Thumb-Sized Liquid Metal System for Robust Dynamic Electrocardiography Monitoring Against Motion Artifacts
Dynamic electrocardiography (ECG) monitoring during physical activity remains compromised by motion artifacts that corrupt signal fidelity, particularly with conventional gel electrodes whose impedance rises sharply under deformation. This work presents a thumb-sized liquid metal system integrating gallium-based epidermal electrodes with a self-adhesive elastomeric matrix to sustain robust ECG acquisition against motion. The electrodes exploit the fluidic compliance of eutectic gallium–indium to maintain continuous skin contact, while the adhesive formulation ensures stable interfacial coupling without additional fixation. The system achieves low motion artifact levels, preserving waveform morphology and R-peak detectability during ambulation. The compact form factor enables unobtrusive wearability, and the materials architecture addresses the trade-off between adhesion and conformability that limits existing dry electrodes. The study establishes a materials and device pathway for clinical-grade dynamic ECG in ambulatory and point-of-care settings, with implications for continuous cardiac monitoring where patient movement is unavoidable.