A Fast and Cost-Effective Transfer Printing of Liquid Metal Inks for Three-Dimensional Wiring in Flexible Electronics

The fluidity and high electrical conductivity of a liquid metal make it an excellent material for preparing flexible electronics. Here, we established a method utilizing a widespread laser-printing technique to manufacture 3D flexible electronics. Through digital constructing of liquid alloy-philic smooth toner on liquid alloy-phobic rough substrates, we have the liquid metal selectively adhered to the designed pattern. The liquid metal circuit can then be transferred to an uneven and deformable Ecoflex surface to form a 3D circuit. Computational fluid dynamics simulation was performed to interpret the printing mechanism of the liquid metal on a substrate with selected adhesion. Flexible electronics fabricated through this method reveal great performance and stability, opening up opportunities for office and home flexible electronics manufacture, especially for lighting, heating, and logistics. By making the full use of the laser printers, our method not only saves the cost and time in preparation but also identifies favorable prospects for the mature laser-printing industry to promote next-generation flexible electronics fabrication.