Researchers at North Carolina State have demonstrated a method for using a 3D printer to create free-standing liquid metal structures at room temperature, which retain their shape via a "passivating oxide skin" that forms on the surface of the liquid metal when exposed to air.
Michael Dickey of the Department of Chemical and Biomolecular Engineering at North Carolina State University in Raleigh told New Scientist that the process could eventually be used to add metal wiring to plastic objects fashioned by standard 3D printing, which layers molten polymers that quickly cool to create non-conductive structures.
Dickey and his colleagues published their findings in the latest issue of the Advanced Materials journal.
In the video above, the researchers demonstrate the creation of bubble-like structures out of an alloy of the metals gallium and indium, as well as the use of a pressurised air pulse in a 3D printing nozzle to shoot out and detach a metal wire.
Dickey suggested that wrapping those wires in a flexible material could have useful applications, such as the creation of "bendy electronics."
"The fact that they are liquid means you could surround them with another material like rubber to make metallic structures that you can stretch and deform," he told New Scientist.
The researchers said equipping a standard 3D printer for liquid metal production would be as simple as switching out the nozzle for a syringe-like part. The non-toxic alloy used in their experiments could be added "a functional ink that you use with a 3D printer," Dickey said.
But New Scientist noted that for now, such a leap forward in 3D printing will be pretty costly — the North Carolina State team's liquid metal alloy is about 100 times more expensive than plastics currently used in 3D printing.