Engineering Electrodes with Robust Conducting Hydrogel Coating for Neural Recording and Modulation. Issue 3 (16th December 2022)

• Record Type: Journal Article
• Authors: Zhang, Jiajun; Wang, Lulu; Xue, Yu; Lei, Iek Man; Chen, Xingmei; Zhang, Pei; Cai, Chengcheng; Liang, Xiangyu; Lu, Yi; Liu, Ji
• Is Part Of: Advanced materials. Volume 35:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-16
• Subjects: conducting polymer hydrogel -- electrical simulation -- interface -- neural recording -- robustness; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202209324
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Coating conventional metallic electrodes with conducting polymers has enabled the essential characteristics required for bioelectronics, such as biocompatibility, electrical conductivity, mechanical compliance, and the capacity for structural and chemical functionalization of the bioelectrodes. However, the fragile interface between the conducting polymer and the electrode in wet physiological environment greatly limits their utility and reliability. Here, a general yet reliable strategy to seamlessly interface conventional electrodes with conducting hydrogel coatings is established, featuring tissue‐like modulus, highly‐desirable electrochemical properties, robust interface, and long‐term reliability. Numerical modeling reveals the role of toughening mechanism, synergy of covalent anchorage of long‐chain polymers, and chemical cross‐linking, in improving the long‐term robustness of the interface. Through in vivo implantation in freely‐moving mouse models, it is shown that stable electrophysiological recording can be achieved, while the conducting hydrogel–electrode interface remains robust during the long‐term low‐voltage electrical stimulation. This simple yet versatile design strategy addresses the long‐standing technical challenges in functional bioelectrode engineering, and opens up new avenues for the next‐generation diagnostic brain‐machine interfaces. Abstract : Bioelectrodes with Robust Conducting Hydrogel Coating for Neural recording and Modulation: Bioelectrodes are engineered with a conducting hydrogel layer, featuring robust interfacial adhesion, long‐term reliability, highly‐desirable electronic conductivity, and mechanical compliance, for long‐term electrophysiological recordings of neural activities and low‐voltage electrical stimulation.