If 3D printing is truly going to revolutionise how we produce everything from cars, to computers, to weapons, it's going to have to move past the current limitations of plastic as a printing material. And what better place to start than a next-generation 3D printer that extrudes liquid metal?
That's exactly what researchers at North Carolina State University have developed, and it could be the next big leap in 3D-printing technology.
Turning strands of plastic into a malleable goo that can be squeezed through a tiny print head doesn't require a heck of a lot of heat. Metal, on the other hand, requires giant foundries and furnaces to reshape and mould. So the researchers at NCSU, led by Michael Dickey, developed a special metal alloy that's already in a liquid state at room temperature. Made from a mixture of 75 per cent eutectic gallium alloy and 25 per cent indium, when the material is exposed to air something neat happens: a thin outer layer of gallium oxide is formed, allowing the extrusion to hold its structure and shape.
In a way, you can think of the small beads and long cylinders this 3D printer creates as tiny water balloons, but filled with liquid metal instead of H20. And the thin gallium oxide outer layer is not only flexible — allowing the extrusions to be further moulded and shaped — it also conducts electricity so it can be used as wires or other components of electronics.
Maintaining a specific shape while printing with the unique metal is a tricky process that requires the exact amount of pressure so that the thin wires and shapes don't collapse, or explode. So using the new technology to print something like a T-1000, or even a simple paper clip, is still impractical. But it does have the potential to revolutionise how electronics are manufactured, and at the least, simplify the creation of prototypes. And it's another important step towards advancing 3D printers to the point where creating anything you want is a button press away.