Anti-swelling and photoresponsive MXene-based polyampholyte hydrogel sensors for underwater positioning and urban waterlogging pre-warning

Abstract

Conductive hydrogels are viewed as the most promising materials for flexible devices. However, their applications in aquatic environments are severely limited by their inevitable swelling behavior. Herein, we report a MXene-based polyampholyte anti-swelling hydrogel possessing high stretchability (1391%), good conductivity, admirable self-healing ability (healing efficiency reached 66% after healing for 1 h), and fast photoresponsive behavior. Besides, the hydrogel-based sensor displayed a wide sensing range (2–400%) and could realize underwater monitoring and communication. More importantly, an underwater warning system was assembled, which can offer efficient real-time underwater positioning and urban waterlogging pre-warning. This work provides a new strategy for developing anti-swelling hydrogel sensors and expands their potential applications in marine exploitation and urban construction.