Deep eutectic solvent-mediated sunlight polymerization for rapid fabrication of degradable hydrogel-based wearable sensors

Current strategies for preparing conductive hydrogels (CHs) often inevitably encompass time-consuming gelation processes, toxic initiators, poor environmental tolerance, and degradability, limiting their broader application and increasing environmental burdens. Herein, we proposed a novel sunlight-driven self-polymerization system for CH preparation that eliminates the need for initiators and chemical crosslinkers. Benefiting from the distinctive characteristics of novel deep eutectic solvents (DES) consisted of glycerol and 3-(benzyldimethylammonio)propane-1-sulfonate (SP), the hydrogel formation occurs within 10 min at room temperature. The resulting hydrogels demonstrated high stretchability (up to 1163 %), favorable elasticity, reliable adhesion (35.7 kPa to paper), impressive environmental tolerance (withstand-70 degrees C and long-term RT storage for 14 days), and excellent antibacterial properties. This comprehensive performance enables the CHs to serve as versatile wearable sensors for real-time monitoring of diverse stains and human movements (response time = 110 ms). Moreover, the physically crosslinked network allows them to degrade in saline solutions (within 42 h) due to the electrostatic inhibiting effects of Na+ and Cl- ions. Our work shed light on an eco-friendly and cost-effective method for customizing CHs, paving the way for innovative wearable devices that meet the sustainability demands for degradable electronic devices.