Pressure-Induced Drift Artifacts in Stretchable Liquid Metal ThinFilm Electrocardiogram Electrodes

Reliably monitoring epidermal electrophysiological signals with precision is essential for advanced healthcare systems and next-generation human-machine interfaces. Although stretchable thin-film electrodes have shown promise for accurate electrocardiogram signal acquisition, the issue of pressure-induced drift artifacts remains largely overlooked. We developed a stretchable LM thin-film electrode integrated with an LM strain sensor to quantitatively investigate the drift artifact alongside skin deformation simultaneously and in situ. While most existing research focuses on strain-induced drift, our findings reveal that the pressure-induced drift artifact is more significant in stretchable LM electrodes. This work further emphasizes the limitations of the skin-electrode impedance model in explaining the pressure-induced drift, and confirms that its primary origin lies in skin potential change. Based on this, we validated an adaptive filtering method using the noise signal reconstructed from strain sensor data to calibrate pressure-induced drifts. Compared to traditional static filtering methods, it demonstrates superior performance in suppressing irregular pressure-induced drift artifacts.