Ionic conductive hydrogels toughened by latex particles for strain sensors

Conductive hydrogels have attracted tremendous attention due to their excellent softness and stretchability as wearable strain sensing devices. However, most of hydrogel-based strain sensors suffered from poor self-recoverability and fatigue resistance, resulting in significant decrease of strain sensitivity after recycling. Here, a soft and flexible wearable strain sensor is prepared by using an ionic conductive hydrogel with latex particles as physical cross-linking centers. The dynamic physical cross-linking structure can effectively dissipate energy through disruption and reconstruction of molecular segments, thereby imparting excellent stretchability, self-recoverability and fatigue resistance. In addition, the hydrogel exhibits excellent strain-sensitive resistance changes, which enables it to be assembled as a wearable sensor to monitor human motions. As a result, the hydrogel strain sensor can provide precise feedback for a wide range of human activities, including large-scale joint bending and tiny phonating. Therefore, the tough ionic conductive hydrogel would be widely applied in electronic skin, medical monitoring and artificial intelligence.