A conductive polyacrylamide/double bond chitosan/polyaniline hydrogel for flexible sensing

Flexible strain sensors, based on their good electrical conductivity and strain sensitivity, are widely used in wearable health monitoring, sensitive tactile information display and multi-functional robot skin. However, it is still a challenge for wearable devices to prepare conductive hydrogel with flexibility, high strain, high sensitivity and biocompatibility. Herein, we designed an interpenetrating network conductive composite hydrogel, which composed with polyaniline, double bond modified chitosan and acrylamide, has excellent strength and toughness due to its unique physically and chemically cross-linked double network. The obtained hydrogel exhibited good tensile strength (0.3 MPa), high electrical conductivity (6.97 S/m) and strain sensitivity (gauge factor 15.9). The results showed that the strain sensor could detect the movement of human joints through electrical signals, and had good stability and reproducibility, which indicated that it was expected to be used in wearable health monitoring and multi-functional robot skin.