Photo-crosslinking ionic conductive PVA-SbQ/FeCl3 hydrogel sensors

Conductive hydrogels are attracting intensive attention as promising materials for versatile applications such as human motion sensors, sensory skin and soft robotics. However, traditional hydrogels with single-network always have poor mechanical properties, while those with double-network are difficult to be prepared and inevitable to utilize chemical crosslinking agents which are poisonous. Herein, a polyvinyl alcohol bearing styrylpyridinium group (PVA-SbQ) /FeCl3 hydrogel sensor with unique double-crosslinked single network was prepared by UV photo-crosslinking and ionic coordination interaction. The PVA-SbQ/FeCl3 hydrogel possessed remarkable stretchability (~858%), good tensile stress (~0.3 MPa), high ionic conductivity (0.29 S/m), fine sensitivity, and excellent water retention ability due to the photo-crosslinking, physical crosslinking and hydrogen bond interaction worked in tandem and the introduction of Fe3+ ions. These properties endowed the PVA-SbQ/FeCl3 hydrogel with the potential for practical applications as flexible electronic components.