Quantitative Comparison of the Performance of Injection-Molded Polymeric Microneedle Dry Electrodes and Traditional Gel Electrodes for ECG Signal Acquisition

Wearable dry electrodes facilitate continuous long-term electrocardiogram (ECG) monitoring, which is beneficial for the early diagnosis and management of heart disease. However, existing dry electrode technologies face limitations in maintaining clinically acceptable signal quality during movement, restricting their usability when patients are active. This is particularly critical for cardiac patients—such as those with arrhythmias or heart failure—who benefit from continuous monitoring during daily activities, exercise, or rehabilitation, where motion artefacts often obscure clinically relevant ECG features. To address this gap, we present microneedle (MN) dry electrodes, manufactured using a cost-effective industrial injection moulding process that is scalable for mass. We performed a study on a small cohort of healthy volunteers, to compare the ECG signal quality recorded using MN dry electrodes with that obtained using conventional gel electrodes, under both static and ambulatory conditions. Signal quality was statistically assessed using parameters such as ECG waveform morphology, R-peak-to-peak interval, and heart rate variability (HRV) time-domain. The results demonstrate that MN dry electrodes exhibit signal quality comparable to that of wet electrodes, even under ambulatory motion. This finding highlights the novelty of a low-cost, mass-producible microneedle electrode technology that could bridge the gap between experimental dry electrodes and clinically accepted wet electrodes.