Bending sensor using ionic liquid crystal elastomers as solid electrolyte of organic electrochemical transistors

Organic Electrochemical Transistors (OECTs) have the potential to enable fully flexible, low-cost electronics. Here, we demonstrate that OECTs can be combined with ionic liquid crystal elastomers (iLCEs) to realise highly sensitive bending sensors. The transfer curve of the iLCE-based OECT shows opposite variation with upward and downward bending representing a directional sensitive strain sensor. The change in the drain current is 4 orders of magnitude larger than the flexo-ionic current. This high sensitivity is due to the OECT that amplifies the flexo-ionic current. iLCE-based OECTs therefore present a new class of curvature sensors that may find applications in soft robotics and biosensing.