It may not quite be a character out of the Terminator 2, but university scientists have developed a way to use 3D printing to create structures made out of liquid metal.
Researchers at North Carolina State University use 3D printing to stack droplets of liquid metal on top of each other, likening the effect to a stack of oranges at the grocery store. The droplets adhere to each other but retain their own shape instead of melding into one large droplet, the university reports.
While many people might be picturing Terminator 2's T-1000, a shapeshifting robot assassin made of liquid metal, university researchers have slightly different plans for the technology. Scientists are focused, at this point, on using their 3D printing techniques to build wires for building and connecting electronic components.
"It's difficult to create structures out of liquids, because liquids want to bead up," said Michael Dickey, an assistant professor of chemical and biomolecular engineering at North Carolina State, in a statement. "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."
Another technique that Dickey and his team created injects liquid metal into a polymer template. The metal takes on the shape of the template but then the template dissolves, leaving the bare metal.
Three-dimensional printing has been making great strides in recent months.
In June, researchers at Harvard University and the University of Illinois at Urbana-Champaign announced that they had used 3D printing to produce lithium-ion batteries the size of a grain of sand.
NASA scientists talked this spring about taking 3D printers into space to produce tools, and even food, for astronauts.
"As NASA ventures further into space, [whether] redirecting an asteroid or sending humans to Mars, we'll need transformative technology to reduce cargo weight and volume," NASA's chief administrator Charles Bolden said in May. "In the future, perhaps astronauts will be able to print the tools and components they need in space."
Some 3D technologies are even driving controversy. Lawmakers and the public took notice earlier this year when the organization Defense Distributed fired a handgun made with 3D printing technology, prompting the New York City Council to introduce legislation that would prohibit anyone other than those licensed as gunsmiths from using 3D printers to make guns and related equipment. The state of California Assembly also introduced a bill banning guns made using 3D printing.
Scientists at North Carolina State University use 3D printing to create structures made out of liquid metal.