Preparation of PAMgA/GL/GO antifreeze conductive hydrogel for wearable strain sensor based on physically cross-linked network

Conductive hydrogels have promising prospects in wearable strain sensor applications. However, the complex and diverse application scenarios put forward higher requirements on the conductivity, anti-freezing, tensile, self-healing, adhesion, and moisture retention properties of the conductive hydrogel. In this study, a polymagnesium acrylate/glycerol/graphene oxide (PAMgA/GL/GO) conductive hydrogel is prepared by free radical polymerization method, with magnesium acrylate (AMgA) as the polymer monomer, glycerol (GL) as the antifreeze filler, and graphene oxide (GO) as the conductive filler. Adding GL not only enhances the antifreeze properties of the composite hydrogels but also improves the moisture retention. The addition of GO increases the conductivity and the gauge factor (GF) of the composite hydrogels. When the GO content is 0.6 wt.%, the PAMgA/GL/GO conductive hydrogel demonstrates excellent properties of antifreeze, conductivity, self-healing, adhesion, and sensitivity. These excellent properties make it suitable as a wearable strain sensor for accurately monitoring human joint movements and subtle physiological signals.