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.