Breathable, Biocompatible, Ultrathin Bilayer Epidermal Electrodes for Long-Term and Motion-Artifact-Resistant Monitoring ofHigh-Fidelity Electrophysiological Signals.

Long-term monitoring of electrophysiological signals is of great importance for continuous health monitoring, disease diagnosis, and intelligent human-machine interaction. However, developing a breathable and biocompatible skin-electrode interface with low interfacial impedance for long-term and motion-artifact-resistant epidermal monitoring remains a major challenge. To address this issue, we propose a bilayer design that enables functional decoupling via synergistic structural integration. An ultrathin bilayer epidermal electrode integrating an ultrathin poly(α-lipoic acid) (PLA) adhesive layer with a porous thermoplastic polyurethane (TPU)/AgNWs conductive fibrous network (T-AgNWs film) is fabricated via coelectrospinning and subsequent concentration-induced interfacial polymerization. The ultrathin biocompatible adhesive layer ensures stable interfacial adhesion and mechanical compliance without sacrificing the breathability and conductivity of the porous network. As a result, high-fidelity electrophysiological signals including electromyography, electrooculography, electroencephalography, and electrocardiography are acquired under dynamic conditions. Reliable muscle fatigue assessment and accurate gesture recognition are further achieved, demonstrating its potential for physiological monitoring. This work provides a new strategy for designing electrophysiological electrodes with stable, breathable, biocompatible, and low-impedance interfaces.