Biosafe, self-adhesive, recyclable, tough, and conductive hydrogels for multifunctional sensors

As a bioelectronic material used in personalized medicine, it is necessary to integrate excellent adhesion and stretchability in hydrogels for ensuring biosafety. Herein, a high-performance multifunctional hydrogel of polyvinyl alcohol-sodium alginate-g-dopamine-silver nanowire-borax (PSAB) is reported. It can not only easily adhere to the surface of various substrates, but also exhibit excellent mechanical properties. Its tensile strength, elongation at break and toughness are 0.286 MPa, 500% and 55.15 MJ m^-3, respectively. The excellent mechanical properties and high conductivity guarantee that the PSAB hydrogel can successfully serve as a multifunctional sensor for detecting small activities and large-scale movements of the human body through strain and pressure changes. Meanwhile, the long-lasting potent and broad-spectrum antibacterial activity, combined with good in vitro biocompatibility, guarantees the biological safety and non-toxicity of the PSAB hydrogel. These compelling features, such as high flexibility and elasticity, high adhesion, multi-functional sensing and recyclability, as well as biological safety, pave the way for the application of PSAB hydrogel e-skin in biomedicine.