The effect of chlorine/argentum atomic ratios on electrochemical behaviors and signal acquisition abilities of embroidered electrodes for bio-potential signal measurement

Bio-potential dry electrode is an important part of smart garments or wearable devices for monitoring bio-potential signals. In this work, embroidered electrodes are developed by embroidering silver-plated yarns in woven fabric. Then, AgCl is electrochemically deposited on silver-plated yarns in the embroidered electrode, and the chlorine/argentum (Cl/Ag) atomic ratios can be adjusted by the chlorination time. Moreover, a novel active evaluation system of wearable bio-potential electrodes developed by our group is utilized to evaluate the performance of the embroidered electrodes, and two novel indexes (bio-potential phase shift and voltage amplitude attenuation) were presented for evaluating the performance of embroidered electrodes. Results show that the chlorination of silver-plated yarns can improve the performance of embroidered electrodes. The electrochemical behaviors and signal acquisition abilities of the embroidered electrodes can be affected by Cl/Ag atomic ratios. The embroidered electrodes with the Cl/Ag atomic ratios of 62% (E-90) have the lowest impedance (3364 +/- 894O), and their static open-circuit potential and dynamic open-circuit potential variation are all less than 7mV. During the standard ECG signal test, E-90 shows the minimum bio-potential phase shift (0.011s), voltage amplitude attenuation (11.768%), noise amplitude (0.025mV), and maximum signal to noise (41dB). The noise amplitude of human body ECG of E-90 is also the lowest (0.013mV) and signal to noise is the maximum (40.996dB). The embroidered electrodes have broad application prospects in long-term health-monitoring system.