Skin-Conformal DES Hydrogel Electrode with Antibacterial Activity for High-Fidelity sEMG and Strain Sensing in Rehabilitation

The aging society has increased the need for precise, real-time monitoring of muscle rehabilitation. This study aimed to develop a multifunctional flexible sensor to overcome the rigidity, skin irritation, and single functionality of conventional electrodes. The ionically conductive hydrogel-based flexible sensor was fabricated via in situ polymerization using a deep eutectic solvent (DES, choline chloride/acrylic acid) as the conductive medium within a chitosan network. The electrode exhibited low interfacial impedance for high-sensitivity surface electromyography (sEMG) acquisition alongside excellent antibacterial properties, biocompatibility, and real-time strain-sensing capability. This work provided a low-cost, integrated wearable platform with significant potential for the personalized assessment and optimization of muscle rehabilitation training.