Development of Transparent, Stretchable Organic Electrochemical Transistors for Bio signal Amplification

Transparent organic electrochemical transistors (OECTs) combine mechanical flexibility with low-voltage operation, enabling multimodal biophysical sensing when coupled to optical sensing. Conventional OECTs, however, rely on rigid metal films and thus lack stretchability. Here, we develop a fully stretchable, transparent OECT by utilizing Ag nanowires (AgNWs) and semiconducting polymer in a thin-layered polyurethane (PU) architecture that suppresses stress-induced failure. The OECT shows 87 % optical transmittance at 550 nm and transistor operation under 100 % strain. In addition, the device exhibits a transconductance of 1.74 mS and, in a simple amplifier, provides a 2.5-fold voltage gain. Therefore, the device promises utility in advanced wearable healthcare systems.