In the 1991 movie Terminator 2, the Terrible T1000 robot appears, it had a solid appearance, but it could liquefy to take various forms or go through a fence, turn its hands into weapons, lose part of its body, receive bullet impacts among other things, in the video shows a mini robot capable of doing something very similar, it can liquefy, escape from its cell and regain its shape.
In addition to changing quickly and reversibly from a liquid to a solid state, thanks to the new materials, these experimental robots are magnetic and can conduct electricity, it is also relatively strong, in another video we can see how the robot, this time in the form of a pill, moves through a stomach model and catches a ball.
The robot is the work of Chinese and American engineers who created it thanks to a new Phase Change material called the Solid Liquid Phase Transition Active Magneto machine, for this they basically managed to embed magnetic particles in gallium, gallium is a metal with a dot very low melting temperature of 29.8 degrees Celsius.
It is not a T1000, but it could be the granddaddy of future robots capable of liquefying to work in very special places, including inside the human body, to cure certain pathologies or extract foreign bodies from the human body.