Air-gap-free epidermal bioelectronics via ethanol-triggered interfacial reconstruction for high-quality electrophysiological monitoring

Stable and high-fidelity electrophysiological monitoring with dry epidermal electrodes remains limited by interfacial air gaps and mechanical mismatch, which induce dynamic impedance fluctuations and severe motion artifacts during skin deformation. Here, we introduce an ethanol-triggered interfacial reconstruction strategy that directly fabricates a ~ 5 µm-thick conductive nanomesh onto the epidermis, seamlessly conforming to complex skin micro-textures. This interfacial reconstruction effectively eliminates trapped air gaps, reduces mechanical mismatch, and establishes a stable low-impedance bioelectronic interface (37.8 kΩ at 100 Hz). Thus, it enables high-quality electrophysiological recordings with higher signal-to-noise ratio compared to commercial gel electrodes. The resulting nanomesh electrode exhibits high breathability and conformality, robust resistance to sweat, and on-demand ethanol-assisted removability. Hence, it allows long-term, irritation-free monitoring of electrophysiological signals under dynamic deformation and wet conditions. This thin epidermal electrode provides a new pathway toward reliable acquisition of electrophysiological signals, offering broad potential for personalized health monitoring, early disease diagnosis, and next-generation brain-computer interfaces.