A Highly Miniaturized, Stable, Breathable E-Skin Patch for Skin-Hydration and ECG Monitoring

In this work, we developed a highly miniaturized and breathable multifunctional electronic skin patch (e-skin) with ultra-stable performance incorporating strain-insensitive design strategies for continuous skin hydration and ECG monitoring. We applied vertically stack-architecture which enabled the integration of multiple sensors with the choice of flexible and strategical placement; overcoming sensor overcrowding and crosstalk interferences observed over single plane. A combination of conductive nanoporous carbon and carbon nanotube (N-CNT) ink was used to develop highly sensitive hydration (0.77 %/%⁻¹) and ECG electrodes (SNR 27.27 dB) for the first time with strain-insensitive designs. Unlike traditional e-skins, this patch employs a resilient, air-permeable elastomer substrate via a simple phase-separation technique, improving comfort and reliability.