Water-Removable Paste Electrode for Electrophysiological Monitoring on Hairy Skin

Various flexible electrodes have been developed to fulfill the requirements of electrophysiological monitoring. A key feature of these electrodes is their conformal and seamless contact with tissues or skins. Such contact is usually difficult to achieve when detecting electrophysiological signals from hairy skins, e.g., electroencephalogram (EEG) from the head without shaving hairs or noninvasive detection of animal signals. Herein, to address this problem, a composite paste electrode is developed by mixing a polymer matrix with conductive nanofillers. The paste electrode can conformally coat smooth or rough surfaces with adequate adhesion and function to collect electrophysiological signals. It records signals with signal-to-noise ratios comparable to those of commercial patch electrodes. With the paste electrode, direct detection of electrocardiogram (ECG) from rabbit skin is realized, which is usually conducted with invasive needle electrodes. High-quality EEG can also be collected from areas with dense hair, simplifying their detection. This composite provides convenient and comfortable electrodes for applications of electrophysiological monitoring on rough and hairy surfaces.