North Carolina State University researchers have developed multiple 3D printing techniques that create free-standing structures with drops of liquid metal. One technique involves stacking droplets of liquid metal on top of each other, which adhere to one another, but retain their own shape.
Another technique injects liquid metal into a polymer template so it takes on a specific shape. The template is then dissolved, leaving the bare liquid metal in the desired shape. The researchers also developed techniques for creating stretchable liquid metal wires.
They are currently exploring how to further develop these techniques and how to use them in various electronics applications and in conjunction with established 3D printing technologies. Assistant Professor of Chemical and Biomolecular Engineering at NC State, Dr. Michael Dickey, said:
It’s difficult to create structures out of liquids, because liquids want to bead up. But we’ve found that a liquid metal alloy of gallium and indium reacts to the oxygen in the air at room temperature to form a ‘skin’ that allows the liquid metal structures to retain their shapes.