Changes in Signal Morphology of 3D Printed Dry electrodes for Enhanced ECG Signal Quality in Dynamic Conditions

Traditional gel-based electrodes are widely used for bioelectric signal acquisition, but they come with drawbacks such as skin irritation, signal degradation over time, and the need for frequent replacements, making them less ideal for long-term health monitoring scenarios. This study explores the development of 3D-printed dry electrodes as a gel-free, reusable alternative for ECG monitoring. Gel-less electrodes of six distinct electrode geometries namely flat, dome, flat needle, curved needle, half pointed, and Pointed were fabricated using fused deposition modeling (FDM) with conductive polylactic acid (PLA) to evaluate the impact of shape on signal quality. ECG data collected in both resting and exercise conditions was evaluated by measuring the electrodes' electrical conductivity and analyzing key parameters, including kurtosis, skewness, signal-to-noise ratio (SNR), and standard deviation of Normal-to-Normal Intervals (SDNN), to compare their performance against conventional gel-based electrodes. The results demonstrate that 3D-printed dry electrodes can provide high-quality signals comparable to conventional electrodes in wild scenarios. Among the tested designs, the flat and FN electrodes exhibited the best performance making them particularly effective under both static and dynamic conditions. Future work will focus on enhancing flexibility, stretchability, and adhesion to improve comfort and long-term usability, making them more suitable for continuous, real-time monitoring in wearable healthcare applications.