High Performance Organic Electrochemical Transistors via PVA-Doped PEDOT:PSS and Vertical Structure Synergy for Electrophysiological Sensing

Accurate acquisition of weak electrophysiological signals such as electrocardiography (ECG), electroencephalography (EEG), and electrooculography (EOG) is critical for healthcare monitoring yet remains technically challenging because electrophysiological signals exhibit inherently low amplitudes, narrow bandwidths, and high susceptibility to external interference. Organic electrochemical transistors (OECTs), with their high transconductance (gm) and low-voltage operation, offer a promising platform for electrophysiological signal amplification. Herein, we develop high-performance vertical OECTs (vOECTs) based on poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/poly(vinyl alcohol) (PEDOT:PSS/PVA) blends for multimodal electrophysiological signal acquisition. The introduction of PVA effectively tailors the microstructure and enhances ion-electron transport, yielding a peak gm of 113 mS and sub-3 ms response time. The devices exhibit linear amplification of sinusoidal signals across a broad physiological frequency range and maintain the waveform and temporal fidelity of ECG, EEG, and EOG waveforms with minimal distortion. Compared to previously reported OECTs, the vOECTs achieve 23-fold to 450-fold gain enhancements. These results demonstrate a scalable and high-fidelity signal amplification strategy, paving the way for next-generation wearable bioelectronic systems.