Near–hysteresis-free soft tactile electronic skins for wearables and reliable machine learning

Significance We show a near–hysteresis-free piezoresistive sensor system from soft materials by using a method of generating unique three-dimensional nanoscale crack morphologies on metal-coated elastomeric microstructures. Our method addresses the major challenge of inherent electromechanical hysteresis faced by many electronic sensor skins using soft materials when large compressive pressures are applied. Piezoresistive sensors made from our flexible composite material track deformation with <3% hysteresis and can be reliably used as a healthcare wearable device for measuring pulse wave velocity on a small skin patch. We also showed that the low hysteresis enabled accurate and reliable single-touch classification of surface textures on textile surfaces for robotic applications.