PVA/SA/MXene dual-network conductive hydrogel for wearable sensor to monitor human motions

Conductive hydrogels with high flexibility, superior formability, good mechanical elasticity, and excellent biocompatibility have emerged as promising materials for broad applications in flexible/wearable electronic devices. In this work, a conductive dual-network PVA/SA/MXene hydrogel (PSM-h) composed of polyvinyl alcohol, sodium alginate, and MXene (Ti3C2Tx) is constructed by a green method without using chemical crosslinking agents. The resultant hydrogel with dual-network feature shows excellent cytocompatibility (no toxicity for human umbilical cord mesenchymal stem cells), high stretchability (up to 263%), and superior anti-fatigue ability (stretched up to 1000 cycles). More importantly, PSM-h based strain sensor presents good sensing sensitivity with a fast response time (62.5 ms) and a low detection limit even under a very slight strain of 0.2%. In terms of the practical application, the PSM-h based strain sensor can be applied to detect and distinguish various human motions.