Self-Maintaining Electrode-Skin Interface for Motion-Robust Biosignal Monitoring.

The electrode-skin interface presents a fundamental challenge in bioelectronics: maintaining stable electrical contact with tissue that undergoes constant physiological changes. Here we demonstrate a paradigm shift by engineering a self-sustaining microenvironment at the skin-electrode interface through the integration of Au-coated fabric electrodes with a humidity-regulating cooling patch. Our smart electrode-integrated cooling (SEIC) patch uses evaporative cooling to create a humid microenvironment where water condensation continuously regenerates ionic pathways between skin and electrode. This transforms the interface from a static contact point to a dynamic, self-renewing electrochemical junction. The SEIC patch exhibits 200-fold and 10-fold lower impedances than Au-coated fabric electrodes and conventional electrodes, respectively; maintains performance through 2000 attachment cycles; enables stable biosignal acquisition for eight days; and preserves signal fidelity under motion. Moreover, the SEIC demonstrates applications in continuous cardiac monitoring during daily life, and real-time 3D facial animation reconstruction in virtual reality via high-fidelity capture of facial muscle activity. This work opens new frontiers in preventive medicine and human-computer interaction.