Liquid Metal Printing for Manufacturing Large-Scale Flexible Electronic Circuits

The advancement of printed electronics technology has significantly facilitated the development of electronic engineering. However, so far there still remain big barriers to impede the currently available printing technologies from being extensively used. Many of the difficulties came from the factors like: complicated ink-configurations, high post-treatment temperature, poor conductivity in room temperature and extremely high cost and time consuming fabrication process. From an alternative strategy, our recently invented desktop liquid metal printer offered a flexible way to better address the above deficiencies. Through modifying the system developed in the authors’ lab, here we demonstrated the feasibility of the method in quickly and reliably printing out various large area electronic circuits. Particularly, the liquid metal ink made of GaIn_24.5 alloy, with a high electrical resistivity of 2.98×10⁻⁷ Ω·m, can be rapidly printed on polyvinyl chloride (PVC) substrate with maximum sizes spanning from centimeter size to meter large. Most important of all, all these manufactures were achieved at an extremely low cost level which clearly shows the ubiquitous value of the liquid metal printer. To evaluate the working performance of the present electronics fabrication method, the electrical resistance and wire width of the printed circuits were investigated under multiple overprinting cycles. For practical illustration purpose, LED lighting conductive patterns which can serve as a functional electronic decoration art were fabricated on the flexible plastic substrate. The present work sets up an example for directly making large-scale ending consumer electronics via a high-efficiency and low-cost way.