Motion‐Robust Multichannel sEMG Array for High‐Fidelity Muscle Fatigue Monitoring

ABSTRACT Real‐time muscle fatigue monitoring during dynamic activities is critical for preventing injury and optimizing performance, yet remains hindered by motion‐induced signal artifacts in conventional wearable systems. Here, we present a motion‐robust, multichannel surface electromyography (sEMG) array that enables high‐fidelity neuromuscular signal acquisition and localized fatigue assessment during complex movements. The platform integrates a bacterial cellulose (BC)‐reinforced heterogeneous eutectogel (BHE) with a hollow‐patterned flexible printed circuit (FPC), wherein the BC network dissipates mechanical stress to preserve structural stability. This heterogeneous interface ensures seamless skin‐electrode contact and suppresses signal distortion under motion. The six‐channel FPC electrode configuration facilitates spatially resolved tracking of muscle synergy and fatigue progression. The system exhibits minimal resistance drift over 100 000 bending cycles and maintains impedance stability across a broad frequency range (1 to 10 5 Hz), achieving an average signal‐to‐noise ratio of 41 dB. In real‐world scenarios, the device captures sEMG variations across localized muscle regions with reduced motion artifacts, enabling differential fatigue analysis. Furthermore, the model achieved 83.1% accuracy across four fatigue states in an independent external cohort comprising 160 samples from 40 previously unseen participants. This work demonstrates a wearable platform for continuous muscle monitoring with potential applications in sports science and rehabilitation.