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(Ag CF-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 Ag CF-S dry electrode was nonallergenic after continuous fit for 24 h and can be reused/cleaned(>100 times) without loss of adhesion. The Ag CF 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, a VR, a VL, a VF, 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.