High-strength antifreezing flexible conductive polyvinyl alcohol hydrogel sensors co-reinforced with silk porous mesh fabric and silk nanofibers

Hydrogel-based flexible strain sensors have an enormous potential for applications in wearable electronics, but currently, realizing excellent mechanical properties and electrical conductivity of sensors is difficult. In this work, polyvinyl alcohol (PVA) hydrogels were augmented with positively charged silk nanofibers (PCSNF) and PEDOT:PSS, and the resultant PVA-PEDOT:PSS-PCSNF hydrogel fabric showed remarkable mechanical properties (4.38 MPa) and elevated electrical conductivity. The presence of ethylene glycol (EG) in the hydrogel fabric imparts antifreezing properties and sustains electrical conductivity even at frigid temperatures (−18°C). In addition, EG contributes to the improvement of the electrical conductivity of PEDOT:PSS. This PVA-PEDOT:PSS-PCSNF hydrogel fabric can be used as a precise and reliable strain sensor for detecting diverse human motions and facial expressions. Significantly, the PVA-PEDOT:PSS-PCSNF hydrogel fabric strain sensor exhibits a gauge factor of 1.02 and exceptional durability, withstanding 400 elbow bends. This study introduces an innovative method for creating high-performance and resilient hydrogel-based flexible sensors. Graphical