In the film Terminator 2, the evil robot from the future is made of a shape-shifting liquid metal that can survive getting hit with everything from shotgun shells to grenades. Building that kind of machine isn't possible yet, but Australian scientists have taken a small step in that direction: they've created a liquid metal droplet that doesn't splatter and retains its shape like a rubber ball.
The advance could lead to self-healing liquid metal circuits whose wires simply flow back together if cut or frayed. Other applications are also possible, such as soft electronics that can be molded into any shape, semiconducting circuits or even liquid ball bearings.
Liquid metal is used in a number of applications already, such as the mercury switches in thermostats and roll sensors. Mercury is pretty toxic, though, and isn't always a good fit for electronics.
Vijay Sivan, a research fellow at the Royal Melbourne Institute of Technology's School of Electrical and Computer Engineering, along with his colleagues, coated a drop of galinstan - a mixture of gallium, indium and tin - with nanometer-sized particles of materials such as Teflon and carbon nanotubes.