It appears as though researchers at NC State have taken 3D printing a whole new level. A team has developed a way to print free-standing 3D structures out of liquid metal--at room temperature.
“It’s difficult to create structures out of liquids, because liquids want to bead up,” said Dr. Michael Dickey, co-author of a paper describing the technology and process. “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.”
Here’s a video showing the 3D printing process in action. (We think the bit where they print antennae on a bug is the best part. Especially if you think they look more like antlers than antennae.)
A syringe needle doles out the material in droplets, which forms an oxide “skin” that stabilizes the structures being formed. Alternately, the syringe can produce a steady stream of material that forms a wire; with these two methods, researchers were also able to connect droplets with wires. A third method consists of injecting the liquid metal into a template, and then dissolving the template and leaving the metal shape intact.
Connecting two LEDs
The material is stretchable, and it conducts electricity; you can see in the video that it’s used to connect two LEDs, although the printing process is sped up in the video by 40-50x.