Scientists make real-life Terminator T-1000 - a robot that can turn to liquid

Fans of The Terminator movies found themselves on the edge of their seats watching the unstoppable T-1000 robot in Terminator 2: Judgment Day.

Particularly thrilling was the way it could overcome any obstacle by turning to liquid and then reforming as a solid.

This feature is now a reality - as scientists from The Chinese University of Hong Kong have created a man-shaped robot that can do the same. It can 'escape' a jail by turning to liquid, slipping through the bars of its cell, and then reforming outside.

Inspired by sea cucumbers, the miniature robots rapidly and reversibly shift between liquid and solid states.

On top of being able to shape-shift, the robots are magnetic and can conduct electricity. Where traditional robots are hard-bodied and stiff, "soft" robots have the opposite problem; they are flexible but weak, and their movements are difficult to control.

"Giving robots the ability to switch between liquid and solid states endows them with more functionality," said Chengfeng Pan, an engineer at The Chinese University of Hong Kong, who led the study.

The team created the new phase-shifting material - dubbed a "magnetoactive solid-liquid phase transitional machine" - by embedding magnetic particles in gallium, a metal with a very low melting point.

"The magnetic particles here have two roles," explained senior author and mechanical engineer Carmel Majidi of Carnegie Mellon University. "One is that they make the material responsive to an alternating magnetic field, so you can, through induction, heat up the material and cause the phase change. But the magnetic particles also give the robots mobility and the ability to move in response to the magnetic field."

This is in contrast to existing phase-shifting materials that rely on heat guns, electrical currents, or other external heat sources to induce solid-to-liquid transformation.