Three-dimensional MXene/carbon nanotube composite electrodes in flexible 64-channel arrays for noninvasive electromyography signal acquisition

Abstract

Non-invasive surface electromyography (sEMG) electrodes have vast potential in fields such as healthcare, human-computer interaction, and entertainment, providing diverse information related to electromyographic signals. Non-invasive sEMG electrodes reduce user risks but gather sEMG signals of lower quality compared to invasive ones. Currently, various advanced electrode materials have been developed for detecting physiological electrical signals, but the majority of them are single channel electrodes. Here, we report 64-channel three-dimensional (3D) Ti₃C₂ MXene/CNT composite electrodes fabricated using bonding-driven self-assembly technologies. These electrodes are characterized by low skin-electrode contact impedance and a high signal-to-noise ratio (SNR) for collection of EMG signals. These electrode arrays exhibit remarkable flexibility, conforming seamlessly to the skin’s curvature. Specifically, the skin-electrode contact impedance of 3D Ti₃C₂ MXene/CNT electrodes decreases by 10-fold compared to Ag/AgCl gel electrodes at a frequency of 100 Hz. Furthermore, when collecting sEMG signals from the arm, the prepared Ti₃C₂ MXene/CNT electrodes exhibit lower baseline noise and higher SNR compared to Ag/AgCl gel electrodes. Furthermore, Ti₃C₂ MXene/CNT electrodes can collect sEMG signals of different hand gestures, while maintaining a high SNR (∼25 dB). By combining machine learning, sEMG signals from different gestures can be identified with a recognition rate exceeding 90%. The exceptional performance and scalability of these 3D Ti₃C₂ MXene/CNT electrodes indicate a promising future for shaping electronic skin and wearable device technologies.