(150z) Liquid-Metal Based Flexible Multi-Electrode Neural Array

Implantable microelectrode arrays are an essential tool for understanding the nervous system's electrophysiology, neural functionalities, and the foundation of neurological disorders. Recent efforts in bioelectronic medicine and electroceutical research aim to expand the scope of electrical recording and stimulation beyond neurological systems. Microelectrode arrays are commonly fabricated from gold, tungsten, and stainless steel coated with insulating materials to expose specific functional sites at the device-tissue interface. Although considerable progress has been made in electrode design, current devices can not retain consistent recording performance over long periods. Consequently, there is a demand for chronically reliable microelectrode recording arrays. Gallium (Ga) based liquid metals have emerged as a promising material for the design of future bioelectronic devices. Ga-based materials have minimal cytotoxicity and excellent electrical conductivity but limited biostability, which limits their compatibility with bioelectronic devices. Here we demonstrate an effective conductive polymer deposition strategy on the liquid metal surface to improve the biostability and electrochemical performance of Ga‐based liquid metals for use under physiological conditions. Poly(3,4-ethylenedioxythiophene):tetrafluoroborate (PEDOT: BF4) modified liquid metal surface significantly outperforms the liquid metal-based electrode in mechanical, biological, and electrochemical studies.