Extreme Temperature-Tolerant Conductive Gel with Antibacterial Activity for Flexible Dual-Response Sensors

Flexible sensors based on conductive hydrogel show great potential in electronic skin and human–machine interface. However, pure water in hydrogel inevitably freezes or rapidly evaporates under extreme temperatures, leading to inadequate fulfillment of sensor performances. Herein, a well-designed strategy is reported for fabricating extreme temperature-tolerant gel-based sensors. By immersing a gelatin/polyacrylamide (PAAm)–clay composite (GC) hydrogel into a ZnCl2/water/glycerol system, a phase-transition-tunable gel (PTTGC gel) is obtained with outstanding antifreezing (−82 °C) and long-lasting moisture (70 °C, more than 40 days) properties. Meanwhile, the gel also presents good antibacterial activity and biocompatibility attributing to Zn2+ and gelatin, respectively. Then, a dual-response sensor with a wide operating temperature (−60 to 60 °C) is proposed, presenting high stress and temperature sensitivities and long-term stability. The sensor will meet the needs of the human–machine interface for scientific investigation and data monitoring in polar, desert, etc.