Fast-Gelling, Adhesive, and Conductive Epidermal Electrode for Accurate Physiological Signal Monitoring and Real-Time Brain-Controlled Drone Flight

Conductive hydrogel electrodes are vital components for achieving human-machine interfaces. However, the inherent trade-off between high conductivity and favorable mechanical/adhesive properties remains a significant challenge for hydrogel-based epidermal electrodes. Here, we developed a multifunctional MXene/WPU/PAA (MWA) hydrogel electrode that combines robust mechanical properties, strong adhesion, and excellent conductivity. The introduced MXene nanosheets can induce free-radical polymerization, resulting in fast gelation (<5 min) at room temperature. Theoretical analyses reveal that MXene nanosheets form abundant hydrogen bonds with polymer chains, thus enhancing the cross-linking density and mechanical strength of the hydrogel electrode. The MWA hydrogel can form a stable skin-electrode interface, enabling high-fidelity multimodal physiological signal monitoring. Specifically, the signal-to-noise ratio (SNR) for sEMG reached 36.0 dB, while the SNR for ECG was 30.1 dB, outperforming the Ag/AgCl electrodes. The MWA hydrogel exhibits outstanding adhesion under repeated cycles and simulated sweat conditions, reaching 94.2 and 55.5 kPa, respectively. Furthermore, the MWA hydrogel electrode demonstrates precise scalp EEG monitoring, enabling wireless drone flight control via real-time brainwave decoding. This work provides insight into MXene-polymer interactions and demonstrates the applicability of the developed electrode to brain-computer interface applications.