Environment-tolerant gelatin based ionic conductive organohydrogel for flexible sensor

Flexible wearable devices based on hydrogels have attracted more and more attention, however, the preparation of hydrogels with high toughness, conductivity and anti-freezing and anti-drying is still a challenge. In this study, a chemical-physical cross-linked double network conductive organohydrogel was designed by incorporating gelatin and Lithium chloride (LiCl) into polyacrylamide (AM) network with water-glycerol binary solvent. The results displayed that the organohydrogel exhibited high toughness, high stretchability, anti-freezing and anti-drying capability. With the addition of glycerol and LiCl, the organohydrogel has shown good conductivity in wide ranges of temperature. Moreover, the organohydrogel could be used as a strain sensor for the detection of various human body motions. Meanwhile, it was found that the introduction of LiCl enhanced the strain sensing performance, the stability and working temperature range. The sensors exhibited a high thermal sensitivity (5.72 % /℃), broad temperature detection range (0–65℃). These outstanding advantages indicated that the organohydrogels have potential application as strain and temperature sensors.