | - Chenchen Mou
- Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA, 15213, USA
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15
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Flexible Liquid Crystal Polymer Technologies from Microwave to Terahertz Frequencies. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041336. [PMID: 35209131 PMCID: PMC8877632 DOI: 10.3390/molecules27041336] [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: 01/13/2022] [Revised: 02/04/2022] [Accepted: 02/06/2022] [Indexed: 12/03/2022]
Abstract
With the emergence of fifth-generation (5G) cellular networks, millimeter-wave (mmW) and terahertz (THz) frequencies have attracted ever-growing interest for advanced wireless applications. The traditional printed circuit board materials have become uncompetitive at such high frequencies due to their high dielectric loss and large water absorption rates. As a promising high-frequency alternative, liquid crystal polymers (LCPs) have been widely investigated for use in circuit devices, chip integration, and module packaging over the last decade due to their low loss tangent up to 1.8 THz and good hermeticity. The previous review articles have summarized the chemical properties of LCP films, flexible LCP antennas, and LCP-based antenna-in-package and system-in-package technologies for 5G applications, although these articles did not discuss synthetic LCP technologies. In addition to wireless applications, the attractive mechanical, chemical, and thermal properties of LCP films enable interesting applications in micro-electro-mechanical systems (MEMS), biomedical electronics, and microfluidics, which have not been summarized to date. Here, a comprehensive review of flexible LCP technologies covering electric circuits, antennas, integration and packaging technologies, front-end modules, MEMS, biomedical devices, and microfluidics from microwave to THz frequencies is presented for the first time, which gives a broad introduction for those outside or just entering the field and provides perspective and breadth for those who are well established in the field.
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16
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Fu X, Li G, Niu Y, Xu J, Wang P, Zhou Z, Ye Z, Liu X, Xu Z, Yang Z, Zhang Y, Lei T, Zhang B, Li Q, Cao A, Jiang T, Duan X. Carbon-Based Fiber Materials as Implantable Depth Neural Electrodes. Front Neurosci 2022; 15:771980. [PMID: 35002602 PMCID: PMC8730365 DOI: 10.3389/fnins.2021.771980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/29/2021] [Indexed: 01/02/2023] Open
Abstract
Implantable brain electrophysiology electrodes are valuable tools in both fundamental and applied neuroscience due to their ability to record neural activity with high spatiotemporal resolution from shallow and deep brain regions. Their use has been hindered, however, by the challenges in achieving chronically stable operations. Furthermore, implantable depth neural electrodes can only carry out limited data sampling within predefined anatomical regions, making it challenging to perform large-area brain mapping. Minimizing inflammatory responses and associated gliosis formation, and improving the durability and stability of the electrode insulation layers are critical to achieve long-term stable neural recording and stimulation. Combining electrophysiological measurements with simultaneous whole-brain imaging techniques, such as magnetic resonance imaging (MRI), provides a useful solution to alleviate the challenge in scalability of implantable depth electrodes. In recent years, various carbon-based materials have been used to fabricate flexible neural depth electrodes with reduced inflammatory responses and MRI-compatible electrodes, which allows structural and functional MRI mapping of the whole brain without obstructing any brain regions around the electrodes. Here, we conducted a systematic comparative evaluation on the electrochemical properties, mechanical properties, and MRI compatibility of different kinds of carbon-based fiber materials, including carbon nanotube fibers, graphene fibers, and carbon fibers. We also developed a strategy to improve the stability of the electrode insulation without sacrificing the flexibility of the implantable depth electrodes by sandwiching an inorganic barrier layer inside the polymer insulation film. These studies provide us with important insights into choosing the most suitable materials for next-generation implantable depth electrodes with unique capabilities for applications in both fundamental and translational neuroscience research.
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Affiliation(s)
- Xuefeng Fu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Gen Li
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Yutao Niu
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, China.,Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou, China
| | - Jingcao Xu
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Puxin Wang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Zhaoxiao Zhou
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Ziming Ye
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Xiaojun Liu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Zheng Xu
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Ziqian Yang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yongyi Zhang
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, China.,Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou, China
| | - Ting Lei
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Baogui Zhang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences (CAS), Beijing, China
| | - Qingwen Li
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, China.,Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Advanced Materials Division, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou, China
| | - Anyuan Cao
- School of Materials Science and Engineering, Peking University, Beijing, China
| | - Tianzai Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences (CAS), Beijing, China
| | - Xiaojie Duan
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,National Biomedical Imaging Center, Peking University, Beijing, China
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17
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Lamont C, Grego T, Nanbakhsh K, Shah Idil A, Giagka V, Vanhoestenberghe A, Cogan S, Donaldson N. Silicone encapsulation of thin-film SiO x, SiO xN yand SiC for modern electronic medical implants: a comparative long-term ageing study. J Neural Eng 2021; 18:055003. [PMID: 33752188 PMCID: PMC8208634 DOI: 10.1088/1741-2552/abf0d6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/22/2021] [Indexed: 02/03/2023]
Abstract
Objective.Ensuring the longevity of implantable devices is critical for their clinical usefulness. This is commonly achieved by hermetically sealing the sensitive electronics in a water impermeable housing, however, this method limits miniaturisation. Alternatively, silicone encapsulation has demonstrated long-term protection of implanted thick-film electronic devices. However, much of the current conformal packaging research is focused on more rigid coatings, such as parylene, liquid crystal polymers and novel inorganic layers. Here, we consider the potential of silicone to protect implants using thin-film technology with features 33 times smaller than thick-film counterparts.Approach.Aluminium interdigitated comb structures under plasma-enhanced chemical vapour deposited passivation (SiOx, SiOxNy, SiOxNy+ SiC) were encapsulated in medical grade silicones, with a total of six passivation/silicone combinations. Samples were aged in phosphate-buffered saline at 67 ∘C for up to 694 days under a continuous ±5 V biphasic waveform. Periodic electrochemical impedance spectroscopy measurements monitored for leakage currents and degradation of the metal traces. Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, focused-ion-beam and scanning-electron- microscopy were employed to determine any encapsulation material changes.Main results.No silicone delamination, passivation dissolution, or metal corrosion was observed during ageing. Impedances greater than 100 GΩ were maintained between the aluminium tracks for silicone encapsulation over SiOxNyand SiC passivations. For these samples the only observed failure mode was open-circuit wire bonds. In contrast, progressive hydration of the SiOxcaused its resistance to decrease by an order of magnitude.Significance.These results demonstrate silicone encapsulation offers excellent protection to thin-film conducting tracks when combined with appropriate inorganic thin films. This conclusion corresponds to previous reliability studies of silicone encapsulation in aqueous environments, but with a larger sample size. Therefore, we believe silicone encapsulation to be a realistic means of providing long-term protection for the circuits of implanted electronic medical devices.
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Affiliation(s)
- C Lamont
- Implanted Devices Group, Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, United Kingdom,Author to whom any correspondence should be addressed
| | - T Grego
- Implanted Devices Group, Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, United Kingdom
| | - K Nanbakhsh
- Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Delft, The Netherlands
| | - A Shah Idil
- Implanted Devices Group, Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, United Kingdom
| | - V Giagka
- Department of Microelectronics, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Delft, The Netherlands,
Department of System Integration and Interconnection Technologies, Fraunhofer Institute for Reliability and Micro-integration IZM, Berlin, Germany
| | - A Vanhoestenberghe
- Implanted Devices Group, Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, United Kingdom,
Institute of Orthopaedics and Musculoskeletal Science, RNOH Trust, University College London, Stanmore, United Kingdom
| | - S Cogan
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, United States of America
| | - N Donaldson
- Implanted Devices Group, Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, United Kingdom
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18
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Li J, Wang X. Materials Perspectives for Self-Powered Cardiac Implantable Electronic Devices toward Clinical Translation. ACCOUNTS OF MATERIALS RESEARCH 2021; 2:739-750. [PMID: 35386361 PMCID: PMC8979373 DOI: 10.1021/accountsmr.1c00078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Represented by pacemakers, implantable electronic devices (CIEDs) are playing a vital life-saving role in modern society. Although the current CIEDs are evolving quickly in terms of performance, safety, and miniaturization, the bulky and rigid battery creates the largest hurdle toward further development of a soft system that can be attached and conform to tissues without causing undesirable physiologic changes. Over 50% of patients with pacemakers require additional surgery procedures to replace a drained battery. Abrupt battery malfunction and failure contributes up to 2.4% of implanted leadless pacemakers. The battery also has risks of lethal interference with diagnostic magnetic resonance imaging (MRI). Applying the implantable nanogenerators (i-NGs) technology to CIEDs is regarded as a promising solution to the battery challenge and enables self-powering capability. I-NGs based on the principle of either triboelectricity (TENG) or piezoelectricity (PENG) can convert biomechanical energy into electricity effectively. Meanwhile, a complete heartbeat cycle provides a biomechanical energy of ~0.7 J or an average power of 0.93 W, which is sufficient for the operation of CIEDs considering the power consumption of 5-10 μW for a pacemaker and 10-100 μW for a cardiac defibrillator. It is therefore practical to leverage the effective, soft, flexible, lightweight, and biocompatible i-NGs to eliminate the bulky battery component in CIEDs and achieve self-sustainable operation. In this rapidly evolving interdisciplinary field, materials innovation acts as a cornerstone that frames the technology development. Here we bring a few critical perspectives regarding materials design and engineering, which are essential in leading the NG-powered CIEDs toward clinical translations. This Account starts with a brief introduction of the cardiac electrophysiology, as well as its short history to interface the state-of-the-art cardiac NG technologies. Three key components of NG-powered CIEDs are discussed in detail, including the NG device itself, the packaging material, and the stimulation electrodes. Cardiac NG is the essential component that converts heartbeat energy into electricity. It demands high-performance electromechanical coupling materials with long-term dynamic stability. The packaging material is critical to ensure a long-term stable operation of the device on a beating heart. Given the unique operation environment, a few criteria need to be considered in its development, including flexibility, biocompatibility, antifouling, hemocompatibility, and bioadhesion. The stimulation electrodes are the only material interfacing the heart tissue electrically. They should provide capacitive charge injection and mimic the soft and wet intrinsic tissues for the sake of stable biointerfaces. Driven by the rapid materials and device advancement, we envision that the evolution of NG-based CIEDs will quickly move from epicardiac to intracardiac, from single-function to multifunction, and with a minimal-invasive implantation procedure. This trend of development will open many research opportunities in emerging materials science and engineering, which will eventually lead the NG technology to a prevailing strategy for powering future CIEDs.
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Affiliation(s)
- Jun Li
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Xudong Wang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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19
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Turner BL, Senevirathne S, Kilgour K, McArt D, Biggs M, Menegatti S, Daniele MA. Ultrasound-Powered Implants: A Critical Review of Piezoelectric Material Selection and Applications. Adv Healthc Mater 2021; 10:e2100986. [PMID: 34235886 DOI: 10.1002/adhm.202100986] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/15/2021] [Indexed: 12/14/2022]
Abstract
Ultrasound-powered implants (UPIs) represent cutting edge power sources for implantable medical devices (IMDs), as their powering strategy allows for extended functional lifetime, decreased size, increased implant depth, and improved biocompatibility. IMDs are limited by their reliance on batteries. While batteries proved a stable power supply, batteries feature relatively large sizes, limited life spans, and toxic material compositions. Accordingly, energy harvesting and wireless power transfer (WPT) strategies are attracting increasing attention by researchers as alternative reliable power sources. Piezoelectric energy scavenging has shown promise for low power applications. However, energy scavenging devices need be located near sources of movement, and the power stream may suffer from occasional interruptions. WPT overcomes such challenges by more stable, on-demand power to IMDs. Among the various forms of WPT, ultrasound powering offers distinct advantages such as low tissue-mediated attenuation, a higher approved safe dose (720 mW cm-2 ), and improved efficiency at smaller device sizes. This study presents and discusses the state-of-the-art in UPIs by reviewing piezoelectric materials and harvesting devices including lead-based inorganic, lead-free inorganic, and organic polymers. A comparative discussion is also presented of the functional material properties, architecture, and performance metrics, together with an overview of the applications where UPIs are being deployed.
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Affiliation(s)
- Brendan L. Turner
- Joint Department of Biomedical Engineering North Carolina State University and University of North Carolina Chapel Hill, 911 Oval Dr. Raleigh NC 27695 USA
| | - Seedevi Senevirathne
- The Patrick G Johnston Centre for Cancer Research Queen's University 97 Lisburn Rd Belfast BT9 7AE UK
| | - Katie Kilgour
- Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh NC 27695 USA
| | - Darragh McArt
- The Patrick G Johnston Centre for Cancer Research Queen's University 97 Lisburn Rd Belfast BT9 7AE UK
| | - Manus Biggs
- Centre for Research in Medical Devices National University of Ireland Newcastle Road Galway H91 W2TY Ireland
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh NC 27695 USA
| | - Michael A. Daniele
- Joint Department of Biomedical Engineering North Carolina State University and University of North Carolina Chapel Hill, 911 Oval Dr. Raleigh NC 27695 USA
- Department of Electrical and Computer Engineering North Carolina State University 890 Oval Dr. Raleigh NC 27695 USA
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20
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Crovador R, Heim H, Cottam S, Feron K, Bhatia V, Louie F, Sherwood CP, Dastoor PC, Brichta AM, Lim R, Griffith MJ. Advanced Control of Drug Delivery for In Vivo Health Applications via Highly Biocompatible Self-Assembled Organic Nanoparticles. ACS APPLIED BIO MATERIALS 2021; 4:6338-6350. [PMID: 35006893 DOI: 10.1021/acsabm.1c00581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The use of nanostructured materials for targeted and controlled delivery of bioactive molecules is an attractive alternative to conventional drug administration protocols, enabling selective targeting of diseased cells, lower administered dosages, and reduced systemic side effects. Although a variety of nanocarriers have been investigated in recent years, electroactive organic polymer nanoparticles present several exciting advantages. Here we demonstrate that thin films created from nanoparticles synthesized from violanthrone-79, an n-type semiconducting organic material, can incorporate and release dexamethasone in vitro in a highly controlled manner. By systematically altering the nanoparticle formation chemistry, we successfully tailored the size of the nanoparticles between 30 and 145 nm to control the initial amount of drug loaded into the organic particles. The biocompatibility of the different particles was tested using live/dead assays of dorsal root ganglion neurons isolated and cultured from mice, revealing that elevated levels of the sodium dodecyl sulfate surfactant used to create the smaller nanoparticles are cytotoxic; however, cell survival rates in nanoparticles larger than 45 nm exceed 86% and promote neurite growth and elongation. By manipulating the electrical stimulus applied to the electroactive nanoparticle films, we show an accelerated rate of drug release in comparison to passive release in aqueous media. Furthermore, pulsing the electrical stimulus was successfully used to selectively switch the accelerated release rate on and off. By combining the tuning of drug loading (through tailored nanoparticle synthesis) and drug release rate (through electrical stimulus protocols), we demonstrate a highly advanced control of drug delivery dosage in a biocompatible delivery vehicle. This work highlights the significant potential of electroactive organic nanoparticles for implantable devices that can deliver corticosteroids directly to the nervous system for the treatment of inflammation associated with neurological disorders, presenting a translatable pathway toward precision nanomedicine approaches for other drugs and diseases.
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Affiliation(s)
- Rafael Crovador
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, New South Wales 2308, Australia.,Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Heidianne Heim
- Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Sophie Cottam
- Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Krishna Feron
- Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Vijay Bhatia
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Fiona Louie
- John Hunter Hospital, New Lambton Heights, New South Wales 2305, Australia
| | - Connor P Sherwood
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, New South Wales 2308, Australia.,Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Paul C Dastoor
- Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Alan M Brichta
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Rebecca Lim
- Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Matthew J Griffith
- Centre for Organic Electronics, University of Newcastle, Callaghan, New South Wales 2308, Australia.,School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Camperdown, New South Wales 2006, Australia
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21
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Le HT, Haque RI, Ouyang Z, Lee SW, Fried SI, Zhao D, Qiu M, Han A. MEMS inductor fabrication and emerging applications in power electronics and neurotechnologies. MICROSYSTEMS & NANOENGINEERING 2021; 7:59. [PMID: 34567771 PMCID: PMC8433479 DOI: 10.1038/s41378-021-00275-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/04/2021] [Accepted: 05/10/2021] [Indexed: 05/08/2023]
Abstract
MEMS inductors are used in a wide range of applications in micro- and nanotechnology, including RF MEMS, sensors, power electronics, and Bio-MEMS. Fabrication technologies set the boundary conditions for inductor design and their electrical and mechanical performance. This review provides a comprehensive overview of state-of-the-art MEMS technologies for inductor fabrication, presents recent advances in 3D additive fabrication technologies, and discusses the challenges and opportunities of MEMS inductors for two emerging applications, namely, integrated power electronics and neurotechnologies. Among the four top-down MEMS fabrication approaches, 3D surface micromachining and through-substrate-via (TSV) fabrication technology have been intensively studied to fabricate 3D inductors such as solenoid and toroid in-substrate TSV inductors. While 3D inductors are preferred for their high-quality factor, high power density, and low parasitic capacitance, in-substrate TSV inductors offer an additional unique advantage for 3D system integration and efficient thermal dissipation. These features make in-substrate TSV inductors promising to achieve the ultimate goal of monolithically integrated power converters. From another perspective, 3D bottom-up additive techniques such as ice lithography have great potential for fabricating inductors with geometries and specifications that are very challenging to achieve with established MEMS technologies. Finally, we discuss inspiring and emerging research opportunities for MEMS inductors.
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Affiliation(s)
- Hoa Thanh Le
- The Rowland Institute at Harvard, Harvard University, Cambridge, MA USA
| | - Rubaiyet I. Haque
- Department of Mechanical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Ziwei Ouyang
- Department of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Seung Woo Lee
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
| | - Shelley I. Fried
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA
- Boston VA Healthcare System, Boston, MA USA
| | - Ding Zhao
- Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, China
- Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou, China
| | - Min Qiu
- Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, China
- Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou, China
| | - Anpan Han
- Department of Mechanical Engineering, Technical University of Denmark, Lyngby, Denmark
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22
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Sun H, Li R, Li H, Weng Z, Wu G, Kerns P, Suib S, Wang X, Zhang Y. Bioinspired Oil-Infused Slippery Surfaces with Water and Ion Barrier Properties. ACS APPLIED MATERIALS & INTERFACES 2021; 13:33464-33476. [PMID: 34241991 DOI: 10.1021/acsami.1c06632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Encapsulation materials play an important role in many applications including wearable electronics, medical devices, underwater robotics, marine skin tagging system, food packaging, and energy conversation and storage devices. To date, all the encapsulation materials, including polymer layers and inorganic materials, are solid materials. These solid materials suffer from limited barrier lifetimes due to pinholes, cracks, and nanopores or from complicated fabrication processes and limited stretchability for interfacing with complex 3D surfaces. This paper reports a solution to this material challenge by demonstrating bioinspired oil-infused slippery surfaces with excellent waterproof property for the first time. A water vapor transmission test shows that locking a thin layer of oil on the silicone elastomer improves the water vapor barrier performance by three orders of magnitude. Accelerated lifetime tests suggest robust water barrier characteristics that approach 226 days at 37 °C even under severe mechanical damage. A combination of temperature- and thickness-dependent experimental measurements and reaction-diffusion modeling reveals the key waterproof property. In addition to serving as a barrier to water, the oil-infused surface demonstrates an attractive ion barrier property. All these exceptional properties suggest the potential applications of slippery surfaces as encapsulation materials for medical devices, underwater electronics, and many others.
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Affiliation(s)
- He Sun
- Department of Biomedical Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Rui Li
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, and International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116024, P.R. China
| | - Huijie Li
- Department of Biomedical Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Zhengyan Weng
- Department of Biomedical Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Guangfu Wu
- Department of Biomedical Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Peter Kerns
- Department of Chemistry, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Steven Suib
- Department of Chemistry, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Xueju Wang
- Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yi Zhang
- Department of Biomedical Engineering, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States
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23
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Datta-Chaudhuri T. Closed-loop neuromodulation will increase the utility of mouse models in Bioelectronic Medicine. Bioelectron Med 2021; 7:10. [PMID: 34193309 PMCID: PMC8244222 DOI: 10.1186/s42234-021-00071-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/01/2021] [Indexed: 01/16/2023] Open
Abstract
Mouse models have been of tremendous benefit to medical science for the better part of a century, yet bioelectronic medicine research using mice has been limited to mostly acute studies because of a lack of tools for chronic stimulation and sensing. A wireless neuromodulation platform small enough for implantation in mice will significantly increase the utility of mouse models in bioelectronic medicine. This perspective examines the necessary functionality of such a system and the technical challenges needed to be overcome for its development. Recent progress is examined and the outlook for the future of implantable devices for mice is discussed.
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Affiliation(s)
- Timir Datta-Chaudhuri
- Institute of Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, NY, 11030, USA. .,Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 500 Hofstra University, Hempstead, NY, 11549, USA.
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24
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Gori M, Vadalà G, Giannitelli SM, Denaro V, Di Pino G. Biomedical and Tissue Engineering Strategies to Control Foreign Body Reaction to Invasive Neural Electrodes. Front Bioeng Biotechnol 2021; 9:659033. [PMID: 34113605 PMCID: PMC8185207 DOI: 10.3389/fbioe.2021.659033] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/27/2021] [Indexed: 12/21/2022] Open
Abstract
Neural-interfaced prostheses aim to restore sensorimotor limb functions in amputees. They rely on bidirectional neural interfaces, which represent the communication bridge between nervous system and neuroprosthetic device by controlling its movements and evoking sensory feedback. Compared to extraneural electrodes (i.e., epineural and perineural implants), intraneural electrodes, implanted within peripheral nerves, have higher selectivity and specificity of neural signal recording and nerve stimulation. However, being implanted in the nerve, their main limitation is represented by the significant inflammatory response that the body mounts around the probe, known as Foreign Body Reaction (FBR), which may hinder their rapid clinical translation. Furthermore, the mechanical mismatch between the consistency of the device and the surrounding neural tissue may contribute to exacerbate the inflammatory state. The FBR is a non-specific reaction of the host immune system to a foreign material. It is characterized by an early inflammatory phase eventually leading to the formation of a fibrotic capsule around intraneural interfaces, which increases the electrical impedance over time and reduces the chronic interface biocompatibility and functionality. Thus, the future in the reduction and control of the FBR relies on innovative biomedical strategies for the fabrication of next-generation neural interfaces, such as the development of more suitable designs of the device with smaller size, appropriate stiffness and novel conductive and biomimetic coatings for improving their long-term stability and performance. Here, we present and critically discuss the latest biomedical approaches from material chemistry and tissue engineering for controlling and mitigating the FBR in chronic neural implants.
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Affiliation(s)
- Manuele Gori
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
- Institute of Biochemistry and Cell Biology (IBBC) - National Research Council (CNR), Rome, Italy
| | - Gianluca Vadalà
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Sara Maria Giannitelli
- Laboratory of Tissue Engineering, Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Vincenzo Denaro
- Laboratory for Regenerative Orthopaedics, Department of Orthopaedic Surgery and Traumatology, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Giovanni Di Pino
- NeXT: Neurophysiology and Neuroengineering of Human-Technology Interaction Research Unit, Università Campus Bio-Medico di Roma, Rome, Italy
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25
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Evaluation methods for long-term reliability of polymer-based implantable biomedical devices. Biomed Eng Lett 2021; 11:97-105. [PMID: 34150346 DOI: 10.1007/s13534-021-00188-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/24/2021] [Accepted: 04/05/2021] [Indexed: 01/04/2023] Open
Abstract
Long-term reliability of implantable biomedical devices is a critical issue for their practical usefulness and successful translation into clinical application. Reliability is particularly of great concern for recently demonstrated devices based on new materials typically relying on polymeric thin films and microfabrication process. While reliability testing protocol has been well-established for traditional metallic packages, common evaluation methods for polymer-based microdevices has yet to be agreed upon, even though various testing methods have been proposed. This article is aiming to summarize the evaluation methods on long-term reliability of emerging biomedical implants based on polymeric thin-films in terms of their theories and implementation with specific focus on difference from the traditional metallic packages.
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26
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Shon A, Brakel K, Hook M, Park H. Fully Implantable Plantar Cutaneous Augmentation System for Rats Using Closed-loop Electrical Nerve Stimulation. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:326-338. [PMID: 33861705 DOI: 10.1109/tbcas.2021.3072894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Plantar cutaneous feedback plays an important role in stable and efficient gait, by modulating the activity of ankle dorsi- and plantar-flexor muscles. However, central and peripheral nervous system trauma often decrease plantar cutaneous feedback and/or interneuronal excitability in processing the plantar cutaneous feedback. In this study, we tested a fully implantable neural recording and stimulation system augmenting plantar cutaneous feedback. Electromyograms were recorded from the medial gastrocnemius muscle for stance phase detection, while biphasic stimulation pulses were applied to the distal-tibial nerve during the stance phase to augment plantar cutaneous feedback. A Bluetooth low energy and a Qi-standard inductive link were adopted for wireless communication and wireless charging, respectively. To test the operation of the system, one intact rat walked on a treadmill with the electrical system implanted into its back. Leg kinematics were recorded to identify the stance phase. Stimulation was applied, with a 250-ms onset delay from stance onset and 200-ms duration, resulting in the onset at 47.58 ± 2.82% of stance phase and the offset at 83.49 ± 4.26% of stance phase (Mean ± SEM). The conduction velocity of the compound action potential (31.2 m/s and 41.6 m/s at 1·T and 2·T, respectively) suggests that the evoked action potential was characteristic of an afferent volley for cutaneous feedback. We also demonstrated successful wireless charging and system reset functions. The experimental results suggest that the presented implantable system can be a valuable neural interface tool to investigate the effect of plantar cutaneous augmentation on gait in a rat model.
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27
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Lei W, Fong NWS, Jarvis KL, McKenzie DR. Quantifying Moisture Penetration in Encapsulated Devices by Heavy Water Mass Spectrometry: A Standard Moisture Leak Using Poly(ether-ether-ketone). ACS APPLIED MATERIALS & INTERFACES 2021; 13:13666-13675. [PMID: 33688725 DOI: 10.1021/acsami.0c23115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Moisture penetration into active biomedical implants such as the bionic ear and eye is a major problem in healthcare since surgery is required to replace devices affected by corrosion. Existing methods for measuring moisture leak rates such as the commercially available dynamic relative humidity method are not sufficiently sensitive to guarantee security against moisture penetration. Helium leak detection is highly sensitive but is challenged by the unknown relation to the moisture leak rate because of mixed flow modes involving liquid water. A standard moisture leak traceable to fundamental units is not currently available, preventing direct comparison of moisture and helium leak rates in the same device. Here, we demonstrate a practical calibrated moisture leak based on the stable polymer poly(ether-ether-ketone), for calibrating heavy water mass spectrometry. Using biomedical test structures from manufactured encapsulations, we show that in the majority of cases, calibrated measurements of molar moisture leak rates exceed the helium leak rate, especially for very small and large leaks. Comparison with theory shows that LaPlace pressure is the driving force for the enhanced moisture flows. We recommend that the compliance limit for helium testing in biomedical devices be reduced by one order of magnitude.
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Affiliation(s)
- Wenwen Lei
- National Measurement Institute, 36 Bradfield Road, West Lindfield, New South Wales 2071, Australia
| | - Nicole W S Fong
- School of Physics, University of Sydney, New South Wales 2006, Australia
| | | | - David R McKenzie
- School of Physics, University of Sydney, New South Wales 2006, Australia
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Abstract
When nerves are damaged by trauma or disease, they are still capable of firing off electrical command signals that originate from the brain. Furthermore, those damaged nerves have an innate ability to partially regenerate, so they can heal from trauma and even reinnervate new muscle targets. For an amputee who has his/her damaged nerves surgically reconstructed, the electrical signals that are generated by the reinnervated muscle tissue can be sensed and interpreted with bioelectronics to control assistive devices or robotic prostheses. No two amputees will have identical physiologies because there are many surgical options for reconstructing residual limbs, which may in turn impact how well someone can interface with a robotic prosthesis later on. In this review, we aim to investigate what the literature has to say about different pathways for peripheral nerve regeneration and how each pathway can impact the neuromuscular tissue’s final electrophysiology. This information is important because it can guide us in planning the development of future bioelectronic devices, such as prosthetic limbs or neurostimulators. Future devices will primarily have to interface with tissue that has undergone some natural regeneration process, and so we have explored and reported here what is known about the bioelectrical features of neuromuscular tissue regeneration.
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29
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Mousavi M, Ghaleh H, Jalili K, Abbasi F. Multi-layer PDMS films having antifouling property for biomedical applications. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2020; 32:678-693. [PMID: 33250001 DOI: 10.1080/09205063.2020.1856300] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Poly(dimethylsiloxane) (PDMS) elastomer is now a well-known material for packaging implantable biomedical micro-devices owing to unique bulk properties such as biocompatibility, low toxicity, excellent rheological properties, good flexibility, and mechanical stability. Despite the desirable bulk characteristics, PDMS is generally regarded as a high-flux material for oxygen and water vapor to penetrate compared with other polymeric barrier materials, which is related to the defect-induced penetration through the packaging coating prepared by the traditional deposition techniques. Besides, its hydrophobic nature causes serious fouling problems and limits the practical application of PDMS-based devices. In this work, the performance of silicone thin films as a packaging layer was improved by the fabrication of the roller-casted multiple thin layers to minimize a defect-induced failure. To confer hydrophilicity and cell fouling resistance, high-density and well-defined poly(oligo(ethylene glycol) methacrylate) (POEGMA) brushes were tethered via the surface-initiated atom transfer radical polymerization (SI-ATRP) technique on the roller-casted multiple thin PDMS layers. The characteristics of fabricated substrates were determined by static water contact angle measurement, X-ray photoelectron spectroscopy, and attenuated total reflection-Fourier transform infrared spectroscopy. In vitro cell behavior of POEGMA-grafted PDMS substrates was evaluated to examine cell-fouling resistance.
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Affiliation(s)
- M Mousavi
- Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran.,Faculty of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
| | - H Ghaleh
- Department of Polymer Science and Engineering, University of Bonab, Bonab, Iran
| | - K Jalili
- Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran.,Faculty of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
| | - F Abbasi
- Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran.,Faculty of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
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30
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Zhao J, Ghannam R, Htet KO, Liu Y, Law M, Roy VAL, Michel B, Imran MA, Heidari H. Self-Powered Implantable Medical Devices: Photovoltaic Energy Harvesting Review. Adv Healthc Mater 2020; 9:e2000779. [PMID: 32729228 DOI: 10.1002/adhm.202000779] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/09/2020] [Indexed: 12/21/2022]
Abstract
Implantable technologies are becoming more widespread for biomedical applications that include physical identification, health diagnosis, monitoring, recording, and treatment of human physiological traits. However, energy harvesting and power generation beneath the human tissue are still a major challenge. In this regard, self-powered implantable devices that scavenge energy from the human body are attractive for long-term monitoring of human physiological traits. Thanks to advancements in material science and nanotechnology, energy harvesting techniques that rely on piezoelectricity, thermoelectricity, biofuel, and radio frequency power transfer are emerging. However, all these techniques suffer from limitations that include low power output, bulky size, or low efficiency. Photovoltaic (PV) energy conversion is one of the most promising candidates for implantable applications due to their higher-power conversion efficiencies and small footprint. Herein, the latest implantable energy harvesting technologies are surveyed. A comparison between the different state-of-the-art power harvesting methods is also provided. Finally, recommendations are provided regarding the feasibility of PV cells as an in vivo energy harvester, with an emphasis on skin penetration, fabrication, encapsulation, durability, biocompatibility, and power management.
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Affiliation(s)
- Jinwei Zhao
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
| | - Rami Ghannam
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
| | - Kaung Oo Htet
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
| | - Yuchi Liu
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
| | - Man‐kay Law
- State Key Laboratory of Analog and Mixed‐Signal VLSI AMSV University of Macao Macao China
| | | | - Bruno Michel
- Smart System Integration IBM Research GmbH Rueschlikon CH‐8803 Switzerland
| | - Muhammad Ali Imran
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
| | - Hadi Heidari
- James Watts school of Engineering University of Glasgow Glasgow G12 8QQ UK
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31
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Shim S, Seo K, Kim SJ. A preliminary implementation of an active intraocular prosthesis as a new image acquisition device for a cortical visual prosthesis. J Artif Organs 2020; 23:262-269. [PMID: 32342231 DOI: 10.1007/s10047-020-01168-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/07/2020] [Indexed: 11/30/2022]
Abstract
An active intraocular prosthesis is herein proposed as a new image acquisition device for a cortical visual prosthesis. A conventional intraocular prosthesis is a passive device that helps blind patients underwent eye enucleation to maintain the shape of an eyeball. In contrast, an active intraocular prosthesis, which works as an implantable wireless camera, can capture real-time images and transmit them to a cortical visual prosthesis to restore partial vision of the patients. This active device has distinct advantages in that it can garner a variety of image information while focusing on objects in accordance with natural eye movements, compared with a glasses-mounted camera and implanted micro-photodiodes in typical artificial vision systems. Coated with an epoxy and sealed by an elastomer for biocompatibility as well as durability, the active intraocular prosthesis was fabricated in a spherical form miniaturized enough to be inserted into the eye. Its operation was evaluated by wireless image acquisition displaying a processed gray-scale image. Furthermore, signal-to-noise ratio measurements were conducted to find a reliable communication range of the fabricated prosthesis, while it was covered by an 8-mm-thick biological medium that mimicked in vivo environments. In conclusion, the feasibility of the active intraocular prosthesis to cooperate with a cortical visual prosthesis is discussed.
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Affiliation(s)
- Shinyong Shim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul, 08826, South Korea.,Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, South Korea
| | - Kangmoon Seo
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul, 08826, South Korea
| | - Sung June Kim
- Department of Electrical and Computer Engineering, College of Engineering, Seoul National University, Seoul, 08826, South Korea. .,Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, South Korea. .,Institute on Aging, College of Medicine, Seoul National University, Seoul, 08826, South Korea.
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32
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Chong H, Majerus SJ, Bogie KM, Zorman CA. Non‐hermetic packaging of biomedical microsystems from a materials perspective: A review. ACTA ACUST UNITED AC 2020. [DOI: 10.1002/mds3.10082] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Hao Chong
- Department of Electrical, Computer, and Systems Engineering Case Western Reserve University Cleveland OH USA
| | | | - Kath M. Bogie
- APT Center Louis Stokes VA Medical Center Cleveland OH USA
- Department of Orthopaedics Case Western Reserve University School of Medicine Cleveland OH USA
| | - Christian A. Zorman
- Department of Electrical, Computer, and Systems Engineering Case Western Reserve University Cleveland OH USA
- APT Center Louis Stokes VA Medical Center Cleveland OH USA
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33
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Accelerated Hermeticity Testing of Biocompatible Moisture Barriers Used for the Encapsulation of Implantable Medical Devices. COATINGS 2019. [DOI: 10.3390/coatings10010019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Barrier layers for the long-term encapsulation of implantable medical devices play a crucial role in the devices’ performance and reliability. Typically, to understand the stability and predict the lifetime of barriers (therefore, the implantable devices), the device is subjected to accelerated testing at higher temperatures compared to its service parameters. Nevertheless, at high temperatures, reaction and degradation mechanisms might be different, resulting in false accelerated test results. In this study, the maximum valid temperatures for the accelerated testing of two barrier layers were investigated: atomic layer deposited (ALD) Al2O3 and stacked ALD HfO2/Al2O3/HfO2, hereinafter referred to as ALD-3. The in-house developed standard barrier performance test is based on continuous electrical resistance monitoring and microscopic inspection of Cu patterns covered with the barrier and immersed in phosphate buffered saline (PBS) at temperatures up to 95 °C. The results demonstrate the valid temperature window to perform temperature acceleration tests. In addition, the optimized ALD layer in combination with polyimide (polyimide/ALD-3/polyimide) works as effective barrier at 60 °C for 1215 days, suggesting the potential applicability to the encapsulation of long-term implants.
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34
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Ultra-Long-Term Reliable Encapsulation Using an Atomic Layer Deposited HfO2/Al2O3/HfO2 Triple-Interlayer for Biomedical Implants. COATINGS 2019. [DOI: 10.3390/coatings9090579] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term packaging of miniaturized, flexible implantable medical devices is essential for the next generation of medical devices. Polymer materials that are biocompatible and flexible have attracted extensive interest for the packaging of implantable medical devices, however realizing these devices with long-term hermeticity up to several years remains a great challenge. Here, polyimide (PI) based hermetic encapsulation was greatly improved by atomic layer deposition (ALD) of a nanoscale-thin, biocompatible sandwich stack of HfO2/Al2O3/HfO2 (ALD-3) between two polyimide layers. A thin copper film covered with a PI/ALD-3/PI barrier maintained excellent electrochemical performance over 1028 days (2.8 years) during acceleration tests at 60 °C in phosphate buffered saline solution (PBS). This stability is equivalent to approximately 14 years at 37 °C. The coatings were monitored in situ through electrochemical impedance spectroscopy (EIS), were inspected by microscope, and were further analyzed using equivalent circuit modeling. The failure mode of ALD Al2O3, ALD-3, and PI soaking in PBS is discussed. Encapsulation using ultrathin ALD-3 combined with PI for the packaging of implantable medical devices is robust at the acceleration temperature condition for more than 2.8 years, showing that it has great potential as reliable packaging for long-term implantable devices.
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