One major criticism of 3D printers is that the main material used for printing is plastic. How many items do you have that are made of only plastic? Not many. On a commercial scale, the use of plastic in 3D printers probably won’t change for a while, but researchers are developing some fascinating new materials used as “ink” for 3D printers.

The latest example comes from North Carolina State University where researchers have developed techniques to make free-standing structures using liquid metal at room temperature.

“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,” said Dr. Michael Dickey, a professor at NC State University and co-author of a new paper on the process, in a statement.

The researchers plan to use the process to develop electronics applications, especially useful for bendable electronics, as New Scientist reports:

It should be easy to swap the syringe for the nozzle of a 3D printer, potentially letting you print plastic objects containing metal wiring with a single device. “You could include this as a functional ink that you use with a 3D printer,” says Dickey.

The only drawback? The cost of printing with liquid metal is about 100 times more than the plastic used in 3D printers.