First Liquid Machines Presage Soft Robots

KentuckyFC writes "The technology behind the T-1000 assassin in the Terminator movies might as well be science fiction as far as modern manufacturing is concerned. But we're making progress — thanks to some work by Chinese engineers who have perfected a way to make liquid metals assume various shapes and switch from one to another with the flick of a switch. These guys placed a thin film of gallium-indium-selenium alloy (melting point 10.5 degrees C) in water and applied an electric field. The balance between the surface tension of the metal and the electric forces on its surface then caused the metal to form a ball. They can move the sphere around, combine it with other spheres, and even use it to rotate the water. The engineers say this is the first step toward smart liquid machines that can assume almost any shape. And since the alloy is biologically benign, these machines could be used with, and even inside humans. Their next goal is to create a set of parallel electrodes that cause the metal to form into an undulating worm-shape that can propel itself along."