Scalable liquid metal thin line patterning for passive electronic components using soft lithography

Abstract

This paper presents a size-scalable and residue-free liquid metal patterning technique for all-soft passive electronic components using soft lithography and gallium-based liquid metal (EGaIn, Eutectic Gallium-Indium Alloy). Using the proposed technique, uniform and smooth EGaIn lines with widths ranging from single micrometers to several millimeters are patterned on a PDMS mold at room temperature in ambient pressure. To highlight the process capabilities, the electrical characteristics of fabricated passive components, such as resistors, interdigitated capacitors, as well as vertical interconnects using flexible-through-PDMS vias (fTPVs) are investigated under bending and twisting deformation.