Low-Cost Rapid Fabrication of Conformal Liquid-Metal Patterns

Patterned conformal conductive structures are used to realize flexible electronics for applications such as electronic skin, communication devices, and sensors. Thus, there is a demand for low-cost rapid fabrication techniques for flexible and stretchable conductors. Spray-coating of liquid metals is a prototyping method that is compatible with elastic substrates. In this work, UV-curable and polyimide masks were used to pattern sprayed liquid metal (LM). The effect of the spraying parameters on the thickness and conductivity of the LM was characterized. A minimum LM linewidth of 48 µm was achieved, along with a minimum gap width of 34 µm. A LM patch antenna and transmission line, which can potentially be used for communication systems, were demonstrated using this fabrication process.