Flexible and Stretchable Organic Electrochemical Transistors for Physiological Sensing Devices.

Flexible and stretchable bioelectronics provides a biocompatible interface between electronics and biological systems and has received tremendous attention for in-situ monitoring of various biological systems. Considerable progress in organic electronics has made organic semiconductors, as well as other organic electronic materials, ideal candidates for developing wearable, implantable, and biocompatible electronic circuits due to their potential mechanical compliance and biocompatibility. Organic electrochemical transistors (OECTs), as an emerging member of organic electronic building blocks, exhibit considerable advantages in biological sensing due to the ionic nature at the base of the switch behavior, low driving voltage (<1 V) and high transconductance (in mS range). During the past few years significant progress in constructing flexible/stretchable OECTs (FSOECTs) for both biochemical and bioelectrical sensing has been reported. In this regard, to summarize major research accomplishments in this emerging field, this review first discusses structure and critical features of FSOECTs, including working principle, materials and architectural engineering. Next, a wide spectrum of relevant physiological sensing applications, where FSOECTs are the key components, are summarized. Last, major challenges and opportunities for further advancing FSOECT physiological sensors are discussed. This article is protected by copyright. All rights reserved.