Scientists at North Carolina State University, Raleigh, developed a 3D printing technology to create free-standing structures made out of liquid metal at room temperature. They discovered 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 structures to retain their shapes, they said.
The researchers also developed multiple techniques to create these structures, which can be used to connect electronic components in three dimensions. While it is relatively straightforward to pattern the metal all on the same level, the researchers’ liquid metal structures can also form shapes reaching up or down.
One technique involves stacking droplets of liquid metal on top of each other, so that the droplets adhere to one another, but retain their shape. Another technique injects liquid metal into a polymer template, so that the metal takes on a specific shape. The template is then dissolved, leaving the bare, liquid metal in the desired shape.
In addition, the scientists developed techniques to create liquid metal wires, which retain their shape even when held perpendicular to the substrate.
The research was published in Advanced Materials.
