Surface‐Grafted Biocompatible Polymer Conductors for Stable and Compliant Electrodes for Brain Interfaces

• DOI: 10.1002/adhm.202402215
• Publication Date: 2024-07-16T09:38:15Z
• Authors: Rachel Blau; Samantha M. Russman; Yi Qie; Wade Shipley; Allison Lim; Alexander X. Chen; Audithya Nyayacha...; Louis Ah; Abdulhameed Abdal; Guillermo L. Esparza; Samuel J. Edmunds; Ritwik Vatsyayan; Sean P. Dunfield; Moumita Halder; Jesse V. Jokerst; David P. Fenning; Andrea R. Tao; Shadi A. Dayeh; Darren J. Lipomi
• Keywords: Atom-transfer radical-polymerization; Polymer brush; Bioelectronics

Abstract Durable and conductive interfaces that enable chronic high‐resolution recording of neural activity are essential for understanding treating neurodegenerative disorders. These implants require long‐term stability small contact areas. Consequently, they often coated with a blend polymers crosslinked to enhance durability despite the potentially deleterious effect crosslinking on mechanical electrical properties. Here grafting poly(3,4 ethylenedioxythiophene) scaffold, poly(styrenesulfonate)‐ b ‐poly(poly(ethylene glycol) methyl ether methacrylate block copolymer brush gold, in controlled tunable manner, by surface‐initiated atom‐transfer radical polymerization (SI‐ATRP) is described. This “block‐brush” provides high volumetric capacitance (120 F cm ─3 ), strong adhesion metal (4 h ultrasonication), improved surface hydrophilicity, against 10 000 charge–discharge voltage sweeps multiarray electrode. In addition, block‐brush film showed 33% current pulsing. approach can open numerous avenues exploring specialized polymer brushes bioelectronics research application.