Liquid metal may look like nothing more than a small ball of metal, but it will have shape-shifting and self-propulsion abilities.
The device is made from a drop of metal alloy consisting mostly of gallium, which is a liquid at just under 30 degrees Celsius. Last year they discovered that an applied electrical current causes the gallium alloy to drastically alter its shape. Changing the voltage applied to the metal allowed it to 'shape-shift' into different formations. When the current was switched off, the metal returned to its original drop shape.
The machine has two processes. One is to create gases like hydrogen. Part of these gases form the propulsion. There's also something important, in fact very important, which is the electricity generated behind the alloy. So this galvanic battery creates an internal electrical power, and this type of electricity will very easily lead to stretching of the surface of the liquid metal in an asymmetrical pattern, and this pattern leads to rotations inside the liquid metal, and the process of these rotations will set the liquid metal in motion in a certain direction.