Highly sensitive and high strength hydrogel sensors with interpenetrating network structure for strain-stimulus detection

The strength of the traditional hydrogel sensor is low, which limits its application. Here, a high strength wearable strain sensor is made of a flexible hydrogel with interpenetrating network cross-linking structure. The hydrogel consists of silica, sodium chloride, polyacrylic acid, sodium alginate and polyacrylamide in water solvent. The strength of the hydrogel is greatly improved by using silica emulsion as reinforcing filler. Due to the doping of sodium chloride (NaCl), the hydrogel has excellent ionic conductivity. The hydrogel doped with NaCl (0.1 g) and M-SiO2 (355 & mu;L) shows excellent mechanical and electrical properties, the tensile strength is 1.46Mpa, the elastic modulus is 615 kPa, and the toughness is 2578 kJ/m3. Conductive hydrogel as a strain sensor has good strain sensing properties and can be used to detect human motion in real time. In addition, the hydrogel maintains good flexibility, stretching, sensing and electrical conductivity in the wider strain range of 5-40%, which effectively improves the practicability and durability of hydrogels in practical applications. Therefore, the flexible, conductive and high strength hydrogel may have broad application prospects in the field of wearable devices and health detection systems.