Engineered Stretchability of Conformal Parylene Thin-film On-skin Electronics

Abstract

Skin-compatible electronics have evolved to achieve both conformality and stretchability for stable contact with deformable biologicalskin. While existing research has largely concentrated on alternative materials, the potential of Parylene-based thin-film electrodesfor stretchable on-skin applications remains relatively untapped. This study proposes an engineering strategy to achievestretchability using the Parylene thin-film electrode. Unlike the conventional Parylene thin-film electrode, we introduce morphologicaladaptability via controlled microscale slits in the Parylene electrode structure. The slits-containing device enables unprecedented stretchabilitywhile maintaining critical electrical insulation properties during mechanical deformation. Finally, the demonstration on humanskin shows the mechanical adaptability of these Parylene-based bioelectrodes while their electrical characteristics remain stable duringvarious stretching conditions. Owing to the ultra-thinness of the Parylene coating, the wearable bioelectrode not only achieves stretchabilitybut also conforms to the skin. Our findings broaden the practical use of Parylene thin-film bioelectrodes.