As reported in the technology blog of the New York Times Bits, scientists at North Carolina State University have engineered an alloy that remains in a liquid state in ambient temperatures. Consisting of gallium and indium, the alloy can be used in a 3-D printer. “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,” says Dr. Michael Dickey, assistant professor of chemical and biomolecular engineering at NC State and co-author of a paper describing the work in a press release. This effect makes it possible to extrude droplets of the material and create three-dimensional structures. The droplets adhere to one another, but retain their shape.
The alloy is conductive and therefore suitable for wires and electric components. The scientists describe their findings in the journal Advanced Materials. In their paper, “3-D Printing of Free Standing Liquid Metal Microstructures,” they describe the self-healing properties of the material. “These stretchable wires can be completely severed with scissors and [they] rapidly self-heal both mechanically and electrically,” the authors told Bits.
According to the press release, the research team is “currently exploring how to further develop these techniques, as well as how to use them in various electronics applications and in conjunction with established 3-D printing technologies.”
Video of the extrusion process: