At the North Carolina State University, Michael Dikey and his team used a mixture of gallium and indium alloy, a mixture which remains liquid at room temperature, but when it comes into contact with air, it develops a thin skin that is strong enough to hold the liquid’s shape. When 3D printed, the shapes can be stretched without reverting to blobs. 3D printing with liquid metal could be used for micro-circuits and wearable electronics.
Dr Dikey said: “It’s an additive manufacturing technique, so you’re basically directly printing the material in 3D space. The resulting structures are soft, and if you embed them in, say, rubber, for example, you can create structures that are deformable and stretchable.”
Jason Heikenfeld, who is a professor of electrical engineering at the University of Cincinnati said this work is potentially revolutionary. “Folks have tried to work with liquid metal for some time – some of us when we were younger would break up a thermometer and you’d see liquid metal – mercury – go all over the place. It was evidence that although these materials have a significant upside, in terms of what you can do with them, they are extremely challenging to work with.”
And now we are in an age where flexible electronics are starting to emerge, companies like LG, Samsung and Nokia are experimenting with all kinds of possibilities. This mixture that can be applied with additive manufacturing techniques might well be a big step towards realizing this.
Professor Heikenfeld said: “Stretchable is a whole other game because you’re now talking about wearable and conformable,”. He also mentioned that recent research addressed another important problem with liquid metals, toxicity. The gallium and indium alloy mix is safe, unlike mercury.
He added that the recent research also addressed another important issue of using liquid metals – toxicity. Unlike mercury, the gallium and indium alloy was safe, he said.
This mixture doesn’t come cheap though… According to New Scientist, it will be about a hundred times as expensive as 3d printed plastic.