Most modern robots can only work in one mode, but scientists at Virginia Tech University (USA) have created machines that can change their shape to move on land, water or air. This was made possible thanks to a rubber shell filled with metal, which easily changes from a solid to a liquid state and vice versa.
The authors of the project borrowed the structure of the liquid metal robot’s shell from kirigami, the Japanese art of cutting figures out of paper and cardboard. The body is made of triangular elements, speckled with a network of tubes containing a metal alloy with a low melting point. In solid form, the alloy acts as an endoskeleton and allows the device to hold one form or another indefinitely. If necessary, the device can return to its original state. The heater and electric drives are responsible for the transformation. The melting point of the metal is as low as 60C, and the drive configuration allows the machine to change shape in less than 0.1 seconds.
During the testing of the system, the authors of the project built two robotic prototypes. The first liquid metal robot moves on a horizontal surface on wheels, but if necessary, changes shape and turns into a drone that rises into the air with propellers. The second liquid metal robot is designed to work in water, and its variable structure serves as an engine; the machine descends to the bottom of the aquarium, captures the objects (balls) located there and rises back to the surface.