Highly Adhesive and\nStretchable Epidermal Electrode\nfor Bimodal Recording Patch

Abstract

For numerous biological and human-machine applications,\nit is critical\nto have a stable electrophysiological interface to obtain reliable\nsignals. To achieve this, epidermal electrodes should possess conductivity,\nstretchability, and adhesiveness. However, limited types of materials\ncan simultaneously satisfy these requirements to provide satisfying\nrecording performance. Here, we present a dry electromyography (EMG)\nelectrode based on conductive polymers and tea polyphenol (CPT), which\noffers adhesiveness (0.51 N/cm), stretchability (157%), and low impedance\n(14 kΩ cm² at 100 Hz). The adhesiveness of the electrode\nis attributed to the interaction between catechol groups and hydroxyls\nin the polymer blend. This adhesive electrode ensures stable EMG recording\neven in the presence of vibrations and provides signals with a high\nsignal-to-noise ratio (>25 dB) for over 72 h. By integrating the\nCPT\nelectrode with a liquid metal strain sensor, we have developed a bimodal\nrehabilitation monitoring patch (BRMP) for sports injuries. The patch\nutilizes Kinesio Tape as a substrate, which serves to accelerate rehabilitation.\nIt also tackles the challenge of recording with knee braces by fitting\nsnugly between the brace and the skin, due to its thin and stretchable\ndesign. CPT electrodes not only enable BRMP to assist clinicians in\nformulating effective rehabilitation plans and offer patients a more\ncomfortable rehabilitation experience, but also hold promise for future\napplications in biological and human-machine interface domains.