Development of Grid-Structured Conductive Microfiber-Based Skin Electrodes for Facial Muscle Movement Detection

In this research, we fabricated semi-transparent skin electrodes based on grid-structured PEDOT:PSS microfibers and ion gel-permeated electrospun polyvinyl alcohol (PVA) nanofibers. Grid-structured PEDOT:PSS microfibers exhibit high optical transparency, decent electrical/electrochemical characteristics, mechanical flexibility, and modest stretchability owing to large empty spaces between highly crystalline PEDOT:PSS microfibers. To enhance their adhesion to and electrochemical interfacing with skin, a thin layer of electrospun polyvinhyl alcohol (PVA) nanofibers was employed after being permeated with ion gels. The resultant skin electrodes enable the long-term high-fidelity measurement of various biological signals such as electrocardiogram, electromyogram, electrooculogram with minimal skin irritation and aesthetic concerns. Finally, it was demonstrated that grid-structured PEDOT:PSS microfibers are capable of detecting facial muscle movements which can be potentially translated into non-verbal communications such as emotional expression.