Soon it will no longer be just the stuff of science fiction: morphing metal could pave the way for futuristic-sounding vehicles and robots, according to new findings.
Researchers from Cornell University think they are close enough to a future of robots and machines that can change shape for an entirely different mission – say, an aircraft that can alter the shape of its wings in midflight and then head straight into the ocean before it morphs into and acts like a submarine.
The key for Rob Shepherd, an engineering professor from Cornell University, and his team is a hybrid material that combines stiff metal with soft yet porous rubber foam. This offers both stiffness and elasticity, as well as a self-healing ability in order to recover from damage.
And it’s not far off from that shape-changing robotic assassin in “Terminator 2.”
“It’s sort of like us [humans] – we have a skeleton, plus soft muscles and skin. Unfortunately, that skeleton limits our ability to change shape – unlike an octopus, which does not have a skeleton,” explains Shepherd.
Instead the idea marries the rigid quality, load-bearing ability of humans with octopus-like creatures’ capacity for changing shape.
The hybrid material is a combination of Field’s metal, a soft alloy that has a low melting point and is lead-free, with a porous silicone foam. The goal is to produce something likely biocompatible.
According to the researchers, the elastomers foam is first dipped into the molten metal before being put inside a vacuum such that the alloy replaces the air found in the foam pores. The foam’s pore sizes are around 2 millimeters, something that could be adjusted to make a more flexible or stiffer object.
The material could be deformed when heated with more than 144 degrees, become rigid again when cooled, and return to its original ability and shape with reheating.
And what role would this material play? A morphing wing, which offers a micro air vehicle chance to transform instantly into an underwater vessel. The material could sweep or fold back and proceed underwater, unlike broad wings that break off whenever they hit the water.
Graduate student Ilse Van Meerbeek also envisioned this material to be integrated in search-and-rescue robots, which can negotiate their way through tight spaces and dangerous settings.
Softness is key here because you don’t want a rigid robot that can’t morph its shape well, reminded Shepherd, whose team also worked on so-called electroluminescent skin as another feature of soft robotics.
The findings were discussed in the journal Advanced Materials.
