Wearable multilead ECG sensing systems using on-skin stretchable and breathable dry adhesives

Electrocardiogram (ECG) monitoring is used to diagnose cardiovascular diseases, for which wearable electronics have attracted much attention due to their lightweight, comfort, and long-term use. This study developed a wearable multilead ECG sensing system with on-skin stretchable and conductive silver (Ag)-coated fiber/silicone (AgCF-S) dry adhesives. Tangential and normal adhesion to pigskin (0.43 and 0.20 N/cm², respectively) was optimized by the active control of fiber density and mixing ratio, resulting in close contact in the electrode–skin interface. The breathable AgCF-S dry electrode was nonallergenic after continuous fit for 24 h and can be reused/cleaned (>100 times) without loss of adhesion. The AgCF encapsulated inside silicone elastomers was overlapped to construct a dynamic network under repeated stretching (10% strain) and bending (90°) deformations, enabling small intrinsic impedance (0.3 Ω, 0.1 Hz) and contact impedance variation (0.7 kΩ) in high-frequency vibration (70 Hz). All hard/soft modules of the multilead ECG system were integrated into lightweight clothing and equipped with wireless transmission for signal visualization. By synchronous acquisition of I–III, aVR, aVL, aVF, and V4 lead data, the multilead ECG sensing system was suitable for various scenarios, such as exercise, rest, and sleep, with extremely high signal-to-noise ratios.