High-sensitivity antidrying hydrogel sensor with interpenetrating network crosslinking structure

Flexible sensors for detecting strain have attracted the attention of many researchers. At present, it is an important research direction to prepare conductive hydrogels by adding different metal ions into hydrogels. In this study, a highly extensible and transparent ionic conductive hydrogel was prepared by one-step polymerization. Using sodium chloride as ionic conductive medium, interpenetrating network ionic conductive hydrogels with good flexibility, conductivity, and self-viscosity were constructed. The network is composed of graft copolymer polyacrylamide-acrylic acid (PAMAA) and biomass polymer sodium alginate (SA). Chemical and physical crosslinking have significant tensile properties for hydrogel. Because of the addition of sodium chloride, the hydrogel has excellent electrical conductivity. The SA/PAMAA-GL/NaCl conductive hydrogel can be adhered to different surfaces, such as glass, plastic, iron clip, copper sheet, and skin. The conductive hydrogel can be used as stress sensor, and the sensor is sensitive to the small strain and large strain. This conductive hydrogel has potential application prospects in flexible wearable electronic equipment, motion monitoring, medical rehabilitation, and other fields.