Pressure Sensor Based on an Organic Electrochemical Transistor with Modulation of Electrical-Double-Layer

In this study, we developed an organic electrochemical transistor (OECT)-type pressure sensor based on pressure-induced modulation of ions in an electrical-double-layer (EDL). The quantity of ions in the EDL, which forms at the interface of the ionic liquid gel, can be modulated by the physical pressure. This phenomenon is attributed to the migration of ions in the vicinity of the EDL due to external pressure and Coulomb forces, in addition to the mechanical deformation of the ionic liquid gel. Furthermore, using the OECT with ionic liquid gel, the modulation of the EDL by pressure was output as a change in current value. As a proof of concept, we realized a sensor that mimics the pressure sensing mechanism of the sense of touch, in which pressure is detected by a change in current.