Skin-inspired large area iontronic pressure sensor with ultra-broad range and high sensitivity

Abstract

The development of flexible electronics and intelligent wearable devices requires flexible electronic skin with broad-range high sensitivity and sufficient spatial resolution through high-level sensor integration. Inspired by both the ion migration behaviors and the high-density distribution of tactile mechanical receptors in human skin, microstructured iontronic force-sensitive films and in-plane interdigital electrodes are integrated to form skin-inspired large area iontronic pressure sensors. Furthermore, by introducing the pressure-dependent unit area capacitance (UAC), the theoretical model of the in-plane iontronic sensor is successfully built and all parameters of the device are systematically analyzed from theoretical and experimental perspectives to achieve high-performance sensors. Such skin-inspired iontronic sensors exhibit an unexpected high sensitivity (365 kPa−1), ultra-broad range (1.7 Pa-1000 kPa), and remarkable reproducibility (10000 cycles), together with a wonderful capability of large array sensors (32 ×32). Benefitting from the outstanding comprehensive performance, the potential application in health monitoring has been demonstrated and an intelligent footpad based on iontronic sensors has been fabricated to detect falling danger of humans. The skin-inspired in-plane iontronic pressure sensor provides a new approach to achieve high-performance large-scale array of E-skin, which delivers great potential applications in next-generation health monitoring and wearable electronics.