Ultrathin Bioelectrode Array with Improved Electrochemical Performance for Electrophysiological Sensing and Modulation

To achieve high accuracy and effectiveness in sensing and modulating neural activity, efficient charge-transfer biointerfaces and a high spatiotemporal resolution are required. Ultrathin bioelectrode arrays exhibiting mechanical compliance with biological tissues offer such biointerfaces. However, their thinness often leads to a lack of mechano-electrical stability or sufficiently high electrochemical capacitance, thus deteriorating their overall performance. Here, we report ultrathin (∼115 nm) bioelectrode arrays that simultaneously enable ultraconformability, mechano-electrical stability and high electrochemical performance. These arrays show high opto-electrical conductivity (2060 S cm