A Hydration‐Triggered Electronic Skin for Integrated Biomechanical and Non‐Invasive Plasmonic Biochemical Sensing

Wearable electronic skins capable of overcoming sweat interference and leveraging sweat biomarkers are crucial for clinical‐grade monitoring. Here, we report a holistic hydration‐triggered whole‐body E‐Skin (HTWB‐E‐Skin) constructed from a biocompatible composite of nanofibrous silk fibroin and silver nanowires (Ag NWs). The elegance of this design lies in its structurally simple, multifunctional architecture, which leverages the hydration‐triggered mechanism to synergistically enhance both biomechanical and biochemical sensing. On one hand, the design leverages silk's hydration‐triggered conformational transition, as confirmed by theoretical and experimental studies, to achieve rapid sweat absorption (<10 s), exceptional water retention (>600% mass increase), and stable adhesion on wet skin. On the other hand, the embedded Ag NWs with silk fibroin concurrently enable motion‐robust electrocardiogram (ECG) monitoring and generate plasmonic hotspots for surface‐enhanced Raman spectroscopy (SERS). Through passive capillary action, trace sweat is autonomously channeled to sensing zones, enabling label‐free, real‐time continuous metabolic dynamics analysis of clinically relevant biomarkers (e.g., uric acid and urea) at ultralow concentrations, facilitating personalized nutritional oversight and health management. Integrated with a portable 12‐lead Cloud‐ECG module, the platform supports motion‐adaptive ECG, speech recognition, and whole‐body motion sensing, outperforming commercial electrodes, offering a practical methodology for long‐term personalized health monitoring and point‐of‐care diagnostics.