Toward Ideal Biointerfacing Electronics Using Organic Electrochemical Transistors

The biointerface between biological tissues and electronic devices serves as a medium for matter transport, signal transmission, and energy conversion. However, significant disparities in properties, such as mechanical modulus and water content, between tissues and electronics, present a key challenge in bioelectronics, leading to biointerface mismatches that severely impact their performance and long-term stability. Organic electrochemical transistors (OECTs), fabricated with soft, hydrophilic organic semiconductors, offer unique advantages, including low operating voltage, high transconductance, and compatibility with aqueous environments. These attributes position OECTs as promising candidates for ideal biointerfaces. As neural probes, OECTs have demonstrated superior biocompatibility and signal detection capabilities compared to conventional metal electrodes and inorganic semiconductors. Despite these advantages, the applications of OECT as biointerfaces remain constrained by several limitations, including limited performance, poor stability, mismatches among p-type, n-type, and ambipolar semiconductors, relatively high Young’s modulus, and unsatisfactory biointerfacial properties.