Scientists have created a tiny robotic system that can go from solid to liquid and back again, bringing a bit of classic sci-fi lore to life while they’re at it.
It’s been 30 years since killer liquid metal robots entered our nightmares courtesy of 1991’s Terminator 2: Judgment Day. That movie’s shape-shifting T-1000 robot can overcome any obstacle while turning into a weapon at will.
The specter of Skynet and robot apocalypse has haunted us ever since, and now an international team of researchers has finally given us a real-world version of the T-1000, albeit with a more altruistic goal.
The team said it was inspired by Hollywood, but by the humble sea cucumber, which can transition between soft and rigid body states.
“Giving robots the ability to switch between liquid and solid states gives them more functionality,” said Chengfeng breadAn engineer from the Chinese University of Hong Kong who Led the research.
In a nod to Terminator-inspired night terrors, Pan and colleagues demonstrated this enhanced functionality by placing one of their tiny robots in a simulated prison cell and showing how it could escape.
It might be a little hard to see what’s going on in the video above, but basically the robot melts into the liquid, flows between the bars, and goes into a waiting mold where it cools, reforms itself, and then returns. Granted, this escapement is a bit less terrifying than the T-1000 because it needs a mold to rebuild itself, but it’s still enough to excite any Luddite.
A part of the demonstration Research published Journal of Wednesday Matters.
Carnegie Mellon University senior author Carmel Majidi says that magnets make all these future phase transitions possible.
“The magnetic particles have two roles here… one is they make the material responsive to an alternating magnetic field, so you can heat the material by induction and cause a phase change. But the magnetic particles also give the robot mobility and the ability to move in response to the magnetic field.”
The particles are embedded in gallium, a metal with a very low melting point of only 86 degrees Fahrenheit (about 30 Celsius), creating a material that flows more like water than other phase-change materials, which are more viscous.
In tests, the mini robots were able to climb obstacles, scale walls, split in half and reassemble while being magnetically controlled.
“Now, we’re pushing this material system in a more practical way to solve some very specific medical and engineering problems,” Pan said.
In other demonstrations, robots were used to solder circuits, deliver drugs and clean a foreign object from a model’s stomach.
The researchers envision the system being able to repair hard-to-reach spaces and act as a “universal screw” that melts into a screw socket and tightens without the need for actual screwing.
The team is particularly excited about potential medical uses.
“Future work should further explore how these robots can be used in a biomedical context,” Majidi said. “What we’re showing is just a one-off demonstration, a proof of concept, but much more research will be needed to find out how it could actually be used for drug delivery or foreign object removal.”
Hopefully the list of foreign objects that need to be removed never includes weaponized miniature melting robots, as they can be difficult to track and extract.