Dynamic Modulation of OECT‐Based Inverters for In Situ Electrophysiological Monitoring

Abstract Organic electrochemical transistors (OECTs) and their related circuits have emerged as a promising platform for biosensors and neuromorphic electronics, benefiting from their sub‐1 V operation voltage, flexibility, biocompatibility, etc. However, operation instability, induced by complex microstructure variations and undesired side reactions during repeated redox processes, poses tremendous challenges for reliable and robust functions. Here, a dynamic modulating system is presented that can actively control the working condition of an OECT‐based inverter and maintain high‐voltage amplification capability through real‐time voltage transfer characteristic scanning and operating voltage adjustment. Especially, under system modulation, the inverter maintains a high‐voltage amplification capability with a voltage gain >34.58 V V −1 . While without modulation (i.e., at a fixed input voltage), the voltage gain rapidly deteriorates to 3.11 V V −1 . Thereafter, stretchable complementary circuits are fabricated and integrated with this system to enable high‐fidelity in situ monitoring of the electrooculogram with >32.59 dB signal‐to‐noise ratio for more than 90 min, thus establishing a reliable wearable biosensing method. This work provides a new strategy to enable highly stable operation of bioelectronics with devices holding inferior stabilities.