Stretchable adhesive eutectic organohydrogel based on gelatin-Quaternized chitosan for wearable human motion...

Hydrogels are promising materials for flexible wearable electronics, yet their low adhesiveness, poor environmental stability, and weak mechanical properties limit practical applications. Herein, we design a multi-network eutectic organohydrogel based on a deep eutectic solvent (DES) composed of choline chloride (ChCl) and acrylamide (AM), enhancing solubility and stability. Radical polymerization of AM forms a polyacrylamide (PAAM) network, which integrates with gelatin (Ge) and quaternized chitosan (QCS) to establish Ge-PAAM and QCS-PAAM networks. The presence of Ge and QCS introduces abundant hydrogen bonding sites, improving adhesion. Additionally, cellulose nanofibers (CNFs) and the conductive polymer poly(benzodifurandione) (PBFDO) create conductive pathways, boosting mechanical and electrical performance. This AM/Ge/QCS/CNFs/PBFDO-DES (AGQCP-DES) eutectic hydrogel exhibited high strength (184 kPa), remarkable stretchability (up to 5063 %), excellent self-adhesiveness (69.9 kPa). Additionally, the AGQCP-DES flexible sensor showcased impressive electromechanical performance, including high sensitivity (GF = 3.03), stable conductivity (0.47 S/m), rapid response times. This multi-network design paradigm not only overcomes classical hydrogel limitations but also provides a versatile platform for developing next-generation ionic hydrogel-based wearable devices.