Mussel-Like Silk Fibroin Hydrogel With Skin Compliance Soft Electrode for Wearable Devices

Flexible wearable electronic devices, capable of real-time physiological monitoring for personalized health management, are increasingly recognized for their convenience, comfort, and customization potential. Despite advancements, challenges persist for soft electrodes due to the skin's complex surface, biocompatibility demands, and modulus mismatch. In response, a mussel-inspired polydopamine-nanoclay-silk fibroin hydrogel (DA-C-SFH) is introduced, synthesized via a two-step process. The initial polydopamine oxidation introduces free catechol groups through polydopamine-incorporated nanoclay, followed by integration with silk fibroin, refining the fibroin network at the mesoscopic scale. This DA-C-SFH exhibits low modulus, high elasticity, adhesive properties, and biocompatibility, enabling conformal skin adhesion. It effectively detects subtle signals, such as pulse waves, and serves as a soft epidermal electrode, capable of recording various electrophysiological signals, including electrocardiograms and electromyograms, thus underscoring its potential in medical electronics and health monitoring applications.