Conformal PEDOT:PSS Microelectrode Arrays with Controllable Doping Level and High Structural Order for Electrocorticogram Recording

Flexible microelectrode arrays (MEAs) have emerged as promising tools for perceiving the brain's neural activity, while challenges related to limited mechanical compliance and electrochemical performance have hindered their further advancements. In this work, we propose a multistep galvanostatic approach for fabricating conformal MEAs modified with PEDOT:PSS, effectively improving interface conformability and enhancing bioelectric conductivity. By precisely optimizing multistep electrochemical parameters, uniform PEDOT:PSS layers with controllable doping level and high structural order are directly polymerized, resulting in high electrical conductivity and low impedance without any post-treatment. The flexible MEAs with low flexural rigidity featuring 16 channels successfully visualized and distinguished electrocorticogram signals in a rat model, demonstrating their high performance in neural recordings. This study presents a simple and efficient approach for fabricating flexible PEDOT:PSS-modified MEAs with high bioelectric conductivity, opening new possibilities for conformal neural interfaces.