A Bioinspired, Durable, and Nondisposable Transparent Graphene Skin Electrode for Electrophysiological Signal Detection

Graphene, with its properties of intrinsic flexibility, reliable electrical performance, and high chemical stability, is highly desirable as bioelectrodes for detecting electrophysiological signals. However, its mechanical properties limit its application to a great extent-energy dissipation mechanisms are not provided by the carbon network for external strain and it easily cracks. Herein, inspired by the very structure of the avian nest, we report a durable and nondisposable transparent graphene skin electrode for detecting electrophysiological signals, which was fabricated by semi-embedding highly graphitized electrospun fiber/monolayer graphene (GFG) into soft elastomer. Because of the semi-embedded structure and strong interaction between annealed electrospun fiber and graphene through graphitization, as-fabricated conductive film demonstrated high conductivity and transparency (similar to 150 Omega/square at 83% transmittance), as well as a stable electrical performance under mechanical vibrations (strain, peel-off, stir, etc.). It can be used to reliably collect vital biometric signals, such as electrocardiogram ( ECG), surface electromyogram (sEMG), and electroencephalogram (EEG). Furthermore, the semi-embedded GFG in the elastomer demonstrated excellent washability (rinsing/stirring in water) and repeatability (similar to 10 repeats) with high signal-to-noise ratio (up to 30 dB) while detecting sEMG. This is the first report of durable and transparent graphene skin electrode for biometric signals detection, revealing potential opportunities in wearable healthcare applications.