A flexible semidry electrode for long-term, high-quality electrocardiogram monitoring

Electrocardiogram (ECG) can assist doctors in diagnosing many cardiovascular diseases. In order to collect high-quality ECG signals continuously for a long time, low impedance and long-term stability are two essential properties of well-performing ECG electrodes. In this work, we fabricated ECG semidry electrodes with very low impedance and high stability by metalizing the surface of poly (vinyl alcohol) (PVA) hydrogel with silver nanowires. The PVA hydrogel continuously slow-release electrolyte to infiltrate the stratum corneum while applied, decreasing the stratum corneum’s impedance and minimizing the attenuation of ECG signals. The electrodes can continuously acquire high-quality ECG signals (SNR > 30) within 24 h. Moreover, the signals can be collected during the movement. This semidry electrode can be mass-produced at a low cost, which is very promising for broad applications in scenarios requiring precise ECG monitoring over a long period of time.