Dynamically cross-linked PVA hydrogel reinforced with poly(γ-glutamic acid) for highly Stretchable and rapidly...

The convergence of big data, the Internet of Things (IoT), and artificial intelligence (AI) has spurred an escalating demand for portable devices, thereby driving active research into hydrogel-type strain sensors that are capable of versatile attachment and movement monitoring. Among such strain-sensing materials, poly(vinyl alcohol) and borax are prominent due to their dynamic reversible bonding, which facilitates rapid gel formation and self-healing. In the present study, multifunctional conductive hydrogels are synthesized based on poly(vinyl alcohol), borax, poly(γ-glutamic acid), and tannic acid. The resulting PBGT hydrogels exhibit remarkable elasticity of >500%, along with swift self-recovery from external damage and stable adhesion to diverse interfaces such as pig skin and polyethylene terephthalate (PET) film. Moreover, they display high sensitivity, with gauge factors of 1.31 and 0.61 at deformations of 10-100% and 200-1000%, respectively. Due to these properties, the PBGT hydrogels hold promise for application as strain sensors for monitoring human movements across various scales or as touch panels. Furthermore, integration into a single-electrode triboelectric nanogenerator (TENG) yields a voltage output of 0.437 V, thereby underscoring the potential of these hydrogels as self-powered, intelligent, and flexible electronic materials.