Biomass-based dual-network multifunctional hydrogel for durable wearable sensors and emergency hemostasis

Conductive hydrogels derived from natural biomass are considered ideal candidates for flexible electronics and biomedical applications. However, developing conductive hydrogels that simultaneously achieve high mechanical strength, strong adhesion, good conductivity, and excellent biocompatibility remains a significant challenge. Herein, a multifunctional dual-network hydrogel (PGO/ CO -CA) composed of a carboxymethyl cellulose-based dynamic crosslinking network and a polyacrylamide network is proposed. Inspired by mussel adhesive proteins, polydopamine-modified conductive graphene nanosheets were incorporated to endow catechol-like adhesion and enhance the conductivity (0.46 S/m) and sensitivity (gauge factor, GF = 2.26). Additionally, branched polyethyleneimine (PEI) was introduced to strengthen the hydrogel network through electrostatic interactions and to enhance durability across a wider sensing range. By adjusting the Schiff-base crosslinking ratio and the PEI content, the hydrogel exhibited tunable modulus (stress: 113.5 kPa; strain: 1672%), which matched skin tissue, making it suitable for real-time motion signal monitoring and Morse code transmission. The hydrogel exhibited strong tissue adhesion (13.7 kPa), enabling conformal attachment to the skin for accurate physiological signal detection (electrocardiogram and electromyographic) and machine-learning-based gesture recognition (accuracy: 98%). Furthermore, it formed a robust physical barrier on wound surfaces, achieving rapid and effective hemostasis. In summary, the multifunctional biomass hydrogel developed in this work holds great promise for applications in flexible sensing and emergency hemostasis.