A Sub-1-V, Microwatt Power-Consumption Iontronic Pressure Sensor Based on Organic Electrochemical Transistors

Wearable and implantable pressure sensors are in great demand for personalized health monitoring. Pressure sensors with low operation voltage and low power-consumption are desired for energy-saving devices. Organic iontronic devices, such as organic electrochemical transistors (OECTs), have demonstrated great potential for low power-consumption bioelectronic sensing applications. The ability to conduct both electrons and ions, in addition to their low-operation voltage has enabled the widespread use of OECTs in different biosensing fields. However, despite these merits, OECTs have not been demonstrated for pressure sensing applications. This is because most OECTs are gated with aqueous electrolyte, which fails to respond to external pressure. Here, a low power-consumption iontronic pressure sensor is presented based on an OECT, in which an ionic hydrogel is used as a solid gating medium. The resultant iontronic device operated at voltages less than 1 V, with a power-consumption between ~ 101– $10^{3} \mu \text{W}$ , while maintaining a tunable sensitivity between 1 ~ 10 kPa−1. This work places OECTs on the frontline for developing low power-consumption iontronic pressure sensors and for biosensing applications.