Scientists create robot that can alternate between solid and liquid states
"John Connor?"By Rob Thubron
Forward-looking: Following the creation of robots that can alter their state between solid and liquid, humanity is once again left wondering if scientists have even watched Terminator 2. Researchers demonstrated one of the machines turning into ooze to escape the bars of a cage, not unlike the T-1000 in the 1991 classic.
This isn't a step toward creating a perfect killing machine, of course. A paper published in scientific journal Matter reveals that these magnetoactive phase transitional matter (MPTM) robots are designed for much more practical, non-sinister uses, such as entering a stomach as a small solid block, liquifying around a solid foreign object, reforming to capture it, then exiting the body.
The robots can also replace missing screws inside complex machines by entering a device, melting into a threaded screw socket, then reforming. The researchers also got the robots to solder circuits and overcome obstacle courses.
The robots were created by a team from The Chinese University of Hong Kong, led by engineer Chengfeng Pan. They're made from magnetic neodymium-iron-boron microparticles embedded in gallium, which melts at 29.8 degrees centigrade—close to room temperature.
In its solid form, the material can support objects up to 30 times its mass. Melting it requires the material to be placed near magnets with customized magnetic fields, which move the tiny magnetic pieces inside the robot, meaning no external heat source is needed.
Another example the team demonstrated was the robots carrying a lightbulb onto a circuit board before melting over its edges, allowing electricity to pass through their bodies and light the bulb. Researchers have also made them climb walls, leap over moats, and "split in half to cooperatively move other objects around before coalescing back together."
"Folks have been working on these small-scale, magnetically responsive robots and machines for quite a while now," Carmel Majidi, who heads the Soft Machines Lab at Carnegie Mellon University and is senior author on the new study, told Motherboard. "In parallel with that, my group has been pioneering a lot of techniques using liquid metals—metals like gallium that have a very low melting point."
As for the T-1000 tribute video, that's more of a playful nod to the shapeshifting Terminator that inspired the robot. The tiny Lego figure in the clip does melt from a solid into a liquid to escape its cage, but it is manually remolded into its original shape once through the bars. Still, it's very cool, if mildly concerning, science in action.