Printable, Stretchable Metal-vapor-desorption Layers for High-fidelity Patterning in Soft, Freeform Electronics

High-fidelity patterning of thin metal films on arbitrary soft substrates promises integrated circuits and devices that can significantly augment the morphological functionalities of freeform electronics. However, existing patterning methods that decisively rely on prefabricated rigid masks are severely incompatible with myriad surfaces. Here, we report printable, stretchable metal-vapor-desorption layers (s-MVDLs) that can enable high-fidelity patterning of thin metal films on freeform polymeric surfaces. The printed rubbery matrix with highly mobile chains effectively repels various metal vapors from the surface and inhibits their condensation, thereby allowing selective metal deposition. The s-MVDLs are printed by direct ink writing techniques, enabling customizable and scalable thin metal patterns ranging from the micrometer to millimeter scale with high fidelity. Furthermore, the superior stretchability and mechanical robustness of the s-MVDLs allow highly compliant deformation along the substrates, enabling the construction of unconventional circuits and devices on multi-curvature, non-developable, and stretchable surfaces.