Ultrasensitive Piezoresistive Pressure Sensors Based on Interlocked Micropillar Arrays

Abstract

The development of wearable electronic skins is drawing many interests due to potential applications in prosthetic limbs, robotic skins, and human healthcare monitoring devices. Here, we demonstrate piezoresistive wearable electronic skins based on conductive composite elastomers with interlocked geometry of micropillar arrays. The interlocked micropillar arrays enable the huge variation of contact area and thus the contact resistance between interlocked micropillar arrays when they are deformed in response to external pressure stimuli. In this study, we show that the contact resistance is strongly affected by the variation of diameter, pitch size, and shape of micropillar arrays. The pressure sensor with optimized micropillar dimension shows an ultrahigh pressure sensitivity (−22.8 kPa−1) and response time (∼0.07 s). Finally, we demonstrate that the wearable electronic skin attached on the fingertip is capable of detecting the pressure and vibration signal simultaneously.