1
|
Wang Q, Liu Y, Zhang B, Dong J, Wang L. Advancing the Frontiers of Neuroelectrodes: A Paradigm Shift towards Enhanced Biocompatibility and Electrochemical Performance. Polymers (Basel) 2024; 16:1457. [PMID: 38891404 PMCID: PMC11174417 DOI: 10.3390/polym16111457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
The aim of this study is the fabrication of unprecedented neuroelectrodes, replete with exceptional biological and electrical attributes. Commencing with the synthesis of polyethylene glycol and polyethyleneimine-modified iron oxide nanoparticles, the grafting of Dimyristoyl phosphatidylcholine was embarked upon to generate DMPC-SPION nanoparticles. Subsequently, the deposition of DMPC-SPIONs onto a nickel-chromium alloy electrode facilitated the inception of an innovative neuroelectrode-DMPC-SPION. A meticulous characterization of DMPC-SPIONs ensued, encompassing zeta potential, infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analyses. Evaluations pertaining to hemolysis and cytotoxicity were conducted to ascertain the biocompatibility and biosafety of DMPC-SPIONs. Ultimately, a comprehensive assessment of the biocompatibility, electrochemical properties, and electrophysiological signal acquisition capabilities of DMPC-SPION neuroelectrodes was undertaken. These findings conclusively affirm the exemplary biocompatibility, electrochemical capabilities, and outstanding capability in recording electrical signals of DMPC-SPION neuroelectrodes, with an astounding 91.4% augmentation in electrode charge and a noteworthy 13% decline in impedance, with peak potentials reaching as high as 171 μV and an impressive signal-to-noise ratio of 15.92. Intriguingly, the novel DMPC-SPION neuroelectrodes herald an innovative pathway towards injury repair as well as the diagnosis and treatment of neurological disorders.
Collapse
Affiliation(s)
- Qin Wang
- School of Intelligent Medicine and Biotechnology, Guangxi Engineering Research Center of Digital Medicine and Clinical Translation, Guilin Medical University, Guilin 541004, China;
| | - Yiyang Liu
- Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China; (Y.L.); (B.Z.)
| | - Baolin Zhang
- Guangxi Key Laboratory of Optical and Electronic Materials and Devices, College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China; (Y.L.); (B.Z.)
| | - Jianghui Dong
- School of Intelligent Medicine and Biotechnology, Guangxi Engineering Research Center of Digital Medicine and Clinical Translation, Guilin Medical University, Guilin 541004, China;
| | - Liping Wang
- School of Intelligent Medicine and Biotechnology, Guangxi Engineering Research Center of Digital Medicine and Clinical Translation, Guilin Medical University, Guilin 541004, China;
| |
Collapse
|
2
|
Han J, Choi J, Jeong H, Park D, Cheong E, Sung J, Choi HJ. Impact of Impedance Levels on Recording Quality in Flexible Neural Probes. SENSORS (BASEL, SWITZERLAND) 2024; 24:2300. [PMID: 38610511 PMCID: PMC11014004 DOI: 10.3390/s24072300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/01/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024]
Abstract
Flexible neural probes are attractive emerging technologies for brain recording because they can effectively record signals with minimal risk of brain damage. Reducing the electrode impedance of the probe before recording is a common practice of many researchers. However, studies investigating the impact of low impedance levels on high-quality recordings using flexible neural probes are lacking. In this study, we electrodeposited Pt onto a commercial flexible polyimide neural probe and investigated the relationship between the impedance level and the recording quality. The probe was inserted into the brains of anesthetized mice. The electrical signals of neurons in the brain, specifically the ventral posteromedial nucleus of the thalamus, were recorded at impedance levels of 50, 250, 500 and 1000 kΩ at 1 kHz. The study results demonstrated that as the impedance decreased, the quality of the signal recordings did not consistently improve. This suggests that extreme lowering of the impedance may not always be advantageous in the context of flexible neural probes.
Collapse
Affiliation(s)
- Juyeon Han
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
| | - Jungsik Choi
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
| | - Hyeonyeong Jeong
- Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Daerl Park
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
| | - Eunji Cheong
- Department of Biotechnology, Yonsei University, Seoul 03722, Republic of Korea
| | - Jaesuk Sung
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
| | - Heon-Jin Choi
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea; (J.H.)
- Nformare Inc., Seodamun-gu, Seoul 03722, Republic of Korea
| |
Collapse
|
3
|
Mintz Hemed N, Melosh NA. An integrated perspective for the diagnosis and therapy of neurodevelopmental disorders - From an engineering point of view. Adv Drug Deliv Rev 2023; 194:114723. [PMID: 36746077 DOI: 10.1016/j.addr.2023.114723] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/14/2022] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Neurodevelopmental disorders (NDDs) are complex conditions with largely unknown pathophysiology. While many NDD symptoms are familiar, the cause of these disorders remains unclear and may involve a combination of genetic, biological, psychosocial, and environmental risk factors. Current diagnosis relies heavily on behaviorally defined criteria, which may be biased by the clinical team's professional and cultural expectations, thus a push for new biological-based biomarkers for NDDs diagnosis is underway. Emerging new research technologies offer an unprecedented view into the electrical, chemical, and physiological activity in the brain and with further development in humans may provide clinically relevant diagnoses. These could also be extended to new treatment options, which can start to address the underlying physiological issues. When combined with current speech, language, occupational therapy, and pharmacological treatment these could greatly improve patient outcomes. The current review will discuss the latest technologies that are being used or may be used for NDDs diagnosis and treatment. The aim is to provide an inspiring and forward-looking view for future research in the field.
Collapse
Affiliation(s)
- Nofar Mintz Hemed
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Nicholas A Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
4
|
Ahnood A, Chambers A, Gelmi A, Yong KT, Kavehei O. Semiconducting electrodes for neural interfacing: a review. Chem Soc Rev 2023; 52:1491-1518. [PMID: 36734845 DOI: 10.1039/d2cs00830k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In the past 50 years, the advent of electronic technology to directly interface with neural tissue has transformed the fields of medicine and biology. Devices that restore or even replace impaired bodily functions, such as deep brain stimulators and cochlear implants, have ushered in a new treatment era for previously intractable conditions. Meanwhile, electrodes for recording and stimulating neural activity have allowed researchers to unravel the vast complexities of the human nervous system. Recent advances in semiconducting materials have allowed effective interfaces between electrodes and neuronal tissue through novel devices and structures. Often these are unattainable using conventional metallic electrodes. These have translated into advances in research and treatment. The development of semiconducting materials opens new avenues in neural interfacing. This review considers this emerging class of electrodes and how it can facilitate electrical, optical, and chemical sensing and modulation with high spatial and temporal precision. Semiconducting electrodes have advanced electrically based neural interfacing technologies owing to their unique electrochemical and photo-electrochemical attributes. Key operation modalities, namely sensing and stimulation in electrical, biochemical, and optical domains, are discussed, highlighting their contrast to metallic electrodes from the application and characterization perspective.
Collapse
Affiliation(s)
- Arman Ahnood
- School of Engineering, RMIT University, VIC 3000, Australia
| | - Andre Chambers
- School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Amy Gelmi
- School of Science, RMIT University, VIC 3000, Australia
| | - Ken-Tye Yong
- School of Biomedical Engineering, University of Sydney, Sydney, NSW 2006, Australia.,The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
| | - Omid Kavehei
- School of Biomedical Engineering, University of Sydney, Sydney, NSW 2006, Australia.,The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
| |
Collapse
|
5
|
Xu M, Zhao Y, Xu G, Zhang Y, Sun S, Sun Y, Wang J, Pei R. Recent Development of Neural Microelectrodes with Dual-Mode Detection. BIOSENSORS 2022; 13:59. [PMID: 36671894 PMCID: PMC9856135 DOI: 10.3390/bios13010059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/24/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Neurons communicate through complex chemical and electrophysiological signal patterns to develop a tight information network. A physiological or pathological event cannot be explained by signal communication mode. Therefore, dual-mode electrodes can simultaneously monitor the chemical and electrophysiological signals in the brain. They have been invented as an essential tool for brain science research and brain-computer interface (BCI) to obtain more important information and capture the characteristics of the neural network. Electrochemical sensors are the most popular methods for monitoring neurochemical levels in vivo. They are combined with neural microelectrodes to record neural electrical activity. They simultaneously detect the neurochemical and electrical activity of neurons in vivo using high spatial and temporal resolutions. This paper systematically reviews the latest development of neural microelectrodes depending on electrode materials for simultaneous in vivo electrochemical sensing and electrophysiological signal recording. This includes carbon-based microelectrodes, silicon-based microelectrode arrays (MEAs), and ceramic-based MEAs, focusing on the latest progress since 2018. In addition, the structure and interface design of various types of neural microelectrodes have been comprehensively described and compared. This could be the key to simultaneously detecting electrochemical and electrophysiological signals.
Collapse
Affiliation(s)
- Meng Xu
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| | - Yuewu Zhao
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
| | - Guanghui Xu
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| | - Yuehu Zhang
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| | - Shengkai Sun
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
| | - Yan Sun
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| | - Jine Wang
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| | - Renjun Pei
- CAS Key Laboratory for Nano-Bio Interface, Division of Nano-biomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou 215123, China
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China (USTC), Hefei 230026, China
| |
Collapse
|
6
|
Zhang M, Guo X. Gold/platinum bimetallic nanomaterials for immunoassay and immunosensing. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214578] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Sharafkhani N, Kouzani AZ, Adams SD, Long JM, Lissorgues G, Rousseau L, Orwa JO. Neural tissue-microelectrode interaction: Brain micromotion, electrical impedance, and flexible microelectrode insertion. J Neurosci Methods 2022; 365:109388. [PMID: 34678387 DOI: 10.1016/j.jneumeth.2021.109388] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/17/2021] [Accepted: 10/17/2021] [Indexed: 10/20/2022]
Abstract
Insertion of a microelectrode into the brain to record/stimulate neurons damages neural tissue and blood vessels and initiates the brain's wound healing response. Due to the large difference between the stiffness of neural tissue and microelectrode, brain micromotion also leads to neural tissue damage and associated local immune response. Over time, following implantation, the brain's response to the tissue damage can result in microelectrode failure. Reducing the microelectrode's cross-sectional dimensions to single-digit microns or using soft materials with elastic modulus close to that of the neural tissue are effective methods to alleviate the neural tissue damage and enhance microelectrode longevity. However, the increase in electrical impedance of the microelectrode caused by reducing the microelectrode contact site's dimensions can decrease the signal-to-noise ratio. Most importantly, the reduced dimensions also lead to a reduction in the critical buckling force, which increases the microelectrode's propensity to buckling during insertion. After discussing brain micromotion, the main source of neural tissue damage, surface modification of the microelectrode contact site is reviewed as a key method for addressing the increase in electrical impedance issue. The review then focuses on recent approaches to aiding insertion of flexible microelectrodes into the brain, including bending stiffness modification, effective length reduction, and application of a magnetic field to pull the electrode. An understanding of the advantages and drawbacks of the developed strategies offers a guide for dealing with the buckling phenomenon during implantation.
Collapse
Affiliation(s)
- Naser Sharafkhani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| | - Abbas Z Kouzani
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - Scott D Adams
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | - John M Long
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia
| | | | | | - Julius O Orwa
- School of Engineering, Deakin University, Geelong, VIC 3216, Australia.
| |
Collapse
|
9
|
Seaton BT, Heien ML. Biocompatible reference electrodes to enhance chronic electrochemical signal fidelity in vivo. Anal Bioanal Chem 2021; 413:6689-6701. [PMID: 34595560 DOI: 10.1007/s00216-021-03640-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/17/2022]
Abstract
In vivo electrochemistry is a vital tool of neuroscience that allows for the detection, identification, and quantification of neurotransmitters, their metabolites, and other important analytes. One important goal of in vivo electrochemistry is a better understanding of progressive neurological disorders (e.g., Parkinson's disease). A complete understanding of such disorders can only be achieved through a combination of acute (i.e., minutes to hours) and chronic (i.e., days or longer) experimentation. Chronic studies are more challenging because they require prolonged implantation of electrodes, which elicits an immune response, leading to glial encapsulation of the electrodes and altered electrode performance (i.e., biofouling). Biofouling leads to increased electrode impedance and reference electrode polarization, both of which diminish the selectivity and sensitivity of in vivo electrochemical measurements. The increased impedance factor has been successfully mitigated previously with the use of a counter electrode, but the challenge of reference electrode polarization remains. The commonly used Ag/AgCl reference electrode lacks the long-term potential stability in vivo required for chronic measurements. In addition, the cytotoxicity of Ag/AgCl adversely affects animal experimentation and prohibits implantation in humans, hindering translational research progress. Thus, a move toward biocompatible reference electrodes with superior chronic potential stability is necessary. Two qualifying materials, iridium oxide and boron-doped diamond, are introduced and discussed in terms of their electrochemical properties, biocompatibilities, fabrication methods, and applications. In vivo electrochemistry continues to advance toward more chronic experimentation in both animal models and humans, necessitating the utilization of biocompatible reference electrodes that should provide superior potential stability and allow for unprecedented chronic signal fidelity when used with a counter electrode for impedance mitigation.
Collapse
Affiliation(s)
- Blake T Seaton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA
| | - Michael L Heien
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, USA.
| |
Collapse
|
10
|
Boehler C, Carli S, Fadiga L, Stieglitz T, Asplund M. Tutorial: guidelines for standardized performance tests for electrodes intended for neural interfaces and bioelectronics. Nat Protoc 2020; 15:3557-3578. [DOI: 10.1038/s41596-020-0389-2] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/28/2020] [Indexed: 01/22/2023]
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Rodrigues F, Ribeiro JF, Anacleto PA, Fouchard A, David O, Sarro PM, Mendes PM. Fabrication and characterization of polyimide-based 'smooth' titanium nitride microelectrode arrays for neural stimulation and recording. J Neural Eng 2019; 17:016010. [PMID: 31614339 DOI: 10.1088/1741-2552/ab4dbb] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE As electrodes are required to interact with sub-millimeter neural structures, innovative microfabrication processes are required to enable fabrication of microdevices involved in such stimulation and/or recording. This requires the development of highly integrated and miniaturized systems, comprising die-integration-compatible technology and flexible microelectrodes. To elicit selective stimulation and recordings of sub-neural structures, such microfabrication process flow can beneficiate from the integration of titanium nitride (TiN) microelectrodes onto a polyimide substrate. Finally, assembling onto cuffs is required, as well as electrode characterization. APPROACH Flexible TiN microelectrode array integration and miniaturization was achieved through microfabrication technology based on microelectromechanical systems (MEMS) and complementary metal-oxide semiconductor processing techniques and materials. They are highly reproducible processes, granting extreme control over the feature size and shape, as well as enabling the integration of on-chip electronics. This design is intended to enhance the integration of future electronic modules, with high gains on device miniaturization. MAIN RESULTS (a) Fabrication of two electrode designs, (1) 2 mm long array with 14 TiN square-shaped microelectrodes (80 × 80 µm2), and (2) an electrode array with 2 mm × 80 µm contacts. The average impedances at 1 kHz were 59 and 5.5 kΩ, respectively, for the smaller and larger contacts. Both designs were patterned on a flexible substrate and directly interconnected with a silicon chip. (b) Integration of flexible microelectrode array onto a cuff electrode designed for acute stimulation of the sub-millimeter nerves. (c) The TiN electrodes exhibited capacitive charge transfer, a water window of -0.6 V to 0.8 V, and a maximum charge injection capacity of 154 ± 16 µC cm-2. SIGNIFICANCE We present the concept, fabrication and characterization of composite and flexible cuff electrodes, compatible with post-processing and MEMS packaging technologies, which allow for compact integration with control, readout and RF electronics. The fabricated TiN microelectrodes were electrochemically characterized and exhibited a comparable performance to other state-of-the-art electrodes for neural stimulation and recording. Therefore, the presented TiN-on-polyimide microelectrodes, released from silicon wafers, are a promising solution for neural interfaces targeted at sub-millimeter nerves, which may benefit from future upgrades with die-electronic modules.
Collapse
Affiliation(s)
- F Rodrigues
- CMEMS-UMinho, University of Minho, Braga, Portugal. Electronics Components, Technology, and Materials Lab, Else Kooi Laboratory, Delft University of Technology, Delft, The Netherlands. Author to whom any correspondence should be addressed
| | | | | | | | | | | | | |
Collapse
|
13
|
Gold-Plated Electrode with High Scratch Strength for Electrophysiological Recordings. Sci Rep 2019; 9:2985. [PMID: 30814648 PMCID: PMC6393511 DOI: 10.1038/s41598-019-39138-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/18/2019] [Indexed: 11/08/2022] Open
Abstract
Multi electrode arrays (MEA) have been exploited in different electrophysiological applications. In neurological applications, MEAs are the vital interfaces between neurons and the electronic circuits with dual role; transmitting electric signal to the neurons and converting neural activity to the electric signal. Since the performance of the electrodes has a direct effect on the quality of the recorded neuronal signal, as well as the stimulation, the true choice of electrode material for MEA is crucial. Gold is one of the best candidates for fabrication of MEAs due to its high electrical conductivity, biocompatibility and good chemical stability. However, noble metals such as gold do not adhere well to the glass substrate. Consequently while exposing to the water, gold films are damaged, which impose limitations in the exploiting of gold thin films as the electrode. In this paper, a simple and cost effective method for the fabrication of gold electrode arrays is proposed. Using various mechanical (adhesion test and scratch strength), morphological (AFM and SEM) and electrochemical methods, the fabricated electrodes are characterized. The results show that the fabricated electrode arrays have significantly high scratch strength and stability within the aqueous medium. In addition, the electrical properties of the electrodes have been improved. The proposed electrodes have the potential to be exploited in other applications including electronics, electrochemistry, and biosensors.
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|