Breathable fabric-based hydrogel as wearable electrodes for long-term ECG monitoring

Hydrogel-based electrodes have exhibited notable advantages in monitoring human cardiac health due to their high flexibility, excellent biocompatibility, and wear comfort. However, challenges persist in enhancing their self-adhesion, reusability, shape retention, breathability, and anti-drying properties. To address these issues, this study introduces a novel fabric-based hydrogel composite electrode, tailored for long-term electrocardiogram (ECG) monitoring, characterized by superior mechanical strength and breathability. Utilizing a needle-punch membrane design and a conductive hydrogel preparation technique, we successfully synthesized a composite electrode that integrates the mechanical robustness (tensile stress up to 58.8 MPa), high adhesion (maximum adhesive strength of 10.7 kPa), good biocompatibility (cell survival rate is greater than 90 % after 24 h of incubation), exceptional breathability (>95 g/m 2 /day), and water retention capabilities (10 days, with approximately 35 % water loss) of both fabric and hydrogel. Experimental results reveal that, in comparison to commercial electrodes, the fabric-based hydrogel electrode markedly decreases skin-electrode contact impedance (lower than commercial Ag/AgCl electrodes). ECG monitoring experiments conducted under various physiological conditions and a 48-h continuous ECG signal acquisition test (with significantly higher signal quality than commercial Ag/AgCl electrodes) confirms the electrode's high-fidelity electrophysiological monitoring performance, highlighting its considerable potential for application in wearable, long-term health monitoring systems.