Guar gum/gellan gum interpenetrating-network self-healing hydrogels for human motion detection

Hydrogel-based strain sensors have attracted increasing interest due to their high biocompatibility and stretch-ability. However, it is still a challenge to prepare hydrogel-based strain sensors with fast self-healing, high repeatability, and biocompatibility. Here, interpenetrating network (IPN) hydrogels based on natural polysaccharides were fabricated by introducing borate and hydrogen bonds. The IPN hydrogels with appropriate gellan gum (Gg), borax, and guar gum (GG) concentrations show good tensile properties, i.e., the fracture strength and elongation at break could reach to 28.2 kPa and 216%, respectively. Due to the dynamic reversibility of borate and hydrogen bonds, the IPN hydrogels also exhibit excellent self-healing properties. In addition, the introduction of borate ions allows the IPN hydrogels to conduct electricity. Therefore, the deformation of the IPN hydrogels can produce an electrical signal with excellent repeatability and reliability. As a result, the IPN hydrogels with excellent mechanics, self-healing and electrical conductivity may have great potential in human motion monitoring, intelligent wearable devices, etc.