Strain-Insensitive Hydrogel Fiber Electrodes With Micropillar Arrays for Dynamic ECG Monitoring

Dynamic electrocardiographic (ECG) monitoring has become an indispensable tool in clinical diagnosis and non-invasive monitoring. However, its front-end sensing component, ECG electrodes, still have issues such as long-term stability and dynamic artifacts, which limit its application in high-reliability scenarios. Therefore, developing highly biocompatible ECG electrodes, reducing or stabilizing contact impedance, and eliminating relative sliding during movement are of utmost importance. Here, a textile-array electrode (TAE) was integrated with a micropillar array on the semi-interpenetrating network (SIN) textile, which was woven from core-sheath hydrogel fibers. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) was used as a conductive material to minimize electrolyte content and ensure high biocompatibility after continuous monitoring (24 h). Micropillar arrays with a larger contact area than Holter electrodes were applied to reduce contact impedance by 85%. Polyester filaments were served as the core layer and woven with cotton to stabilize electron density and resistance, achieving strain-insensitive characteristics (∼0.02%). TAE was embedded into the garment to capture precise ECG signals with a signal-to-noise ratio of 21.56 dB (similar to resting state) during dynamic monitoring, and these signals can be used to analyze RR intervals for heart rate variability. This work is conducive to more efficient, precise, and personalized health management solutions and promotes the development of intelligent medical technology.