Environmentally stable, highly stretchable strain sensor based on a conductive single-network hydrogel with non-drying and adhesive properties

Conductive hydrogels inevitably face dehydration, which deteriorates the conductive and tensile properties. Herein, a single-network hydrogel was constructed via the free-radical polymerization of 3-acrylamidopropyl trimethylammonium chloride (ATAC) and 2-hydroxyethyl methacrylate (HEMA) to enhance stretchability and adaptability to the environment. The single-network hydrogel exhibited excellent mechanical properties (fracture strain of 1812.96 %, fracture stress of 124.80 kPa, Young’ s modulus of 73.29 kPa, and toughness of 1426.01 KJ m−3) due to the existence of abundant hydrogen bonds. ATAC can suppress the vaporization of water by breaking the hydrogen bonds between water molecules, endowing the hydrogel with anti-drying performance and greatly broadening its application fields. This work provides a facile strategy for the construction of a single-network hydrogel with high stretchability, ion conductivity, adhesive and non-drying properties and offers new insights into the design of wearable sensors applicable in open environments.