Bioinspired Dynamic Cross-Linking Hydrogel Sensors with Skin-like Strain and Pressure Sensing Behaviors

Abstract

Biomimetic skin-like electric materials have been rapidly developed for human–machine interfaces, health monitoring, and soft robots. However, achieving a combination of mechanical and sensory properties like those of human skin remains a challenge. Here, a bioinspired physical cross-linking hydrogel sensor is designed and fabricated on the basis of an ionic conductive hydrogel with hybrid latex particles in a physically cross-linked network. The hydrogels exhibit excellent mechanical adaptability similar to that of human skin, including a low modulus, excellent stretchability, robust elasticity, rapid self-recoverability, and a good antifatigue property. Moreover, the addition of LiCl gives the hydrogel ideal ionic conducive behavior as a high-performance wearable sensor. The hydrogel-based sensor exhibits high sensitivity (GF = 5.44) over a broad strain window (0.25–2000%), excellent pressure sensing capability, a rapid response time, negligible hysteresis, and good durability. As a result, the hydrogel sensor can monitor various human motions, including large-scale joint bending, running and jumping, and tiny phonating and breathing. Therefore, the strategy will broaden the path for the new generation of biomimetic sensors with skin-like mechanical and strain and pressure sensing performances.