Graphene Fiber‐Based Bio‐Microelectrode for Precise Neural Signal Recording

ABSTRACT Accurate extraction of electrophysiological signals is crucial for advancing research into the pathogenesis of mental illnesses. Nevertheless, current physiological electrodes still face significant challenges, including modulus mismatch, poor biocompatibility, and suboptimal signal‐to‐noise ratio. It is well established that pore structure regulation is the key point to the preparation of high‐performance physiological electrodes. Herein, non‐liquid‐crystal spinning integrated with a shearing‐induced orientation process is employed for the fabrication of graphene fibers with an oriented porous structure, which exhibit high electrical conductivity (109.73 S cm −1 ), suitable interfacial impedance (14.23 Ω mm 2 ), and high charge storage capacity (82.89 mC cm −2 ). After coating with SiO 2 and hydrogel layers, the graphene fiber achieves electrical insulation of the side surface, preventing charge leakage, and establishes an adaptive interface that effectively reduces the interfacial modulus, respectively. Thus, it can serve as a bio‐microelectrode for the precise detection of neural activity in the targeted brain region, and the extracted electrophysiological signals possess a high signal‐to‐noise ratio of 12.83 dB. This work presents a scalable and synergistic strategy for constructing next‐generation bio‐microelectrodes, enabling high‐quality extraction of electrophysiological signals with relatively minor invasive injury.