Flexible and Washable Poly(3,4-ethylenedioxythiophene): Polystyrene Sulfonate/Polyvinyl Alcohol Fabric Dry Electrode for Long-Term Electroencephalography Signals Measurement

Recent advancements in smart textiles have facilitated their extensive application in wearable health monitoring, particularly in brain activity measurement. This study introduces a flexible and washable fabric dry electroencephalography (EEG) electrode designed for brain activity measurement. The fabric dry electrode is constructed from electrically conductive polyester fabric with a resistivity of 0.09 Ω·cm, achieved by applying a PEDOT: PSS/PVA conductive paste coating on the textile substrate. A comparative analysis of the tensile properties between the conductive and untreated polyester fabric was conducted. The SEM images demonstrated that the PEDOT: PSS/PVA conductive polymer composite resulted in a uniform coating on the fabric surface. When enveloped in elastic foam, the fabric dry electrode maintained a low and stable electrode-skin contact impedance during prolonged EEG monitoring. Additionally, the short circuit noise level of the fabric dry electrode exhibited superior performance compared to both Ag/AgCl wet and finger dry electrode. The EEG signals acquired from the fabric dry electrode were comparable to those recorded by the Ag/AgCl wet electrode. Moreover, the fabric electrode effectively captured clear and reliable EEG signals, even after undergoing 10 washing cycles. The fabric dry electrode indicates good sweat resistance and biocompatibility during prolonged monitoring.