Evaluating electronic and structural properties of Au and Cu substituted AgCl electrode for application in surface electromyography

Abstract The material content of electrodes is very much important for improving the signal quality of surface electromyography (sEMG) in various environments, in particular, long-term monitoring. The electronic and structural properties of silver/silver chloride (Ag/AgCl), a popular biopotential electrode for sEMG recording, were studied under different conditions by X-ray absorption fine structure (XAFS) spectroscopy calculations. The effects of substitution of good-conducting elements (Cu and Au) on Ag coordination were tested at different temperatures as well as possible defect conditions. In the Au-substituted AgCl material, an extension of the Ag K-edge spectra was detected due to the rich quantum symmetry of Au valence level. Hence, it was determined that Au atoms bond with Cl atoms stronger than Ag atoms. Additionally, it was determined that Au atoms also changed the ionic properties of Ag atoms by losing Ag-Cl bonds.