Conformal Vertical Organic Electrochemical Transistors With Ion‐Permeable Electrodes for Electrophysiological Monitoring

ABSTRACT Textile‐based organic electrochemical transistors (OECTs) offer unique advantages for wearable health monitoring, yet their performance is often limited by relatively slow ion dynamics. Here, we overcome this limitation by developing a conformal, nanofibrous vertical OECT (NF‐vOECT) platform fabricated via electrospinning. The device integrates vertically stacked semiconductor channels with, critically, ion‐permeable nanofiber electrodes. These porous electrodes facilitate direct vertical ionic exchange with the active layer, enabling highly efficient channel modulation while maintaining excellent breathability and mechanical adaptability. The resulting NF‐vOECTs exhibit a high transconductance of up to 57.5 mS, a fast response time of 11.7 ms, and stable low‐voltage operation, alongside robust mechanical and electrochemical durability. This architecture's amplification and frequency‐selective response contribute to an improved signal‐to‐noise ratio during real‐time electrophysiological signal acquisition. This work establishes a new platform for high‐performance, breathable OECTs, advancing the development of soft bioelectronics for next‐generation wearable applications.