Hydrogel-based wearable electronic devices have received increasing attention. However, the construction of underwater strain sensors remains a significant challenge because of the swelling of hydrogels in an aquatic environment. This work presents the fabrication of an anti-swellable hydrogel composed of polyvinyl alcohol (PVA), a copolymer of [2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl) ammonium hydroxide (SBMA) and 2-hydroxyethyl methacrylate. Interestingly, facile switch of the SBMA moiety from neutral to positively charged status at...
