The anti-swelling, freezing resistant and high strength PVA organohydrogel combined with multifunctional {Mo154} for sensitive and wide-range strain sensing

Maintaining the detection stability of flexible strain sensors in a cold environment presents a significant challenge due to the sharp reduction of mechanical properties under harsh conditions, potentially resulting in sensor failure. To address this problem, it is crucial to develop a conductive material with stable mechanical properties across both mild and low temperatures. Herein, based on the conductivity and photothermal conversion ability of {Mo 154 } clusters, it was blended with the binary solvents (DMSO and water) dissolved PVA to construct the functional Mo-PVA/DW organohydrogel. In the gel, {Mo 154 } also offered abundant crosslinking points with PVA to maintain the original state in the liquid condition and at a low temperature of −20 °C. Depending on the favorable conductivity of 1.15 × 10 -3 S/cm, the Mo-PVA/DW-based flexible sensor displayed fast and repeatable response of motion detection at both −20 and 20 °C. In addition, the good photothermal conversion capability of Mo-PVA/DW organohydrogel can also give assistance to the strain sensor in the cold environment through the sunlight irradiation, immensely expanding the potential application scenarios.