Performance of PDMS-Based Inexpensive Stretchable Dry Electrodes in Long-Term sEMG Monitoring

Accurate and consistent monitoring of vital body signals is of particular importance for physiological studies and wearable health care applications. The rapid development of dry bio-potential electrodes has decreased the use of conventional wet electrodes. The development of flexible/stretchable bio-potential electrodes using non-toxic and bio-compatible materials is essential; considering the comfort of the user. Generally, fabricating such microelectrodes requires high-end facilities, which makes the final product relatively expensive. In this work, a bar-shaped dry stretchable sEMG electrode, including two input electrodes and a reference electrode (with the size of 10 mm × 4 mm) on a stretchable substrate, is designed. The micro-structured electrode composed of Au and Cu as the metal layer, polyimide (PI) as the flexible support layer, and PDMS as the main stretchable material is fabricated and used for EMG signal monitoring applications. The microelectrodes are highly conformable and follow curvilinear surfaces like the skin. The stretchable dry electrode performs comparatively similar to the conventional Ag/ AgCl electrodes, even in long-term scenarios.