Multilayer Double-Sided Microstructured Flexible Iontronic\nPressure Sensor with a Record-wide Linear Working Range

Abstract

Wearable electronics, electronic\nskins, and human–machine\ninterfaces demand flexible sensors with not only high sensitivity\nbut also a wide linear working range. The latter remains a great challenge\nand has become a big hurdle for some of the key advancements imperative\nto these fields. Here, we present a flexible capacitive pressure sensor\nwith ultrabroad linear working range and high sensitivity. The dielectric\nlayer of the sensor is composed of multiple layers of double-sided\nmicrostructured ionic gel films. The multilayered structure and the\ngaps between adjacent films with random topography and size enhance\nthe compressibility of the sensor and distribute the stress evenly\nto each layer, enabling a linear working range from 0.013 to 2063\nkPa. Also, the densely distributed protrusive microstructures in the\nelectric double layer contribute to a sensitivity of 9.17 kPa^–1 for the entire linear working range. For the first\ntime, a highly sensitive pressure sensor that can measure loading\nconditions across 6 orders of magnitude is demonstrated. With the\nconsistent and stable performance from a low- to high-measurement\nrange, the proposed pressure sensor can be used in many applications\nwithout the need for recalibration to suit different loading scenarios.