Conductive and eco-friendly gluten/MXene composite organohydrogels for flexible, adhesive, and low-temperature tolerant epidermal strain sensors

Abstract

Conductive hydrogels have drawn tremendous attention in the field of artificial intelligence, health monitoring, and soft robotics. However, combining hydrogels with conductivity, self-adhesiveness, low-temperature tolerance, biocompatibility, and biodegradability in green and low-cost ways remains a great challenge. Hence, the conductive MXene nanosheets were introduced into gluten networks by simple cooking inspired processes and solvents exchanged with glycerol/water binary solution to fabricate conductive organohydrogels (GMOHx). The GMOHx were conductive (5 ×10−4 S/m), flexible, adhesive to various surfaces (a max lap-shear strength of ~ 45.9 KPa), low-temperature tolerant (conductive and flexible under −20 °C), biocompatible, and easily degradable (degraded in neutral proteinase dispersion within 2 days), which can be applied as epidermal strain sensors to detect both large (e.g., elbow, wrist, and knee bending) and subtle (e.g., swallowing) scale human motions with accurate and long-term stable signals even under sub-zero temperatures.