A new technique allows 3D printers to produce objects using liquid metal that, when dried, will remain flexible. The approach — which was devised by researchers at North Carolina State University — uses gallium and indium, two alloys that are non-toxic and remain liquid at room temperature. When exposed to air, however, a hardened skin forms on the outside of the alloys while the insides remain liquified, which results in bendable products.

NC State's Dickey Group — a research group inside of the school's Chemical and Biomolecular Engineering Department — has produced a report on its research, and a YouTube video that demonstrates their approach in action using both a syringe and 3D printers. Printing in metal isn't new, but producing flexible devices using liquid metal is unprecedented, and the Dickey Group believes it can eventually print wires surrounded by liquid metal as well. Such a move could open the door to a new range of 3D-printed, flexible electronics and bendable display components.

In an interview with New Scientist, lead researcher Michael Dickey said that the group envisions combining liquid metal with other materials "like rubber to make structures that you can stretch and deform." The one clear downside in all this so far is cost. According to Dickey, printing in liquid metal is currently about a hundred times more expensive than plastic.