A transparent stretchable sensor for distinguishable detection of touch and pressure by capacitive and piezoresistive signal transduction

Abstract

AbstractTransparent stretchable (TS) sensors capable of detecting and distinguishing touch and pressure inputs are a promising development in wearable electronics. However, realization of such a device has been limited by difficulties in achieving optical transparency, stretchability, high sensitivity, stability, and distinguishable responsivity to two stimuli simultaneously. Herein, we report a TS sensor in which touch and pressure stimuli can be detected and distinguished on a substrate with a stress-relieving three-dimensional (3D) microstructured pattern providing multidirectional stretchability and increased pressure sensitivity. The TS capacitive device structure is a dielectric layer sandwiched between an upper piezoresistive electrode of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/ionic liquid composite, which enables touch and pressure stimuli to be distinguished, and a lower electrode of metal/indium tin oxide/metal multilayer. The TS sensor array was demonstrated as a wearable input device for controlling a small vehicle. The TS touch-pressure sensor has great potential to be used as a multimodal input device for future wearable electronics.