A highly sensitive and flexible capacitive pressure sensor based on an ionic hydrogel dielectric layer with a lateral-bending microstructure

Abstract

This study presents the development of a highly sensitive and flexible capacitive pressure sensor utilizing an ionic hydrogel dielectric layer with a lateral-bending microstructure. The lateral-bending microstructure was inspired by the deformation response of grass under pressure, which exhibits localized deformation under slight compressive loads. This unique design results in enhanced sensitivity at low pressures (<1 kPa), achieving a sensitivity of 2.79 kPa⁻¹, significantly outperforming other microstructures. The sensor maintains stable signal changes even after 13 000 cycles of loading stress tests, demonstrating robust reliability and a wide working range from 78 Pa to 11 kPa. The biocompatibility of ionic hydrogels suggests their potential applications in wearable biosensors for monitoring human motion. The digital light processing technique allows for the rapid and cost-effective fabrication of microstructures, contributing to the high performance and versatility of sensors. This research opens new possibilities for the development of intelligent wearable devices with precise tactile sensing capabilities.