A bio-inspired self-recoverable polyampholyte hydrogel with low temperature sensing

Abstract

Hydrogel-based flexible sensors have been extensively investigated, but inevitably, some hydrogels will not work properly at low temperature or recover their original property after deformation. In this work, a polyampholyte hydrogel was successfully prepared by introducing zwitterionic monomers with hydrophobic association. The electrostatic interaction based on polyelectrolyte provides excellent stretchability, fatigue resistance and self-recovery. It was important that the hydrogel, as an excellent strain sensor, exhibited a high electrical conductivity of 0.041 S cm⁻¹, a low temperature resistance of −31.7 °C, and a high sensitivity in the strain range of 0–500%. The hydrogel sensor is used for human motion detection, including joint movement, vocalization, and walking. Predictably, the hydrogel will provide stable performance in a complex temperature environment and exhibited a wide range of applications in physiological signal monitoring, electronic skin and soft robots.