Wearable carbon nanotubes-based polymer electrodes for ambulatory electrocardiographic measurements

A simplified method is presented to fabricate polymer composite electrodes for electrocardiograph (ECG) measurements. The composite electrode was fabricated by loading a high content of carbon nanotubes (CNTs) and silver nanoparticles (Ag NPs) in polydimethylsiloxane (PDMS). The conductive polymer mixture was prepared by ultrasonically stirring and heat-stirring. Polymer electrodes were fabricated by the doctor blade technique. Two-dimensional electrodes were fabricated to evaluate the effect of thickness on signal quality. Three polymer electrodes were combined into the ECG electrode patch. The polymer electrodes were successfully applied in ECG measurements. Continuous measurements for 14 days indicated the polymer electrodes are suitable for long-term monitoring. Wearable electrodes were fabricated with a layer of gauze embedded by the CNT/Ag-PDMS mixtures. Conductive wires were sewed in the gauze as connectors for the measurement circuit. Three wearable electrodes were sewed into a vest as a measurement module. The ECG measurement results demonstrated that the wearable electrodes are qualified for such medical devices. The CNT-based polymer electrodes are flexible, washable, and suitable for long-term wear, possessing great promise in practical applications in wearable medical instruments.