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Xiang Y, Zhao Y, Cheng T, Sun S, Wang J, Pei R. Implantable Neural Microelectrodes: How to Reduce Immune Response. ACS Biomater Sci Eng 2024; 10:2762-2783. [PMID: 38591141 DOI: 10.1021/acsbiomaterials.4c00238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Implantable neural microelectrodes exhibit the great ability to accurately capture the electrophysiological signals from individual neurons with exceptional submillisecond precision, holding tremendous potential for advancing brain science research, as well as offering promising avenues for neurological disease therapy. Although significant advancements have been made in the channel and density of implantable neural microelectrodes, challenges persist in extending the stable recording duration of these microelectrodes. The enduring stability of implanted electrode signals is primarily influenced by the chronic immune response triggered by the slight movement of the electrode within the neural tissue. The intensity of this immune response increases with a higher bending stiffness of the electrode. This Review thoroughly analyzes the sequential reactions evoked by implanted electrodes in the brain and highlights strategies aimed at mitigating chronic immune responses. Minimizing immune response mainly includes designing the microelectrode structure, selecting flexible materials, surface modification, and controlling drug release. The purpose of this paper is to provide valuable references and ideas for reducing the immune response of implantable neural microelectrodes and stimulate their further exploration in the field of brain science.
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Affiliation(s)
- Ying Xiang
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, PR China
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Yuewu Zhao
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Tingting Cheng
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Shengkai Sun
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
| | - Jine Wang
- Jiangxi Institute of Nanotechnology, Nanchang 330200, China
- College of Medicine and Nursing, Shandong Provincial Engineering Laboratory of Novel Pharmaceutical Excipients, Sustained and Controlled Release Preparations, Dezhou University, Dezhou 253023, China
| | - Renjun Pei
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, PR China
- CAS Key Laboratory of Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
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2
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Bianchi M, De Salvo A, Asplund M, Carli S, Di Lauro M, Schulze‐Bonhage A, Stieglitz T, Fadiga L, Biscarini F. Poly(3,4-ethylenedioxythiophene)-Based Neural Interfaces for Recording and Stimulation: Fundamental Aspects and In Vivo Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104701. [PMID: 35191224 PMCID: PMC9036021 DOI: 10.1002/advs.202104701] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/04/2022] [Indexed: 05/29/2023]
Abstract
Next-generation neural interfaces for bidirectional communication with the central nervous system aim to achieve the intimate integration with the neural tissue with minimal neuroinflammatory response, high spatio-temporal resolution, very high sensitivity, and readout stability. The design and manufacturing of devices for low power/low noise neural recording and safe and energy-efficient stimulation that are, at the same time, conformable to the brain, with matched mechanical properties and biocompatibility, is a convergence area of research where neuroscientists, materials scientists, and nanotechnologists operate synergically. The biotic-abiotic neural interface, however, remains a formidable challenge that prompts for new materials platforms and innovation in device layouts. Conductive polymers (CP) are attractive materials to be interfaced with the neural tissue and to be used as sensing/stimulating electrodes because of their mixed ionic-electronic conductivity, their low contact impedance, high charge storage capacitance, chemical versatility, and biocompatibility. This manuscript reviews the state-of-the-art of poly(3,4-ethylenedioxythiophene)-based neural interfaces for extracellular recording and stimulation, focusing on those technological approaches that are successfully demonstrated in vivo. The aim is to highlight the most reliable and ready-for-clinical-use solutions, in terms of materials technology and recording performance, other than spot major limitations and identify future trends in this field.
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Affiliation(s)
- Michele Bianchi
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Anna De Salvo
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Maria Asplund
- Division of Nursing and Medical TechnologyLuleå University of TechnologyLuleå971 87Sweden
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Stefano Carli
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Present address:
Department of Environmental and Prevention SciencesUniversità di FerraraFerrara44121Italy
| | - Michele Di Lauro
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
| | - Andreas Schulze‐Bonhage
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
- Epilepsy CenterFaculty of MedicineUniversity of FreiburgFreiburg79110Germany
| | - Thomas Stieglitz
- Department of Microsystems Engineering‐IMTEKUniversity of FreiburgFreiburg79110Germany
- BrainLinks‐BrainTools CenterUniversity of FreiburgFreiburg79110Germany
| | - Luciano Fadiga
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Sezione di FisiologiaUniversità di Ferraravia Fossato di Mortara 17Ferrara44121Italy
| | - Fabio Biscarini
- Center for Translational Neurophysiology of Speech and CommunicationFondazione Istituto Italiano di Tecnologiavia Fossato di Mortara 17Ferrara44121Italy
- Life Science DepartmentUniversità di Modena e Reggio EmiliaVia Campi 103Modena41125Italy
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3
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Hyakumura T, Aregueta-Robles U, Duan W, Villalobos J, Adams WK, Poole-Warren L, Fallon JB. Improving Deep Brain Stimulation Electrode Performance in vivo Through Use of Conductive Hydrogel Coatings. Front Neurosci 2021; 15:761525. [PMID: 34803592 PMCID: PMC8602793 DOI: 10.3389/fnins.2021.761525] [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: 08/20/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Active implantable neurological devices like deep brain stimulators have been used over the past few decades to treat movement disorders such as those in people with Parkinson’s disease and more recently, in psychiatric conditions like obsessive compulsive disorder. Electrode-tissue interfaces that support safe and effective targeting of specific brain regions are critical to success of these devices. Development of directional electrodes that activate smaller volumes of brain tissue requires electrodes to operate safely with higher charge densities. Coatings such as conductive hydrogels (CHs) provide lower impedances and higher charge injection limits (CILs) than standard platinum electrodes and support safer application of smaller electrode sizes. The aim of this study was to examine the chronic in vivo performance of a new low swelling CH coating that supports higher safe charge densities than traditional platinum electrodes. A range of hydrogel blends were engineered and their swelling and electrical performance compared. Electrochemical performance and stability of high and low swelling formulations were compared during insertion into a model brain in vitro and the formulation with lower swelling characteristics was chosen for the in vivo study. CH-coated or uncoated Pt electrode arrays were implanted into the brains of 14 rats, and their electrochemical performance was tested weekly for 8 weeks. Tissue response and neural survival was assessed histologically following electrode array removal. CH coating resulted in significantly lower voltage transient impedance, higher CIL, lower electrochemical impedance spectroscopy, and higher charge storage capacity compared to uncoated Pt electrodes in vivo, and this advantage was maintained over the 8-week implantation. There was no significant difference in evoked potential thresholds, signal-to-noise ratio, tissue response or neural survival between CH-coated and uncoated Pt groups. The significant electrochemical advantage and stability of CH coating in the brain supports the suitability of this coating technology for future development of smaller, higher fidelity electrode arrays with higher charge density requirement.
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Affiliation(s)
- Tomoko Hyakumura
- The Bionics Institute of Australia, East Melbourne, VIC, Australia.,Department of Medical Bionics, The University of Melbourne, Parkville, VIC, Australia
| | - Ulises Aregueta-Robles
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Wenlu Duan
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Joel Villalobos
- The Bionics Institute of Australia, East Melbourne, VIC, Australia.,Department of Medical Bionics, The University of Melbourne, Parkville, VIC, Australia
| | - Wendy K Adams
- The Bionics Institute of Australia, East Melbourne, VIC, Australia
| | - Laura Poole-Warren
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW, Australia.,Tyree Foundation Institute of Health Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - James B Fallon
- The Bionics Institute of Australia, East Melbourne, VIC, Australia.,Department of Medical Bionics, The University of Melbourne, Parkville, VIC, Australia
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4
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Elyahoodayan S, Jiang W, Lee CD, Shao X, Weiland G, Whalen JJ, Petrossians A, Song D. Stimulation and Recording of the Hippocampus Using the Same Pt-Ir Coated Microelectrodes. Front Neurosci 2021; 15:616063. [PMID: 33716647 PMCID: PMC7943859 DOI: 10.3389/fnins.2021.616063] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 01/28/2021] [Indexed: 01/11/2023] Open
Abstract
Same-electrode stimulation and recording with high spatial resolution, signal quality, and power efficiency is highly desirable in neuroscience and neural engineering. High spatial resolution and signal-to-noise ratio is necessary for obtaining unitary activities and delivering focal stimulations. Power efficiency is critical for battery-operated implantable neural interfaces. This study demonstrates the capability of recording single units as well as evoked potentials in response to a wide range of electrochemically safe stimulation pulses through high-resolution microelectrodes coated with co-deposition of Pt-Ir. It also compares signal-to-noise ratio, single unit activity, and power efficiencies between Pt-Ir coated and uncoated microelectrodes. To enable stimulation and recording with the same microelectrodes, microelectrode arrays were treated with electrodeposited platinum-iridium coating (EPIC) and tested in the CA1 cell body layer of rat hippocampi. The electrodes' ability to (1) inject a large range of electrochemically reversable stimulation pulses to the tissue, and (2) record evoked potentials and single unit activities were quantitively assessed over an acute time period. Compared to uncoated electrodes, EPIC electrodes recorded signals with higher signal-to-noise ratios (coated: 9.77 ± 1.95 dB; uncoated: 1.95 ± 0.40 dB) and generated lower voltages (coated: 100 mV; uncoated: 650 mV) for a given stimulus (5 μA). The improved performance corresponded to lower energy consumptions and electrochemically safe stimulation above 5 μA (>0.38 mC/cm2), which enabled elicitation of field excitatory post synaptic potentials and population spikes. Spontaneous single unit activities were also modulated by varying stimulation intensities and monitored through the same electrodes. This work represents an example of stimulation and recording single unit activities from the same microelectrode, which provides a powerful tool for monitoring and manipulating neural circuits at the single neuron level.
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Affiliation(s)
- Sahar Elyahoodayan
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Wenxuan Jiang
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | | | - Xiecheng Shao
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | | | | | | | - Dong Song
- Department of Biomedical Engineering, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States
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5
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A 3D-CNT micro-electrode array for zebrafish ECG study including directionality measurement and drug test. Biocybern Biomed Eng 2020. [DOI: 10.1016/j.bbe.2020.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Yang W, Gong Y, Li W. A Review: Electrode and Packaging Materials for Neurophysiology Recording Implants. Front Bioeng Biotechnol 2020; 8:622923. [PMID: 33585422 PMCID: PMC7873964 DOI: 10.3389/fbioe.2020.622923] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/10/2020] [Indexed: 01/28/2023] Open
Abstract
To date, a wide variety of neural tissue implants have been developed for neurophysiology recording from living tissues. An ideal neural implant should minimize the damage to the tissue and perform reliably and accurately for long periods of time. Therefore, the materials utilized to fabricate the neural recording implants become a critical factor. The materials of these devices could be classified into two broad categories: electrode materials as well as packaging and substrate materials. In this review, inorganic (metals and semiconductors), organic (conducting polymers), and carbon-based (graphene and carbon nanostructures) electrode materials are reviewed individually in terms of various neural recording devices that are reported in recent years. Properties of these materials, including electrical properties, mechanical properties, stability, biodegradability/bioresorbability, biocompatibility, and optical properties, and their critical importance to neural recording quality and device capabilities, are discussed. For the packaging and substrate materials, different material properties are desired for the chronic implantation of devices in the complex environment of the body, such as biocompatibility and moisture and gas hermeticity. This review summarizes common solid and soft packaging materials used in a variety of neural interface electrode designs, as well as their packaging performances. Besides, several biopolymers typically applied over the electrode package to reinforce the mechanical rigidity of devices during insertion, or to reduce the immune response and inflammation at the device-tissue interfaces are highlighted. Finally, a benchmark analysis of the discussed materials and an outlook of the future research trends are concluded.
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Affiliation(s)
- Weiyang Yang
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Yan Gong
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
| | - Wen Li
- Microtechnology Lab, Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI, United States
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7
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Xiao G, Song Y, Zhang Y, Xu S, Xing Y, Wang M, Cai X. Platinum/Graphene Oxide Coated Microfabricated Arrays for Multinucleus Neural Activities Detection in the Rat Models of Parkinson’s Disease Treated by Apomorphine. ACS APPLIED BIO MATERIALS 2019; 2:4010-4019. [DOI: 10.1021/acsabm.9b00541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Guihua Xiao
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Zhang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shengwei Xu
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yu Xing
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Mixia Wang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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8
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Harris AR, Allitt BJ, Paolini AG. Predicting neural recording performance of implantable electrodes. Analyst 2019; 144:2973-2983. [PMID: 30888346 DOI: 10.1039/c8an02214c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recordings of neural activity can be used to aid communication, control prosthetic devices or alleviate disease symptoms. Chronic recordings require a high signal-to-noise ratio that is stable for years. Current cortical devices generally fail within months to years after implantation. Development of novel devices to increase lifetime requires valid testing protocols and a knowledge of the critical parameters controlling electrophysiological performance. Here we present electrochemical and electrophysiological protocols for assessing implantable electrodes. Biological noise from neural recording has significant impact on signal-to-noise ratio. A recently developed surgical approach was utilised to reduce biological noise. This allowed correlation of electrochemical and electrophysiological behaviour. The impedance versus frequency of modified electrodes was non-linear. It was found that impedance at low frequencies was a stronger predictor of electrophysiological performance than the typically reported impedance at 1 kHz. Low frequency impedance is a function of electrode area, and a strong correlation of electrode area with electrophysiological response was also seen. Use of these standardised testing protocols will allow future devices to be compared before transfer to preclinical and clinical trials.
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Affiliation(s)
- Alexander R Harris
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, NSW 2522, Australia.
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9
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Gulino M, Kim D, Pané S, Santos SD, Pêgo AP. Tissue Response to Neural Implants: The Use of Model Systems Toward New Design Solutions of Implantable Microelectrodes. Front Neurosci 2019; 13:689. [PMID: 31333407 PMCID: PMC6624471 DOI: 10.3389/fnins.2019.00689] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 06/18/2019] [Indexed: 01/28/2023] Open
Abstract
The development of implantable neuroelectrodes is advancing rapidly as these tools are becoming increasingly ubiquitous in clinical practice, especially for the treatment of traumatic and neurodegenerative disorders. Electrodes have been exploited in a wide number of neural interface devices, such as deep brain stimulation, which is one of the most successful therapies with proven efficacy in the treatment of diseases like Parkinson or epilepsy. However, one of the main caveats related to the clinical application of electrodes is the nervous tissue response at the injury site, characterized by a cascade of inflammatory events, which culminate in chronic inflammation, and, in turn, result in the failure of the implant over extended periods of time. To overcome current limitations of the most widespread macroelectrode based systems, new design strategies and the development of innovative materials with superior biocompatibility characteristics are currently being investigated. This review describes the current state of the art of in vitro, ex vivo, and in vivo models available for the study of neural tissue response to implantable microelectrodes. We particularly highlight new models with increased complexity that closely mimic in vivo scenarios and that can serve as promising alternatives to animal studies for investigation of microelectrodes in neural tissues. Additionally, we also express our view on the impact of the progress in the field of neural tissue engineering on neural implant research.
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Affiliation(s)
- Maurizio Gulino
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB – Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
- FEUP – Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
| | - Donghoon Kim
- Multi-Scale Robotics Lab (MSRL), Institute of Robotics and Intelligent Systems (IRIS), ETH Zurich, Zurich, Switzerland
| | - Salvador Pané
- Multi-Scale Robotics Lab (MSRL), Institute of Robotics and Intelligent Systems (IRIS), ETH Zurich, Zurich, Switzerland
| | - Sofia Duque Santos
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB – Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
| | - Ana Paula Pêgo
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- INEB – Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
- FEUP – Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
- ICBAS – Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
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10
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Lee M, Shim HJ, Choi C, Kim DH. Soft High-Resolution Neural Interfacing Probes: Materials and Design Approaches. NANO LETTERS 2019; 19:2741-2749. [PMID: 31002760 DOI: 10.1021/acs.nanolett.8b04895] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Neural interfacing probes are located between the nervous system and the implanted electronic device in order to acquire information on the complex neuronal activity and to reconstruct impaired neural connectivity. Despite remarkable advancement in recent years, conventional neural interfacing is still unable to completely accomplish these goals, especially in long-term brain interfacing. The major limitation arises from physical and mechanical differences between neural interfacing probes and neural tissues that cause local immune responses and production of scar cells near the interface. Therefore, neural interfaces should ideally be extremely soft and have the physical scale of cells to mitigate the boundary between biotic and abiotic systems. Soft materials for neural interfaces have been intensively investigated to improve both interfacing and long-term signal transmission. The design and fabrication of micro and nanoscale devices have drastically decreased the stiffness of probes and enabled single-neuron measurement. In this Mini Review, we discuss materials and design approaches for developing soft high-resolution neural probes intended for long-term brain interfacing and outline existent challenges for achieving next-generation neural interfacing probes.
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Affiliation(s)
- Mincheol Lee
- Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea
- School of Chemical and Biological Engineering, Institute of Chemical Processes , Seoul National University , Seoul 08826 , Republic of Korea
| | - Hyung Joon Shim
- Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea
- School of Chemical and Biological Engineering, Institute of Chemical Processes , Seoul National University , Seoul 08826 , Republic of Korea
| | - Changsoon Choi
- Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea
- School of Chemical and Biological Engineering, Institute of Chemical Processes , Seoul National University , Seoul 08826 , Republic of Korea
| | - Dae-Hyeong Kim
- Center for Nanoparticle Research , Institute for Basic Science (IBS) , Seoul 08826 , Republic of Korea
- School of Chemical and Biological Engineering, Institute of Chemical Processes , Seoul National University , Seoul 08826 , Republic of Korea
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11
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Berggren M, Crispin X, Fabiano S, Jonsson MP, Simon DT, Stavrinidou E, Tybrandt K, Zozoulenko I. Ion Electron-Coupled Functionality in Materials and Devices Based on Conjugated Polymers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805813. [PMID: 30620417 DOI: 10.1002/adma.201805813] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/16/2018] [Indexed: 05/23/2023]
Abstract
The coupling between charge accumulation in a conjugated polymer and the ionic charge compensation, provided from an electrolyte, defines the mode of operation in a vast array of different organic electrochemical devices. The most explored mixed organic ion-electron conductor, serving as the active electrode in these devices, is poly(3,4-ethyelenedioxythiophene) doped with polystyrelensulfonate (PEDOT:PSS). In this progress report, scientists of the Laboratory of Organic Electronics at Linköping University review some of the achievements derived over the last two decades in the field of organic electrochemical devices, in particular including PEDOT:PSS as the active material. The recently established understanding of the volumetric capacitance and the mixed ion-electron charge transport properties of PEDOT are described along with examples of various devices and phenomena utilizing this ion-electron coupling, such as the organic electrochemical transistor, ionic-electronic thermodiffusion, electrochromic devices, surface switches, and more. One of the pioneers in this exciting research field is Prof. Olle Inganäs and the authors of this progress report wish to celebrate and acknowledge all the fantastic achievements and inspiration accomplished by Prof. Inganäs all since 1981.
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Affiliation(s)
- Magnus Berggren
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Xavier Crispin
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Simone Fabiano
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Magnus P Jonsson
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Daniel T Simon
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Eleni Stavrinidou
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Klas Tybrandt
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
| | - Igor Zozoulenko
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden
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12
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Lee D, Moon HC, Tran BT, Kwon DH, Kim YH, Jung SD, Joo JH, Park YS. Characterization of Tetrodes Coated with Au Nanoparticles (AuNPs) and PEDOT and Their Application to Thalamic Neural Signal Detection in vivo. Exp Neurobiol 2019; 27:593-604. [PMID: 30636908 PMCID: PMC6318560 DOI: 10.5607/en.2018.27.6.593] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/12/2018] [Accepted: 11/16/2018] [Indexed: 11/27/2022] Open
Abstract
Tetrodes, consisting of four twisted micro-wires can simultaneously record the number of neurons in the brain. To improve the quality of neuronal activity detection, the tetrode tips should be modified to increase the surface area and lower the impedance properties. In this study, tetrode tips were modified by the electrodeposition of Au nanoparticles (AuNPs) and dextran (Dex) doped poly (3,4-ethylenedioxythiophene) (PEDOT). The electrochemical properties were measured using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A decrease in the impedance value from 4.3 MΩ to 13 kΩ at 1 kHz was achieved by the modified tetrodes. The cathodic charge storage capacity (CSCC) of AuNPs-PEDOT deposited tetrodes was 4.5 mC/cm2, as determined by CV measurements. The tetrodes that were electroplated with AuNPs and PEDOT exhibited an increased surface area, which reduced the tetrode impedance. In vivo recording in the ventral posterior medial (VPM) nucleus of the thalamus was performed to investigate the single-unit activity in normal rats. To evaluate the recording performance of modified tetrodes, spontaneous spike signals were recorded. The values of the L-ratio, isolation distance and signal-to-noise (SNR) confirmed that electroplating the tetrode surface with AuNPs and PEDOT improved the recording performance, and these parameters could be used to effectively quantify the spikes of each cluster.
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Affiliation(s)
- Daae Lee
- Department of Advanced Materials Engineering, Chungbuk National University, Cheongju 28644, Korea
| | - Hyeong Cheol Moon
- Department of Neurosurgery, Chungbuk National University Hospital, Cheongju 28644, Korea.,Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
| | - Bao-Tram Tran
- Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
| | - Dae-Hyuk Kwon
- Neuroscience Research Institute, Brain-Bio center, University of Suwon, Hwaseong 18323, Korea
| | - Yong Hee Kim
- Synaptic Devices Research Section, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Sang-Don Jung
- Synaptic Devices Research Section, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Jong Hoon Joo
- Department of Advanced Materials Engineering, Chungbuk National University, Cheongju 28644, Korea
| | - Young Seok Park
- Department of Neurosurgery, Chungbuk National University Hospital, Cheongju 28644, Korea.,Department of Neurosurgery, Chungbuk National University, Cheongju 28644, Korea
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13
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Suarez-Perez A, Gabriel G, Rebollo B, Illa X, Guimerà-Brunet A, Hernández-Ferrer J, Martínez MT, Villa R, Sanchez-Vives MV. Quantification of Signal-to-Noise Ratio in Cerebral Cortex Recordings Using Flexible MEAs With Co-localized Platinum Black, Carbon Nanotubes, and Gold Electrodes. Front Neurosci 2018; 12:862. [PMID: 30555290 PMCID: PMC6282047 DOI: 10.3389/fnins.2018.00862] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 11/05/2018] [Indexed: 11/25/2022] Open
Abstract
Developing new standardized tools to characterize brain recording devices is critical to evaluate neural probes and for translation to clinical use. The signal-to-noise ratio (SNR) measurement is the gold standard for quantifying the performance of brain recording devices. Given the drawbacks with the SNR measure, our first objective was to devise a new method to calculate the SNR of neural signals to distinguish signal from noise. Our second objective was to apply this new SNR method to evaluate electrodes of three different materials (platinum black, Pt; carbon nanotubes, CNTs; and gold, Au) co-localized in tritrodes to record from the same cortical area using specifically designed multielectrode arrays. Hence, we devised an approach to calculate SNR at different frequencies based on the features of cortical slow oscillations (SO). Since SO consist in the alternation of silent periods (Down states) and active periods (Up states) of neuronal activity, we used these as noise and signal, respectively. The spectral SNR was computed as the power spectral density (PSD) of Up states (signal) divided by the PSD of Down states (noise). We found that Pt and CNTs electrodes have better recording performance than Au electrodes for the explored frequency range (5–1500 Hz). Together with two proposed SNR estimators for the lower and upper frequency limits, these results substantiate our SNR calculation at different frequency bands. Our results provide a new validated SNR measure that provides rich information of the performance of recording devices at different brain activity frequency bands (<1500 Hz).
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Affiliation(s)
- Alex Suarez-Perez
- Systems Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Gemma Gabriel
- Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica, Consejo Superior de Investigaciones Científicas, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Madrid, Spain
| | - Beatriz Rebollo
- Systems Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Xavi Illa
- Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica, Consejo Superior de Investigaciones Científicas, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Madrid, Spain
| | - Anton Guimerà-Brunet
- Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica, Consejo Superior de Investigaciones Científicas, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Madrid, Spain
| | | | - Maria Teresa Martínez
- Instituto de Carboquímica, Consejo Superior de Investigaciones Científicas, Zaragoza, Spain
| | - Rosa Villa
- Instituto de Microelectrónica de Barcelona, Centro Nacional de Microelectrónica, Consejo Superior de Investigaciones Científicas, Barcelona, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, Madrid, Spain
| | - Maria V Sanchez-Vives
- Systems Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,ICREA, Barcelona, Spain
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14
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Neto JP, Baião P, Lopes G, Frazão J, Nogueira J, Fortunato E, Barquinha P, Kampff AR. Does Impedance Matter When Recording Spikes With Polytrodes? Front Neurosci 2018; 12:715. [PMID: 30349453 PMCID: PMC6188074 DOI: 10.3389/fnins.2018.00715] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/19/2018] [Indexed: 11/29/2022] Open
Abstract
Extracellular microelectrodes have been widely used to measure brain activity, yet there are still basic questions about the requirements for a good extracellular microelectrode. One common source of confusion is how much an electrode's impedance affects the amplitude of extracellular spikes and background noise. Here we quantify the effect of an electrode's impedance on data quality in extracellular recordings, which is crucial for both the detection of spikes and their assignment to the correct neurons. This study employs commercial polytrodes containing 32 electrodes (177 μm2) arranged in a dense array. This allowed us to directly compare, side-by-side, the same extracellular signals measured by modified low impedance (∼100 kΩ) microelectrodes with unmodified high impedance (∼1 MΩ) microelectrodes. We begin with an evaluation of existing protocols to lower the impedance of the electrodes. The poly (3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS) electrodeposition protocol is a simple, stable, and reliable method for decreasing the impedance of a microelectrode up to 10-fold. We next record in vivo using polytrodes that are modified in a 'chess board' pattern, such that the signal of one neuron is detected by multiple coated and non-coated electrodes. The performance of the coated and non-coated electrodes is then compared on measures of background noise and amplitude of the detected action potentials. If the proper recording system is used, then the impedance of a microelectrode within the range of standard polytrodes (∼0.1 to 2 MΩ) does not greatly affect data quality and spike sorting. This study should encourage neuroscientists to stop worrying about one more unknown.
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Affiliation(s)
- Joana P. Neto
- CENIMAT/I3N and CEMOP/Uninova, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
- Sainsbury Wellcome Centre, University College London, London, United Kingdom
| | - Pedro Baião
- CENIMAT/I3N and CEMOP/Uninova, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Gonçalo Lopes
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - João Frazão
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Joana Nogueira
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Elvira Fortunato
- CENIMAT/I3N and CEMOP/Uninova, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Pedro Barquinha
- CENIMAT/I3N and CEMOP/Uninova, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Adam R. Kampff
- Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal
- Sainsbury Wellcome Centre, University College London, London, United Kingdom
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15
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Kim T, Cho M, Yu KJ. Flexible and Stretchable Bio-Integrated Electronics Based on Carbon Nanotube and Graphene. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E1163. [PMID: 29986539 PMCID: PMC6073353 DOI: 10.3390/ma11071163] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/30/2018] [Accepted: 07/06/2018] [Indexed: 11/23/2022]
Abstract
Scientific and engineering progress associated with increased interest in healthcare monitoring, therapy, and human-machine interfaces has rapidly accelerated the development of bio-integrated multifunctional devices. Recently, compensation for the cons of existing materials on electronics for health care systems has been provided by carbon-based nanomaterials. Due to their excellent mechanical and electrical properties, these materials provide benefits such as improved flexibility and stretchability for conformal integration with the soft, curvilinear surfaces of human tissues or organs, while maintaining their own unique functions. This review summarizes the most recent advanced biomedical devices and technologies based on two most popular carbon based materials, carbon nanotubes (CNTs) and graphene. In the beginning, we discuss the biocompatibility of CNTs and graphene by examining their cytotoxicity and/or detrimental effects on the human body for application to bioelectronics. Then, we scrutinize the various types of flexible and/or stretchable substrates that are integrated with CNTs and graphene for the construction of high-quality active electrode arrays and sensors. The convergence of these carbon-based materials and bioelectronics ensures scalability and cooperativity in various fields. Finally, future works with challenges are presented in bio-integrated electronic applications with these carbon-based materials.
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Affiliation(s)
- Taemin Kim
- School of Electrical Engineering, Yonsei University, Seoul 03722, Korea.
| | - Myeongki Cho
- School of Electrical Engineering, Yonsei University, Seoul 03722, Korea.
| | - Ki Jun Yu
- School of Electrical Engineering, Yonsei University, Seoul 03722, Korea.
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16
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Ngernsutivorakul T, White TS, Kennedy RT. Microfabricated Probes for Studying Brain Chemistry: A Review. Chemphyschem 2018; 19:1128-1142. [PMID: 29405568 PMCID: PMC6996029 DOI: 10.1002/cphc.201701180] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Indexed: 12/13/2022]
Abstract
Probe techniques for monitoring in vivo chemistry (e.g., electrochemical sensors and microdialysis sampling probes) have significantly contributed to a better understanding of neurotransmission in correlation to behaviors and neurological disorders. Microfabrication allows construction of neural probes with high reproducibility, scalability, design flexibility, and multiplexed features. This technology has translated well into fabricating miniaturized neurochemical probes for electrochemical detection and sampling. Microfabricated electrochemical probes provide a better control of spatial resolution with multisite detection on a single compact platform. This development allows the observation of heterogeneity of neurochemical activity precisely within the brain region. Microfabricated sampling probes are starting to emerge that enable chemical measurements at high spatial resolution and potential for reducing tissue damage. Recent advancement in analytical methods also facilitates neurochemical monitoring at high temporal resolution. Furthermore, a positive feature of microfabricated probes is that they can be feasibly built with other sensing and stimulating platforms including optogenetics. Such integrated probes will empower researchers to precisely elucidate brain function and develop novel treatments for neurological disorders.
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Affiliation(s)
| | - Thomas S. White
- Macromolecular Science and Engineering, University of Michigan, 3003E, NCRC Building 28, 2800 Plymouth Rd., Ann Arbor, MI 48109
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109
- Department of Pharmacology, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109
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17
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Young AT, Cornwell N, Daniele MA. Neuro-Nano Interfaces: Utilizing Nano-Coatings and Nanoparticles to Enable Next-Generation Electrophysiological Recording, Neural Stimulation, and Biochemical Modulation. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1700239. [PMID: 33867903 PMCID: PMC8049593 DOI: 10.1002/adfm.201700239] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Neural interfaces provide a window into the workings of the nervous system-enabling both biosignal recording and modulation. Traditionally, neural interfaces have been restricted to implanted electrodes to record or modulate electrical activity of the nervous system. Although these electrode systems are both mechanically and operationally robust, they have limited utility due to the resultant macroscale damage from invasive implantation. For this reason, novel nanomaterials are being investigated to enable new strategies to chronically interact with the nervous system at both the cellular and network level. In this feature article, the use of nanomaterials to improve current electrophysiological interfaces, as well as enable new nano-interfaces to modulate neural activity via alternative mechanisms, such as remote transduction of electromagnetic fields are explored. Specifically, this article will review the current use of nanoparticle coatings to enhance electrode function, then an analysis of the cutting-edge, targeted nanoparticle technologies being utilized to interface with both the electrophysiological and biochemical behavior of the nervous system will be provided. Furthermore, an emerging, specialized-use case for neural interfaces will be presented: the modulation of the blood-brain barrier.
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Affiliation(s)
- Ashlyn T Young
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Neil Cornwell
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
| | - Michael A Daniele
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, and North Carolina State University, 911 Oval Dr., Raleigh, NC 27695, USA
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18
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Hou J, Xie Y, Ji A, Cao A, Fang Y, Shi E. Carbon-Nanotube-Wrapped Spider Silks for Directed Cardiomyocyte Growth and Electrophysiological Detection. ACS APPLIED MATERIALS & INTERFACES 2018; 10:6793-6798. [PMID: 29424225 DOI: 10.1021/acsami.7b14793] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The combination of nanostructures with biomaterials offers great opportunities in constructing innovative functional devices such as biosensors and actuators. Here, we create a multifunctional fiber by wrapping a thin film of carbon nanotubes (CNTs) on naturally found spider silks, which shows great flexibility and conductivity. The hybrid CNT-silk fiber demonstrates intimate contact with cardiomyocytes and can direct the cell growth and simultaneously record potential signals evoked from cell beating. Cell activities reflected in the form of potential signals have been monitored clearly and reliably through the CNT-silk fibers without degradation over the long term.
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Affiliation(s)
- Junfeng Hou
- Marine College, Shandong University , Weihai 264209, P. R. China
- National Center for Nanoscience and Technology , 11 Beiyitiao Street, Zhongguancun, Beijing 100190, P. R. China
| | - Yu Xie
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, P. R. China
| | - Aiguo Ji
- Marine College, Shandong University , Weihai 264209, P. R. China
| | - Anyuan Cao
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, P. R. China
| | - Ying Fang
- National Center for Nanoscience and Technology , 11 Beiyitiao Street, Zhongguancun, Beijing 100190, P. R. China
| | - Enzheng Shi
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, P. R. China
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19
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Fiáth R, Raducanu BC, Musa S, Andrei A, Lopez CM, van Hoof C, Ruther P, Aarts A, Horváth D, Ulbert I. A silicon-based neural probe with densely-packed low-impedance titanium nitride microelectrodes for ultrahigh-resolution in vivo recordings. Biosens Bioelectron 2018; 106:86-92. [PMID: 29414094 DOI: 10.1016/j.bios.2018.01.060] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 01/10/2018] [Accepted: 01/26/2018] [Indexed: 12/26/2022]
Abstract
In this study, we developed and validated a single-shank silicon-based neural probe with 128 closely-packed microelectrodes suitable for high-resolution extracellular recordings. The 8-mm-long, 100-µm-wide and 50-µm-thick implantable shank of the probe fabricated using a 0.13-µm complementary metal-oxide-semiconductor (CMOS) metallization technology contains square-shaped (20 × 20 µm2), low-impedance (~ 50 kΩ at 1 kHz) recording sites made of rough and porous titanium nitride which are arranged in a 32 × 4 dense array with an inter-electrode pitch of 22.5 µm. The electrophysiological performance of the probe was tested in in vivo experiments by implanting it acutely into neocortical areas of anesthetized animals (rats, mice and cats). We recorded local field potentials, single- and multi-unit activity with superior quality from all layers of the neocortex of the three animal models, even after reusing the probe in multiple (> 10) experiments. The low-impedance electrodes monitored spiking activity with high signal-to-noise ratio; the peak-to-peak amplitude of extracellularly recorded action potentials of well-separable neurons ranged from 0.1 mV up to 1.1 mV. The high spatial sampling of neuronal activity made it possible to detect action potentials of the same neuron on multiple, adjacent recording sites, allowing a more reliable single unit isolation and the investigation of the spatiotemporal dynamics of extracellular action potential waveforms in greater detail. Moreover, the probe was developed with the specific goal to use it as a tool for the validation of electrophysiological data recorded with high-channel-count, high-density neural probes comprising integrated CMOS circuitry.
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Affiliation(s)
- Richárd Fiáth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter utca 50/A, H-1083 Budapest, Hungary.
| | - Bogdan Cristian Raducanu
- Interuniversity Microelectronics Center (IMEC), Kapeldreef 75, B-3001 Heverlee, Belgium; Electrical Engineering Department (ESAT), KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Silke Musa
- Interuniversity Microelectronics Center (IMEC), Kapeldreef 75, B-3001 Heverlee, Belgium
| | - Alexandru Andrei
- Interuniversity Microelectronics Center (IMEC), Kapeldreef 75, B-3001 Heverlee, Belgium
| | - Carolina Mora Lopez
- Interuniversity Microelectronics Center (IMEC), Kapeldreef 75, B-3001 Heverlee, Belgium
| | - Chris van Hoof
- Interuniversity Microelectronics Center (IMEC), Kapeldreef 75, B-3001 Heverlee, Belgium; Electrical Engineering Department (ESAT), KU Leuven, Kasteelpark Arenberg 10, B-3001 Leuven, Belgium
| | - Patrick Ruther
- Microsystem Materials Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence at the University of Freiburg, Georges-Koehler-Allee 80, D-79110 Freiburg, Germany
| | - Arno Aarts
- ATLAS Neuroengineering, Kapeldreef 75, B-3000 Leuven, Belgium
| | - Domonkos Horváth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter utca 50/A, H-1083 Budapest, Hungary
| | - István Ulbert
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar tudósok körútja 2, H-1117 Budapest, Hungary; Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter utca 50/A, H-1083 Budapest, Hungary
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20
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Prospects for a Robust Cortical Recording Interface. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00028-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Caldwell R, Sharma R, Takmakov P, Street MG, Solzbacher F, Tathireddy P, Rieth L. Neural electrode resilience against dielectric damage may be improved by use of highly doped silicon as a conductive material. J Neurosci Methods 2018; 293:210-225. [DOI: 10.1016/j.jneumeth.2017.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/01/2017] [Accepted: 10/02/2017] [Indexed: 11/28/2022]
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22
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Nelson MJ, Valtcheva S, Venance L. Magnitude and behavior of cross-talk effects in multichannel electrophysiology experiments. J Neurophysiol 2017; 118:574-594. [PMID: 28424297 DOI: 10.1152/jn.00877.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 04/17/2017] [Accepted: 04/18/2017] [Indexed: 12/29/2022] Open
Abstract
Modern neurophysiological experiments frequently involve multiple channels separated by very small distances. A unique methodological concern for multiple-electrode experiments is that of capacitive coupling (cross-talk) between channels. Yet the nature of the cross-talk recording circuit is not well known in the field, and the extent to which it practically affects neurophysiology experiments has never been fully investigated. Here we describe a simple electrical circuit model of simultaneous recording and stimulation with two or more channels and experimentally verify the model using ex vivo brain slice and in vivo whole-brain preparations. In agreement with the model, we find that cross-talk amplitudes increase nearly linearly with the impedance of a recording electrode and are larger for higher frequencies. We demonstrate cross-talk contamination of action potential waveforms from intracellular to extracellular channels, which is observable in part because of the different orders of magnitude between the channels. This contamination is electrode impedance-dependent and matches predictions from the model. We use recently published parameters to simulate cross-talk in high-density multichannel extracellular recordings. Cross-talk effectively spatially smooths current source density (CSD) estimates in these recordings and induces artefactual phase shifts where underlying voltage gradients occur; however, these effects are modest. We show that the effects of cross-talk are unlikely to affect most conclusions inferred from neurophysiology experiments when both originating and receiving electrode record signals of similar magnitudes. We discuss other types of experiments and analyses that may be susceptible to cross-talk, techniques for detecting and experimentally reducing cross-talk, and implications for high-density probe design.NEW & NOTEWORTHY We develop and experimentally verify an electrical circuit model describing cross-talk that necessarily occurs between two channels. Recorded cross-talk increased with electrode impedance and signal frequency. We recorded cross-talk contamination of spike waveforms from intracellular to extracellular channels. We simulated high-density multichannel extracellular recordings and demonstrate spatial smoothing and phase shifts that cross-talk enacts on CSD measurements. However, when channels record similar-magnitude signals, effects are modest and unlikely to affect most conclusions.
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Affiliation(s)
- Matthew J Nelson
- NeuroSpin Center, Cognitive Neuroimaging Unit, INSERM U992, Commissariat à l'Energie Atomique (CEA), Gif-sur-Yvette, France; and
| | - Silvana Valtcheva
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology, College de France, CNRS UMR7241/INSERM U1050, MemoLife Labex, Paris, France
| | - Laurent Venance
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology, College de France, CNRS UMR7241/INSERM U1050, MemoLife Labex, Paris, France
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23
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Harris AR, Paolini AG. Correlation of Impedance and Effective Electrode Area of Iridium Oxide Neural Electrodes. Aust J Chem 2017. [DOI: 10.1071/ch17218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Iridium oxide is routinely used for bionic applications owing to its high charge injection capacity. The electrode impedance at 1 kHz is typically reported to predict neural recording performance. In this article, the impedance of activated iridium oxide films (AIROFs) has been examined. The impedance of unactivated iridium electrodes was half that of platinum electrodes of similar geometry, indicating some iridium oxide was present on the electrode surface. A two time constant equivalent circuit was used to model the impedance of activated iridium. The impedance at low and intermediate frequencies decreased with increasing number of activation pulses and total activation charge. The impedance at 12 Hz correlated with the steady-state diffusion electroactive area. The impedance at 12 Hz also correlated with the charge density of the electrode. The high charge density and low impedance of AIROFs may provide improved neural stimulation and recording properties compared with typically used platinum electrodes.
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24
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Fan W, Li W, Zhang Y, Wang W, Zhang X, Song L, Liu X. Cooperative self-healing performance of shape memory polyurethane and Alodine-containing microcapsules. RSC Adv 2017. [DOI: 10.1039/c7ra09017j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this study, a method to prepare self-healing coatings by incorporating Alodine-containing microcapsules as fillers in Shape Memory Polyurethane (SMPU) was presented.
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Affiliation(s)
- Weijie Fan
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
- University of Chinese Academy of Sciences
| | - Weihua Li
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
| | - Yong Zhang
- Qingdao Branch of Naval Aeronautical University
- Qingdao 266041
- P. R. China
| | - Wei Wang
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
| | - Xiaoying Zhang
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
| | - Liying Song
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
| | - Xiaojie Liu
- Institute of Oceanology
- Chinese Academy of Sciences
- Qingdao 266071
- P. R. China
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25
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Zhao Z, Gong R, Zheng L, Wang J. In Vivo Neural Recording and Electrochemical Performance of Microelectrode Arrays Modified by Rough-Surfaced AuPt Alloy Nanoparticles with Nanoporosity. SENSORS (BASEL, SWITZERLAND) 2016; 16:E1851. [PMID: 27827893 PMCID: PMC5134510 DOI: 10.3390/s16111851] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 10/18/2016] [Accepted: 10/28/2016] [Indexed: 11/16/2022]
Abstract
In order to reduce the impedance and improve in vivo neural recording performance of our developed Michigan type silicon electrodes, rough-surfaced AuPt alloy nanoparticles with nanoporosity were deposited on gold microelectrode sites through electro-co-deposition of Au-Pt-Cu alloy nanoparticles, followed by chemical dealloying Cu. The AuPt alloy nanoparticles modified gold microelectrode sites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and in vivo neural recording experiment. The SEM images showed that the prepared AuPt alloy nanoparticles exhibited cauliflower-like shapes and possessed very rough surfaces with many different sizes of pores. Average impedance of rough-surfaced AuPt alloy nanoparticles modified sites was 0.23 MΩ at 1 kHz, which was only 4.7% of that of bare gold microelectrode sites (4.9 MΩ), and corresponding in vitro background noise in the range of 1 Hz to 7500 Hz decreased to 7.5 μ V rms from 34.1 μ V rms at bare gold microelectrode sites. Spontaneous spike signal recording was used to evaluate in vivo neural recording performance of modified microelectrode sites, and results showed that rough-surfaced AuPt alloy nanoparticles modified microelectrode sites exhibited higher average spike signal-to-noise ratio (SNR) of 4.8 in lateral globus pallidus (GPe) due to lower background noise compared to control microelectrodes. Electro-co-deposition of Au-Pt-Cu alloy nanoparticles combined with chemical dealloying Cu was a convenient way for increasing the effective surface area of microelectrode sites, which could reduce electrode impedance and improve the quality of in vivo spike signal recording.
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Affiliation(s)
- Zongya Zhao
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
- National Engineering Research Center of Health Care and Medical Devices, Xi'an Jiaotong University Branch, Xi'an 710049, China.
| | - Ruxue Gong
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
- National Engineering Research Center of Health Care and Medical Devices, Xi'an Jiaotong University Branch, Xi'an 710049, China.
| | - Liang Zheng
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
- National Engineering Research Center of Health Care and Medical Devices, Xi'an Jiaotong University Branch, Xi'an 710049, China.
| | - Jue Wang
- Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
- National Engineering Research Center of Health Care and Medical Devices, Xi'an Jiaotong University Branch, Xi'an 710049, China.
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26
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Vallejo-Giraldo C, Pugliese E, Larrañaga A, Fernandez-Yague MA, Britton JJ, Trotier A, Tadayyon G, Kelly A, Rago I, Sarasua JR, Dowd E, Quinlan LR, Pandit A, Biggs MJP. Polyhydroxyalkanoate/carbon nanotube nanocomposites: flexible electrically conducting elastomers for neural applications. Nanomedicine (Lond) 2016; 11:2547-63. [DOI: 10.2217/nnm-2016-0075] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Aim: Medium chain length-polyhydroxyalkanoate/multi-walled carbon nanotube (MWCNTs) nanocomposites with a range of mechanical and electrochemical properties were fabricated via assisted dispersion and solvent casting, and their suitability as neural interface biomaterials was investigated. Materials & methods: Mechanical and electrical properties of medium chain length-polyhydroxyalkanoate/MWCNTs nanocomposite films were evaluated by tensile test and electrical impedance spectroscopy, respectively. Primary rat mesencephalic cells were seeded on the composites and quantitative immunostaining of relevant neural biomarkers, and electrical stimulation studies were performed. Results: Incorporation of MWCNTs to the polymeric matrix modulated the mechanical and electrical properties of resulting composites, and promoted differential cell viability, morphology and function as a function of MWCNT concentration. Conclusion: This study demonstrates the feasibility of a green thermoplastic MWCNTs nanocomposite for potential use in neural interfacing applications.
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Affiliation(s)
- Catalina Vallejo-Giraldo
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - Eugenia Pugliese
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - Aitor Larrañaga
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Mining-Metallurgy Engineering & Materials Science & POLYMAT, School of Engineering, University of the Basque Country (UPV/EHU) 480130 Bilbao, Spain
| | - Marc A Fernandez-Yague
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - James J Britton
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - Alexandre Trotier
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Ghazal Tadayyon
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
| | - Adriona Kelly
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - Ilaria Rago
- Department of Physics, University of Trieste, Via Valerio 2-34127, Trieste, Italy
| | - Jose-Ramon Sarasua
- Department of Mining-Metallurgy Engineering & Materials Science & POLYMAT, School of Engineering, University of the Basque Country (UPV/EHU) 480130 Bilbao, Spain
| | - Eilís Dowd
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Physics, University of Trieste, Via Valerio 2-34127, Trieste, Italy
| | - Leo R Quinlan
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Pharmacology, National University of Ireland, Galway, Ireland
| | - Abhay Pandit
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
| | - Manus JP Biggs
- CÚRAM – Centre for Research in Medical Devices, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, National University of Ireland, Galway, Ireland
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Burblies N, Schulze J, Schwarz HC, Kranz K, Motz D, Vogt C, Lenarz T, Warnecke A, Behrens P. Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells. PLoS One 2016; 11:e0158571. [PMID: 27385031 PMCID: PMC4934701 DOI: 10.1371/journal.pone.0158571] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 06/18/2016] [Indexed: 12/28/2022] Open
Abstract
Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes.
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Affiliation(s)
- Niklas Burblies
- Institute for Inorganic Chemistry, Leibniz University Hannover, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Jennifer Schulze
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Hans-Christoph Schwarz
- Institute for Inorganic Chemistry, Leibniz University Hannover, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Katharina Kranz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Damian Motz
- Institute for Inorganic Chemistry, Leibniz University Hannover, Hanover, Germany
| | - Carla Vogt
- Institute for Inorganic Chemistry, Leibniz University Hannover, Hanover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Athanasia Warnecke
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
| | - Peter Behrens
- Institute for Inorganic Chemistry, Leibniz University Hannover, Hanover, Germany
- Cluster of Excellence Hearing4all, Hanover, Germany
- * E-mail:
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28
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Simon DT, Gabrielsson EO, Tybrandt K, Berggren M. Organic Bioelectronics: Bridging the Signaling Gap between Biology and Technology. Chem Rev 2016; 116:13009-13041. [PMID: 27367172 DOI: 10.1021/acs.chemrev.6b00146] [Citation(s) in RCA: 217] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electronics surrounding us in our daily lives rely almost exclusively on electrons as the dominant charge carrier. In stark contrast, biological systems rarely use electrons but rather use ions and molecules of varying size. Due to the unique combination of both electronic and ionic/molecular conductivity in conducting and semiconducting organic polymers and small molecules, these materials have emerged in recent decades as excellent tools for translating signals between these two realms and, therefore, providing a means to effectively interface biology with conventional electronics-thus, the field of organic bioelectronics. Today, organic bioelectronics defines a generic platform with unprecedented biological recording and regulation tools and is maturing toward applications ranging from life sciences to the clinic. In this Review, we introduce the field, from its early breakthroughs to its current results and future challenges.
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Affiliation(s)
- Daniel T Simon
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University , 60174 Norrköping, Sweden
| | - Erik O Gabrielsson
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University , 60174 Norrköping, Sweden
| | - Klas Tybrandt
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University , 60174 Norrköping, Sweden.,Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich , 8092 Zürich, Switzerland
| | - Magnus Berggren
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University , 60174 Norrköping, Sweden
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29
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Li C, Narayan RK, Wu PM, Rajan N, Wu Z, Mehan N, Golanov EV, Ahn CH, Hartings JA. Evaluation of microelectrode materials for direct-current electrocorticography. J Neural Eng 2015; 13:016008. [DOI: 10.1088/1741-2560/13/1/016008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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30
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Chung T, Wang JQ, Wang J, Cao B, Li Y, Pang SW. Electrode modifications to lower electrode impedance and improve neural signal recording sensitivity. J Neural Eng 2015; 12:056018. [DOI: 10.1088/1741-2560/12/5/056018] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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31
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Duffy BA, Choy M, Chuapoco MR, Madsen M, Lee JH. MRI compatible optrodes for simultaneous LFP and optogenetic fMRI investigation of seizure-like afterdischarges. Neuroimage 2015. [PMID: 26208873 DOI: 10.1016/j.neuroimage.2015.07.038] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In preclinical studies, implanted electrodes can cause severe degradation of MRI images and hence are seldom used for chronic studies employing functional magnetic resonance imaging. In this study, we developed carbon fiber optrodes (optical fiber and electrode hybrid devices), which can be utilised in chronic longitudinal studies aiming to take advantage of emerging optogenetic technologies, and compared them with the more widely used tungsten optrodes. We find that optrodes constructed using small diameter (~130 μm) carbon fiber electrodes cause significantly reduced artifact on functional MRI images compared to those made with 50 μm diameter tungsten wire and at the same time the carbon electrodes have lower impedance, which leads to higher quality LFP recordings. In order to validate this approach, we use these devices to study optogenetically-induced seizure-like afterdischarges in rats sedated with dexmedetomidine and compare these to sub (seizure) threshold stimulations in the same animals. The results indicate that seizure-like afterdischarges involve several extrahippocampal brain regions that are not recruited by subthreshold optogenetic stimulation of the hippocampus at 20 Hz. Subthreshold stimulation led to activation of the entire ipsilateral hippocampus and septum, whereas afterdischarges additionally produced activations in the contralateral hippocampal formation, neocortex, cerebellum, nucleus accumbens, and thalamus. Although we demonstrate just one application, given the ease of fabrication, we anticipate that carbon fiber optrodes could be utilised in a variety of studies that could benefit from longitudinal optogenetic functional magnetic resonance imaging.
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Affiliation(s)
- Ben A Duffy
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305 Stanford, CA, USA
| | - ManKin Choy
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305 Stanford, CA, USA
| | - Miguel R Chuapoco
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305 Stanford, CA, USA
| | - Michael Madsen
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305 Stanford, CA, USA
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305 Stanford, CA, USA; Department of Bioengineering, Stanford University, CA 94305 Stanford, CA, USA; Department of Neurosurgery, Stanford University, CA 94305 Stanford, CA, USA; Department of Electrical Engineering, Stanford University, CA 94305 Stanford, CA, USA.
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32
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Samba R, Herrmann T, Zeck G. PEDOT–CNT coated electrodes stimulate retinal neurons at low voltage amplitudes and low charge densities. J Neural Eng 2015; 12:016014. [DOI: 10.1088/1741-2560/12/1/016014] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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33
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Harris AR, Molino PJ, Kapsa RMI, Clark GM, Paolini AG, Wallace GG. Correlation of the impedance and effective electrode area of doped PEDOT modified electrodes for brain–machine interfaces. Analyst 2015; 140:3164-74. [DOI: 10.1039/c4an02362e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
An analytical solution to impedance allows correlation of an effective electrode area with the impedance and phase angle at low frequencies.
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Affiliation(s)
| | - Paul J. Molino
- Intelligent Polymer Research Institute
- University of Wollongong
- Wollongong
- Australia
| | - Robert M. I. Kapsa
- Intelligent Polymer Research Institute
- University of Wollongong
- Wollongong
- Australia
- Department of Neurosciences
| | - Graeme M. Clark
- School of Engineering
- University of Melbourne
- Parkville
- Australia
| | - Antonio G. Paolini
- Health Innovations Research Institute
- College of Science
- Engineering and Health
- RMIT University
- Bundoora
| | - Gordon G. Wallace
- Intelligent Polymer Research Institute
- University of Wollongong
- Wollongong
- Australia
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34
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Jorfi M, Skousen JL, Weder C, Capadona JR. Progress towards biocompatible intracortical microelectrodes for neural interfacing applications. J Neural Eng 2014; 12:011001. [PMID: 25460808 DOI: 10.1088/1741-2560/12/1/011001] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To ensure long-term consistent neural recordings, next-generation intracortical microelectrodes are being developed with an increased emphasis on reducing the neuro-inflammatory response. The increased emphasis stems from the improved understanding of the multifaceted role that inflammation may play in disrupting both biologic and abiologic components of the overall neural interface circuit. To combat neuro-inflammation and improve recording quality, the field is actively progressing from traditional inorganic materials towards approaches that either minimizes the microelectrode footprint or that incorporate compliant materials, bioactive molecules, conducting polymers or nanomaterials. However, the immune-privileged cortical tissue introduces an added complexity compared to other biomedical applications that remains to be fully understood. This review provides a comprehensive reflection on the current understanding of the key failure modes that may impact intracortical microelectrode performance. In addition, a detailed overview of the current status of various materials-based approaches that have gained interest for neural interfacing applications is presented, and key challenges that remain to be overcome are discussed. Finally, we present our vision on the future directions of materials-based treatments to improve intracortical microelectrodes for neural interfacing.
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Affiliation(s)
- Mehdi Jorfi
- Adolphe Merkle Institute, University of Fribourg, Rte de l'Ancienne Papeterie, CH-1723 Marly, Switzerland
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35
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Homer ML, Perge JA, Black MJ, Harrison MT, Cash SS, Hochberg LR. Adaptive offset correction for intracortical brain-computer interfaces. IEEE Trans Neural Syst Rehabil Eng 2014; 22:239-48. [PMID: 24196868 DOI: 10.1109/tnsre.2013.2287768] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Intracortical brain-computer interfaces (iBCIs) decode intended movement from neural activity for the control of external devices such as a robotic arm. Standard approaches include a calibration phase to estimate decoding parameters. During iBCI operation, the statistical properties of the neural activity can depart from those observed during calibration, sometimes hindering a user's ability to control the iBCI. To address this problem, we adaptively correct the offset terms within a Kalman filter decoder via penalized maximum likelihood estimation. The approach can handle rapid shifts in neural signal behavior (on the order of seconds) and requires no knowledge of the intended movement. The algorithm, called multiple offset correction algorithm (MOCA), was tested using simulated neural activity and evaluated retrospectively using data collected from two people with tetraplegia operating an iBCI. In 19 clinical research test cases, where a nonadaptive Kalman filter yielded relatively high decoding errors, MOCA significantly reduced these errors ( 10.6 ± 10.1% ; p < 0.05, pairwise t-test). MOCA did not significantly change the error in the remaining 23 cases where a nonadaptive Kalman filter already performed well. These results suggest that MOCA provides more robust decoding than the standard Kalman filter for iBCIs.
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36
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37
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Kuzum D, Takano H, Shim E, Reed JC, Juul H, Richardson AG, de Vries J, Bink H, Dichter MA, Lucas TH, Coulter DA, Cubukcu E, Litt B. Transparent and flexible low noise graphene electrodes for simultaneous electrophysiology and neuroimaging. Nat Commun 2014; 5:5259. [PMID: 25327632 DOI: 10.1038/ncomms6259] [Citation(s) in RCA: 264] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 09/12/2014] [Indexed: 12/24/2022] Open
Abstract
Calcium imaging is a versatile experimental approach capable of resolving single neurons with single-cell spatial resolution in the brain. Electrophysiological recordings provide high temporal, but limited spatial resolution, because of the geometrical inaccessibility of the brain. An approach that integrates the advantages of both techniques could provide new insights into functions of neural circuits. Here, we report a transparent, flexible neural electrode technology based on graphene, which enables simultaneous optical imaging and electrophysiological recording. We demonstrate that hippocampal slices can be imaged through transparent graphene electrodes by both confocal and two-photon microscopy without causing any light-induced artefacts in the electrical recordings. Graphene electrodes record high-frequency bursting activity and slow synaptic potentials that are hard to resolve by multicellular calcium imaging. This transparent electrode technology may pave the way for high spatio-temporal resolution electro-optic mapping of the dynamic neuronal activity.
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Affiliation(s)
- Duygu Kuzum
- 1] Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Hajime Takano
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA [3] Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [4] Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Euijae Shim
- 1] Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jason C Reed
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Halvor Juul
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Andrew G Richardson
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Julius de Vries
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Hank Bink
- 1] Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Marc A Dichter
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Timothy H Lucas
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Douglas A Coulter
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA [3] Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [4] Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Ertugrul Cubukcu
- 1] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [3] Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Brian Litt
- 1] Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [2] Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA [3] Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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38
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Castagnola V, Descamps E, Lecestre A, Dahan L, Remaud J, Nowak LG, Bergaud C. Parylene-based flexible neural probes with PEDOT coated surface for brain stimulation and recording. Biosens Bioelectron 2014; 67:450-7. [PMID: 25256782 DOI: 10.1016/j.bios.2014.09.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/14/2014] [Accepted: 09/02/2014] [Indexed: 12/01/2022]
Abstract
Implantable neural prosthetics devices offer a promising opportunity for the restoration of lost functions in patients affected by brain or spinal cord injury, by providing the brain with a non-muscular channel able to link machines to the nervous system. Nevertheless current neural microelectrodes suffer from high initial impedance and low charge-transfer capacity because of their small-feature geometry (Abidian et al., 2010; Cui and Zhou, 2007). In this work we have developed PEDOT-modified neural probes based on flexible substrate capable to answer to the three critical requirements for neuroprosthetic device: efficiency, lifetime and biocompatibility. We propose a simple procedure for the fabrication of neural electrodes fully made of Parylene-C, followed by an electropolymerization of the active area with the conductive polymer PEDOT that is shown to greatly enhance the electrical performances of the device. In addition, the biocompatibility and the very high SNR exhibited during signal recording make our device suitable for long-term implantation.
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Affiliation(s)
- V Castagnola
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; University of Toulouse, LAAS, F-31400 Toulouse, France.
| | - E Descamps
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; University of Toulouse, LAAS, F-31400 Toulouse, France.
| | - A Lecestre
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; University of Toulouse, LAAS, F-31400 Toulouse, France.
| | - L Dahan
- Centre de Recherche sur la Cognition Animale (CRCA), University of Toulouse, France.
| | - J Remaud
- Centre de Recherche sur la Cognition Animale (CRCA), University of Toulouse, France.
| | - L G Nowak
- Centre de Recherche Cerveau et Cognition (CerCo), CNRS, Toulouse, France.
| | - C Bergaud
- CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; University of Toulouse, LAAS, F-31400 Toulouse, France.
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39
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Liu Z, Yu M, Lv J, Li Y, Yu Z. Dispersed, porous nanoislands landing on stretchable nanocrack gold films: maintenance of stretchability and controllable impedance. ACS APPLIED MATERIALS & INTERFACES 2014; 6:13487-13495. [PMID: 25090109 DOI: 10.1021/am502454t] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Stretchable electronic devices have great potential for serving as bioelectrical interfaces due to their better deformability and modulus match with biological organs. However, surface modification, which is usually applied to enhance the capability of sensing and stimulating, as well as biocompatibility, may cause problems since their stretchability highly depends on the surface structure. In this work, stretchable nanocrack gold (SNCG) electrodes were fabricated, which can be stretched by a maximum 120% uniaxial strain while maintaining their electrical conductivity. We found that the electrodes lost their stretchability after surface modification of an additional continuous platinum layer, which was found to selectively weld or fully cover the nanocracks, consequently eliminating its crack structure. To address this issue, we designed a complex structure of dispersed, porous nanoislands landing on the SNCG film, which was further demonstrated as capable of maintaining the stretchability of electrodes while allowing the reshaping of cracks. Moreover, stretchable microelectrode arrays were then developed with this complex structure. Animal experiments demonstrated their capability of conformally wrapping on a rat brain cortex and effectively monitoring an intracranial electroencephalogram under deformation. In addition, their impedance can be precisely controlled by modulating the dispersity, diameter, and aspect ratio of individual nanoislands. This complex structure has great potential for developing highly stretchable, multiplexing sensors, allowing stiff materials to land on a stretchable conducting surface with maintenance of stretchability and controllable functional area.
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Affiliation(s)
- Zhiyuan Liu
- Biomedical Microdevices Research Laboratory, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , 1068 Xueyuan Avenue, Shenzhen 518055, China
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Angotzi GN, Boi F, Zordan S, Bonfanti A, Vato A. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals. Sci Rep 2014; 4:5963. [PMID: 25096831 PMCID: PMC4123143 DOI: 10.1038/srep05963] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/10/2014] [Indexed: 11/08/2022] Open
Abstract
A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays.
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Affiliation(s)
- Gian Nicola Angotzi
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova, Italy
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genova, Italy
| | - Fabio Boi
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genova, Italy
| | - Stefano Zordan
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genova, Italy
| | - Andrea Bonfanti
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy
| | - Alessandro Vato
- Center for Neuroscience and Cognitive Systems @UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genova, Italy
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Xu J, Wu T, Liu W, Yang Z. A frequency shaping neural recorder with 3 pF input capacitance and 11 plus 4.5 bits dynamic range. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2014; 8:510-527. [PMID: 25073127 DOI: 10.1109/tbcas.2013.2293821] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper presents a frequency-shaping (FS) neural recording architecture and its implementation in a 0.13 μ m CMOS process. Compared with its conventional counterpart, the proposed architecture inherently rejects electrode offset, increases input impedance 5-10 fold, compresses neural data dynamic range (DR) by 4.5-bit, simultaneously records local field potentials (LFPs) and extracellular spikes, and is more suitable for long-term recording experiments. Measured at a 40 kHz sampling clock and ± 0.6 V supply, the recorder consumes 50 μW/ch, of which 22 μW per FS amplifier, 24 μ W per buffer, 4 μ W per 11-bit successive approximation register analog-to-digital converter (SAR ADC). The input-referred noise for LFPs and extracellular spikes are 13 μ Vrms and 7 μVrms, respectively, which are sufficient to achieve high-fidelity full-spectrum neural data. In addition, the designed recorder has a 3 pF input capacitance and allows " 11+4.5"-bit neural data DR without system saturation, where the extra 4.5-bit owes to the FS technique. Its figure-of-merit (FOM) based on data DR reaches 36.0 fJ/conversion-step.
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A comparative study of nano-scale coatings on gold electrodes for bioimpedance studies of breast cancer cells. Biomed Microdevices 2014; 16:689-96. [DOI: 10.1007/s10544-014-9873-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Castagnola E, Ansaldo A, Maggiolini E, Ius T, Skrap M, Ricci D, Fadiga L. Smaller, softer, lower-impedance electrodes for human neuroprosthesis: a pragmatic approach. FRONTIERS IN NEUROENGINEERING 2014; 7:8. [PMID: 24795621 PMCID: PMC3997015 DOI: 10.3389/fneng.2014.00008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 03/29/2014] [Indexed: 12/19/2022]
Abstract
Finding the most appropriate technology for building electrodes to be used for long term implants in humans is a challenging issue. What are the most appropriate technologies? How could one achieve robustness, stability, compatibility, efficacy, and versatility, for both recording and stimulation? There are no easy answers to these questions as even the most fundamental and apparently obvious factors to be taken into account, such as the necessary mechanical, electrical and biological properties, and their interplay, are under debate. We present here our approach along three fundamental parallel pathways: we reduced electrode invasiveness and size without impairing signal-to-noise ratio, we increased electrode active surface area by depositing nanostructured materials, and we protected the brain from direct contact with the electrode without compromising performance. Altogether, these results converge toward high-resolution ECoG arrays that are soft and adaptable to cortical folds, and have been proven to provide high spatial and temporal resolution. This method provides a piece of work which, in our view, makes several steps ahead in bringing such novel devices into clinical settings, opening new avenues in diagnostics of brain diseases, and neuroprosthetic applications.
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Affiliation(s)
- Elisa Castagnola
- Robotics, Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy
| | - Alberto Ansaldo
- Robotics, Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy
| | - Emma Maggiolini
- Robotics, Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy
| | - Tamara Ius
- Struttura Complessa di Neurochirurgia, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia Udine, Italy
| | - Miran Skrap
- Struttura Complessa di Neurochirurgia, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia Udine, Italy
| | - Davide Ricci
- Robotics, Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy
| | - Luciano Fadiga
- Robotics, Brain and Cognitive Sciences Department, Istituto Italiano di Tecnologia Genoa, Italy ; Section of Human Physiology, Department of Biomedical Sciences, University of Ferrara Ferrara, Italy
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De Faveri S, Maggiolini E, Miele E, De Angelis F, Cesca F, Benfenati F, Fadiga L. Bio-inspired hybrid microelectrodes: a hybrid solution to improve long-term performance of chronic intracortical implants. FRONTIERS IN NEUROENGINEERING 2014; 7:7. [PMID: 24782757 PMCID: PMC3989589 DOI: 10.3389/fneng.2014.00007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/24/2014] [Indexed: 12/16/2022]
Abstract
The use of implants that allow chronic electrical stimulation and recording in the brain of human patients is currently limited by a series of events that cause the deterioration over time of both the electrode surface and the surrounding tissue. The main reason of failure is the tissue inflammatory reaction that eventually causes neuronal loss and glial encapsulation, resulting in a progressive increase of the electrode-electrolyte impedance. Here, we describe a new method to create bio-inspired electrodes to mimic the mechanical properties and biological composition of the host tissue. This combination has a great potential to increase the implant lifetime by reducing tissue reaction and improving electrical coupling. Our method implies coating the electrode with reprogrammed neural or glial cells encapsulated within a hydrogel layer. We chose fibrin as a hydrogel and primary hippocampal neurons or astrocytes from rat brain as cellular layer. We demonstrate that fibrin coating is highly biocompatible, forms uniform coatings of controllable thickness, does not alter the electrochemical properties of the microelectrode and allows good quality recordings. Moreover, it reduces the amount of host reactive astrocytes – over time – compared to a bare wire and is fully reabsorbed by the surrounding tissue within 7 days after implantation, avoiding the common problem of hydrogels swelling. Both astrocytes and neurons could be successfully grown onto the electrode surface within the fibrin hydrogel without altering the electrochemical properties of the microelectrode. This bio-hybrid device has therefore a good potential to improve the electrical integration at the neuron-electrode interface and support the long-term success of neural prostheses.
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Affiliation(s)
- Sara De Faveri
- Department of Robotics, Brain and Cognitive Science, Istituto Italiano di Tecnologia Genova, Italy ; Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Emma Maggiolini
- Department of Robotics, Brain and Cognitive Science, Istituto Italiano di Tecnologia Genova, Italy
| | - Ermanno Miele
- Department of Nanostructures, Istituto Italiano di Tecnologia Genova, Italy
| | | | - Fabrizia Cesca
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Fabio Benfenati
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy ; Department of Experimental Medicine, University of Genova Genova, Italy
| | - Luciano Fadiga
- Department of Robotics, Brain and Cognitive Science, Istituto Italiano di Tecnologia Genova, Italy ; Section of Human Physiology, University of Ferrara Ferrara, Italy
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Márton G, Bakos I, Fekete Z, Ulbert I, Pongrácz A. Durability of high surface area platinum deposits on microelectrode arrays for acute neural recordings. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:931-940. [PMID: 24318022 DOI: 10.1007/s10856-013-5114-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 11/29/2013] [Indexed: 06/02/2023]
Abstract
The durability of high surface area platinum electrodes during acute intracerebral measurements was investigated. Electrode sites with extremely rough surfaces were realized using electrochemical deposition of platinum onto silicon-based microelectrode arrays from a lead-free platinizing solution. The close to 1000-fold increase in effective surface area lowered impedance, its absolute value at 1 kHz became about 7 and 18 % of the original Pt electrodes in vitro and in vivo, respectively. 24-channel probes were subjected to 12 recording sessions, during which they were implanted into the cerebrum of rats. Our results showed that although on the average the effective surface area of the platinized sites decreased, it remained more than two orders of magnitude higher than the average effective surface area of the original, sputtered thin-film platinum electrodes. Sites with electrochemical deposits proved to be superior, e.g. they provided less thermal and 50 Hz noise, even after 12 penetrations into the intact rat brain.
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Affiliation(s)
- Gergely Márton
- Department of Comparative Psychophysiology, Institute of Cognitive Neuroscience and Psychology, RCNS, HAS, Victor Hugo u. 18-22, Budapest, 1132, Hungary,
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Charkhkar H, Knaack GL, Mandal HS, Keefer EW, Pancrazio JJ. Effects of carbon nanotube and conducting polymer coated microelectrodes on single-unit recordings in vitro. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2014; 2014:469-473. [PMID: 25569998 DOI: 10.1109/embc.2014.6943630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Neuronal networks cultured on microelectrode arrays (MEAs) have been utilized as biosensors that can detect all or nothing extracellular action potentials, or spikes. Coating the microelectrodes with carbon nanotubes (CNTs), either pristine or conjugated with a conductive polymer, has been previously reported to improve extracellular recordings presumably via reduction in microelectrode impedance. The goal of this work was to examine the basis of such improvement in vitro. Every other microelectrode of in vitro MEAs was electrochemically modified with either conducting polymer, poly-3,4-ethylenedioxythiophene (PEDOT) or a blend of CNT and PEDOT. Mouse cortical tissue was dissociated and cultured on the MEAs to form functional neuronal networks. The performance of the modified and unmodified microelectrodes was evaluated by activity measures such as spike rate, spike amplitude, burst duration and burst rate. We observed that the yield, defined as percentage of microelectrodes with neuronal activity, was significantly higher by 55% for modified microelectrodes compared to the unmodified sites. However, the spike rate and burst parameters were similar for modified and unmodified microelectrodes suggesting that neuronal networks were not physiologically altered by presence of PEDOT or PEDOT-CNT. Our observations from immunocytochemistry indicated that neuronal cells were more abundant in proximity to modified microelectrodes.
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Kim T, Branner A, Gulati T, Giszter SF. Braided multi-electrode probes: mechanical compliance characteristics and recordings from spinal cords. J Neural Eng 2013; 10:045001. [PMID: 23723128 DOI: 10.1088/1741-2560/10/4/045001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To test a novel braided multi-electrode probe design with compliance exceeding that of a 50 µm microwire, thus reducing micromotion- and macromotion-induced tissue stress. APPROACH We use up to 24 ultra-fine wires interwoven into a tubular braid to obtain a highly flexible multi-electrode probe. The tether-portion wires are simply non-braided extensions of the braid structure, allowing the microprobe to follow gross neural tissue movements. Mechanical calculation and direct measurements evaluated bending stiffness and axial compression forces in the probe and tether system. These were compared to 50 µm nichrome microwire standards. Recording tests were performed in decerebrate animals. MAIN RESULTS Mechanical bending tests on braids comprising 9.6 or 12.7 µm nichrome wires showed that implants (braided portions) had 4 to 21 times better mechanical compliance than a single 50 µm wire and non-braided tethers were 6 to 96 times better. Braided microprobes yielded robust neural recordings from animals' spinal cords throughout cord motions. SIGNIFICANCE Microwire electrode arrays that can record and withstand tissue micro- and macromotion of spinal cord tissues are demonstrated. This technology may provide a stable chronic neural interface into spinal cords of freely moving animals, is extensible to various applications, and may reduce mechanical tissue stress.
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Affiliation(s)
- Taegyo Kim
- School of Biomedical Engineering, Science and Health System, Drexel University, Philadelphia, PA, USA
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Zhou H, Cheng X, Rao L, Li T, Duan YY. Poly(3,4-ethylenedioxythiophene)/multiwall carbon nanotube composite coatings for improving the stability of microelectrodes in neural prostheses applications. Acta Biomater 2013; 9:6439-49. [PMID: 23402765 DOI: 10.1016/j.actbio.2013.01.042] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Revised: 01/26/2013] [Accepted: 01/31/2013] [Indexed: 02/02/2023]
Abstract
With the purpose of improving the stability of microelectrodes under continuous high charge density stimulation, which is required for neural prostheses applications such as visual prostheses, multiwall carbon nanotube (MWCNT)-doped poly(3,4-ethylenedioxythiophene) (PEDOT) composite films were coated onto a platinum microelectrode by electrochemical polymerization. Galvanostatically polymerized PEDOT/MWCNT films demonstrated superior characteristics compared to polystyrene sulfonate doping and potentiostatic polymerization, including a three-dimensional cone morphology and enhanced electrochemical performance (the safe charge injection limit reached 6.2 mC cm(-2) for cathodic-first pulses). Most important of all, the improved stability of the coatings has been revealed through stimulation for 96 h using 3.0 mCc m(-2) current pulses in bicarbonate- and phosphate-buffered saline solution. Cell assays revealed that PEDOT/MWCNT films could promote the adhesion and neurite outgrowth of rat pheochromocytoma cells. Finally, platinum wires coated with PEDOT/MWCNT films were implanted into rat cortex for 6 weeks for histological evaluation. Glial fibrillary acidic protein and neuronal nuclei staining revealed that the films elicit a lower tissue response compared to platinum implants. These results suggest that the galvanostatically polymerized PEDOT/MWCNT films can improve the stability of stimulation microelectrodes and that PEDOT/MWCNT is an excellent candidate material for electrode coating for neural prostheses applications.
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Bareket-Keren L, Hanein Y. Carbon nanotube-based multi electrode arrays for neuronal interfacing: progress and prospects. Front Neural Circuits 2013; 6:122. [PMID: 23316141 PMCID: PMC3540767 DOI: 10.3389/fncir.2012.00122] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/22/2012] [Indexed: 12/17/2022] Open
Abstract
Carbon nanotube (CNT) coatings have been demonstrated over the past several years as a promising material for neuronal interfacing applications. In particular, in the realm of neuronal implants, CNTs have major advantages owing to their unique mechanical and electrical properties. Here we review recent investigations utilizing CNTs in neuro-interfacing applications. Cell adhesion, neuronal engineering and multi electrode recordings with CNTs are described. We also highlight prospective advances in this field, in particular, progress toward flexible, bio-compatible CNT-based technology.
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Affiliation(s)
- Lilach Bareket-Keren
- School of Electrical Engineering, Tel-Aviv UniversityTel-Aviv, Israel
- Tel-Aviv University Center for Nanoscience and Nanotechnology, Tel-Aviv UniversityTel-Aviv, Israel
| | - Yael Hanein
- School of Electrical Engineering, Tel-Aviv UniversityTel-Aviv, Israel
- Tel-Aviv University Center for Nanoscience and Nanotechnology, Tel-Aviv UniversityTel-Aviv, Israel
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Harris AR, Morgan SJ, Chen J, Kapsa RMI, Wallace GG, Paolini AG. Conducting polymer coated neural recording electrodes. J Neural Eng 2012; 10:016004. [DOI: 10.1088/1741-2560/10/1/016004] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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