Ultrastable, Omnidirectionally Stretchable, and Transparent Electrodes Based on Ag@Au Core–Sheath Nanowires with Noncoplanar Patterns for Wearable Electronics

On-skin electrophysiological devices require stretchable transparent electrodes offering omnidirectional compliance, stable conductivity, environmental resilience, and high transparency. Herein, we present hierarchical, environmentally robust omnidirectionally stretchable transparent electrodes (OSTEs) using Ag@Au core-sheath nanowires (Ag@Au NWs). Fabrication employs reusable hydrophobic masks to pattern 2D geometries on prestrained substrates; strain release self-assembles 3D wrinkled architectures. Combined with salt-assisted NW cold-welding, this enables exceptional multidirectional stretchability and strain-tolerant conductivity. The optimized OSTE achieves 9.24 Ω/sq at 75.0% transmittance, withstands >10,000 cycles of 30% uniaxial strain (resistance increase <55%) across multiple orientations, and maintains resistance <1.5× initial under 100% equibiaxial strain. The conformal Au coating ensures thermal stability (250 °C) and environmental resilience (e.g., stable in 5 wt% H₂O₂). Ag@Au NW OSTEs deliver high-fidelity EMG/ECG signals with significant motion-artifact suppression during skin deformation and perspiration, outperforming commercial Ag/AgCl gel electrodes. This scalable materials-structure integration approach accelerates precise wearable biosensors for dynamic health monitoring.