Stretchable gelatin/silver nanowires composite hydrogels for detecting human motion

A stretchable gelatin/silver nanowires (GE-AgNWs) composite hydrogel with enhanced mechanical properties and electrical conductivity has been prepared through chemical grafting and physical crosslinking. By introducing thiol groups on the gelatin molecular chain, better interactions between the reinforcing AgNWs and the gelatin molecules in the hydrogel networks was established. The introduced AgNWs not only reinforced the hydrogels but also formed effective electrical pathways to endow the hydrogel with good conductivity. By using the “salting out” effect, additional physical crosslinks were introduced to the hydrogel network so that the composite hydrogel became stretchable. The resulting composite hydrogel was not only biocompatible, but could also be used as a strain sensor to detect multiple human motions. Hence, these hydrogels have the potential to be used in biosensors, electric skins, and health monitoring applications.