Super Tough Anti‐freezing and Antibacterial Hydrogel With Multi‐crosslinked Network for Flexible Strain Sensor

Addressing the diverse environmental demands for electronic material performance, the design of a multifunctional ionic conductive hydrogel with mechanical flexibility, anti-freezing capability, and antibacterial characteristics represents an optimal solution. Leveraging the Dead Sea effect and the strong hydrogen bonding, this study exploits the CaCl₂ and the abundant hydroxyl groups in phytic acid (PA) to induce chain entanglements, thereby constructing a complex, multi-crosslinked network. Furthermore, PA and ternary solvent systems (CaCl₂/Glycerol/H₂O) synergistically impart excellent mechanical strength, toughness (with tensile strength of 8.93 MPa, elongation at break of 859.93%, and toughness of 39.92 MJ m^-3), high electrical conductivity, antifreeze capability, antibacterial properties, and high strain sensitivity (gauge factor up to 2.10) to the hydrogels. Remarkably, the hydrogel structure maintains stability even after undergoing 6000 loading-unloading cycles, demonstrating its outstanding fatigue resistance. Upon receiving external stimuli, the hydrogel exhibits a response time of 126 ms, making it ideal for the dynamic monitoring of human motion signals. This study offers novel insight into the potential application of ionic conductive hydrogels as flexible sensors in challenging environments.