A novel thermogalvanic hydrogel-based e-skin is developed for self-powered dual-mode temperature and strain sensing. The hydrogel utilizes the iodine/triiodide (I⁻/I₃⁻) redox couple, which is common in disinfectants, and combines thermoelectric conversion with the inherent piezoresistive effect of a gel electrolyte. The hydrogel, synthesized from polyvinyl alcohol (PVA) monomers using a freeze-thaw method, exhibits flexibility, stretchability, and adaptability to human tissue. The incorporation of zwitterions enhances the hydrogel's resistance to dehydration and low temperatures, allowing it to retain over 90% of its weight after 48 hours in the air. The hydrogel is encapsulated and integrated onto various body areas, including the cheeks, fingers, and elbows, demonstrating its ability to detect temperature and strain. The hydrogel's thermogalvanic effect generates a continuous electric current under a temperature gradient, while its piezoresistive effect enables strain sensing. The hydrogel's thermoelectric performance is evaluated, showing a high Seebeck coefficient and conductivity. The hydrogel's ability to detect temperature and strain is validated through experiments, including monitoring of head-down states and foot movements. The hydrogel's dual-mode sensing capabilities are applied in healthcare, motion monitoring, and virtual reality. The hydrogel's self-powered sensing system offers new possibilities for wearable intelligent electronics and robotics. The hydrogel's performance is tested under various conditions, including dehydration, mechanical strain, and temperature differences, demonstrating its robustness and reliability. The hydrogel's ability to detect temperature and strain is further validated through applications on the cheeks, fingers, and elbows, showing its potential for monitoring neck posture and activity status. The hydrogel's dual-mode sensing capabilities are also demonstrated in robotic applications, where it can detect external heat sources and respond to their contact duration. The hydrogel's performance is compared with other hydrogel sensors, highlighting its promising attributes. The study concludes that the hydrogel-based e-skin provides effective guidance for developing good lifestyle habits and healthcare.A novel thermogalvanic hydrogel-based e-skin is developed for self-powered dual-mode temperature and strain sensing. The hydrogel utilizes the iodine/triiodide (I⁻/I₃⁻) redox couple, which is common in disinfectants, and combines thermoelectric conversion with the inherent piezoresistive effect of a gel electrolyte. The hydrogel, synthesized from polyvinyl alcohol (PVA) monomers using a freeze-thaw method, exhibits flexibility, stretchability, and adaptability to human tissue. The incorporation of zwitterions enhances the hydrogel's resistance to dehydration and low temperatures, allowing it to retain over 90% of its weight after 48 hours in the air. The hydrogel is encapsulated and integrated onto various body areas, including the cheeks, fingers, and elbows, demonstrating its ability to detect temperature and strain. The hydrogel's thermogalvanic effect generates a continuous electric current under a temperature gradient, while its piezoresistive effect enables strain sensing. The hydrogel's thermoelectric performance is evaluated, showing a high Seebeck coefficient and conductivity. The hydrogel's ability to detect temperature and strain is validated through experiments, including monitoring of head-down states and foot movements. The hydrogel's dual-mode sensing capabilities are applied in healthcare, motion monitoring, and virtual reality. The hydrogel's self-powered sensing system offers new possibilities for wearable intelligent electronics and robotics. The hydrogel's performance is tested under various conditions, including dehydration, mechanical strain, and temperature differences, demonstrating its robustness and reliability. The hydrogel's ability to detect temperature and strain is further validated through applications on the cheeks, fingers, and elbows, showing its potential for monitoring neck posture and activity status. The hydrogel's dual-mode sensing capabilities are also demonstrated in robotic applications, where it can detect external heat sources and respond to their contact duration. The hydrogel's performance is compared with other hydrogel sensors, highlighting its promising attributes. The study concludes that the hydrogel-based e-skin provides effective guidance for developing good lifestyle habits and healthcare.