Preparation and characterization of self-healable and wearable hydrogels with ultrasensitive sensing performances

Conductive hydrogels with multifunction have received significant attention in the field of wearable electronic devices, especially in strain sensors and pressure sensors. The high sensor sensitivity, flexibility and mechanical strength are the top three critical factors for manufacturing of trustworthy sensors for practical applications. However, the conductive hydrogels are subjected to some limitations due to the lack of self-repair ability when damaged by external force, the low electrical conductivity and weak mechanical strength. To address these issues, multifunctional conductive hydrogels incorporating MXene nanosheets and lignin amine-silver nanoparticles (LA-Ag NPs) were constructed via a dynamic redox system. Benefiting from the introduction of MXene and LA-Ag NPs, the hydrogels demonstrated strong adhesiveness, self-healing property and high conductivity. Notably, the epidermal sensors demonstrated high sensitivity over a broad range as both strain sensor (GF = 9.17) and pressure sensor (S = 0.33 kPa−1).