A Terminator-style shape-shifting robot able to LIQUEFY and reform has been developed by engineers inspired by sea cucumbers. The team took the humble sea cucumber as their inspiration to design miniature robots that rapidly and reversibly shift between liquid and solid states.
As well as being able to shape-shift, the engineers said their robots are magnetic and can also conduct electricity. They put the robots through an obstacle course of mobility and shape-morphing tests in a study published in the journal Matter.
Team leader Doctor Chengfeng Pan explained that 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.
Dr. Pan, an Engineer at The Chinese University of Hong Kong, said: “Giving robots the ability to switch between liquid and solid states endows them with more functionality.”
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 of 85.6 °F.
Senior Author Professor Carmel Majidi, a mechanical engineer at Carnegie Mellon University, in Canada said: “The magnetic particles here have two roles: 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.” He explained that the process 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.
Professor Majidi said the new material also boasts an “extremely fluid” liquid phase compared to other phase-changing materials, whose “liquid” phases are considerably more viscous.
Before exploring potential applications, the team tested the material’s mobility and strength in a variety of scenarios. With the aid of a magnetic field, the robots jumped over moats, climbed walls, and even split in half to cooperatively move other objects around before coalescing back together.
In one video, a robot shaped like a person liquefies to ooze through a grid after which it is extracted and remolded back into its original shape.
Dr. Pan said: “Now, we’re pushing this material system in more practical ways to solve some very specific medical and engineering problems.” The team also used the robots to remove a foreign object from a model stomach and to deliver drugs on-demand into the same stomach.
They also demonstrated how the material could work as smart soldering robots for wireless circuit assembly and repair and as a universal mechanical “screw” for assembling parts in hard-to-reach spaces.
“Future work should further explore how these robots could be used within a biomedical context,” Professor Majidi added.
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