Facile preparation and performance of flexible sensors based on polyacrylamide/carboxymethylchitosan/tannin acid hydrogels

Hydrogel flexible sensors are gaining significant interest due to their distinct biocompatibility, flexibility, and unique features of being adjustable and injectable, but there are still problems of poor self-healing performance and low conductivity in the current stage of research. In this work, a prefabricated blending method was used to construct a dual-network system using polyacrylamide (PAM), carboxymethyl chitosan (CMCS), and tannin acid (TA), and ferric ions (Fe³⁺) were introduced to apply ionically conductive organic hydrogels to flexible sensors. The PAM/CMCS-Fe³⁺/TA hydrogels have good fatigue resistance and self-healing properties, and their conductivity is as high as 6.42 S/m. This hydrogel-based sensor for strain sensing purpose offers a lot of promise for flexible sensor applications since it can provide steady, dependable, and repeatable electrical impulses.