Ionic liquid regenerated cellulose membrane electroless plated by silver layer for ECG signal monitoring

Abstract

Flexible electrodes have attracted the interest of a wide range of people because they can monitor human health signals like ECG, EMG and EEG as wearable devices. However, PDMS-based membrane electrodes have the problem of di culty in depositing metal layers, while fabric electrodes have high contact impedance. Furthermore, the widely used Ag/AgCl electrodes have the shortcomings of skin in ammation or skin irritation. Therefore, we fabricate a skin-like electrical conductive electrode via electroless silver plating on the surface of regenerated cellulose membrane, in which the cellulose membrane is obtained by the dissolution of cotton ber with green solvent ionic liquid [Bmim]Cl. The asprepared biocompatible electrode with low skin-electrode contact impedance can be used as a dry electrode for a long-term period of use. The impedance at 700 Hz is only 8 kΩ/cm 2 , and the conductivity can reach 252 s/cm. After 5 hours of wear, the skin contact impedance of the electrode was only 10 kΩ/cm 2 under 700 Hz(when AgNO3 was used at a concentration of 0.20 mol/L). Importantly, the electrodes not only provide a stable and clear ECG signal, but also offer a high level of comfort and low impedance, when used for long-term health monitoring.