Application of Flexible Skin Electrodes Based on Graphene-PEDOT:PSS/Parylene Composite Films in Gesture Recognition

Surface electromyography (sEMG) electrodes serve as the crucial "bridge" connecting human muscle activity with external analysis systems. To overcome the limitations of traditional Ag/AgCl gel electrodes, such as gel drying easily, skin irritation, and insufficient mechanical compliance, in long-term wearable surface electromyography monitoring, this study has developed a high-performance flexible dry electrode based on the graphene-PEDOT:PSS/polyarylene (Graphene-PEDOT:PSS/Parylene, GPP) composite system. By introducing sodium dodecyl sulfate and lithium difluoromethanesulfonimide to optimize the conductivity of PEDOT:PSS and the interface compatibility with graphene, and utilizing the π-π stacking interaction between graphene and PEDOT:PSS to construct a three-dimensional conductive network, a GPP film electrode with excellent flexibility, high conductivity (with a surface resistance as low as 2.62 Ω/sq), and good mechanical stability was successfully prepared. This electrode exhibited stable electrical performance during dynamic bending and repeated adhesion-deposition tests, and the electrode-skin interface impedance was only 8.8±0.7 kΩ at 100 Hz, significantly lower than that of commercial Ag/AgCl electrodes (25.1±1.6 kΩ). In sEMG signal acquisition, the GPP electrode showed a signal-to-noise ratio of up to 26.47 dB, far superior to that of Ag/AgCl electrodes (11.98 dB). Further, by preprocessing the sEMG signals based on gesture actions and inputting them into a one-dimensional convolutional neural network model, an average recognition accuracy of up to 95.83% for six gestures was achieved. This study provides an effective material strategy and technical solution for developing flexible wearable electronic devices suitable for long-term, high-precision biological signal monitoring, and has broad application prospects in rehabilitation medicine, human-computer interaction, and intelligent motion monitoring.