Artificial Camouflage Can Mimic An Octopus
As some of us know, the octopus is a master of disguise. And interestingly enough, some scientists were able to create an artificial camouflage that mimics this. An octopus, for instance, can take cues from its surrounding environment, like a coral, or rock and become almost indistinguishable from it. These researchers from the Cornell University were able to design their own artificial camouflage which stretches and changes in 3D. This ‘skin’ is able to be programmed to change in all sorts of shapes.
The secret behind their ability to change shape is some small 3D bumps on the surface of their skin. These bumps, officially called papillae, can raise an retract in one-fifth of a second – changing the shape of the animal in the process. As most of us know, octopi don’t have any bones in their bodies, and as a result, they can fit in small spaces and crevices found on the ocean floor. Moreover, the can also change their appearance to better blend in with their surrounding.This trait of theirs developed as a means of defence. After all, it’s easier and less energy intensive to learn how to hide from your predators than to actually try and outrun them.
These Cornell scientists and engineers worked closely with cephalopod biologists in order to design their artificial camouflage. Firstly, these biologists explained what papillae are – which are basically muscular hydrostats. These can be further described as a biological structure that performs actions by making use of only muscles – with no bony frames to support it. To better understand what this means, think of your tongue since in too is one such muscular hydrostat.
“Lots of animals have papillae, but they can’t extend and retract them instantaneously as octopus and cuttlefish do,” says Hanlon, who is the leading expert on cephalopod dynamic camouflage. “These are soft-bodied molluscs without a shell; their primary defense is their morphing skin.”
“The degrees of freedom in the papillae system is really beautiful,” Hanlon said in a press release. “In the European cuttlefish, there are at least nine sets of papillae that are independently controlled by the brain. And each papilla goes from a flat, 2D surface through a continuum of shapes until it reaches its final shape, which can be conical or like trilobes or one of a dozen possible shapes. It depends on how the muscles in the hydrostat are arranged.”
After understanding how this biological process works, the engineers developed a synthetic tissue that can be programmed to extend and retract. An algorithm is then capable of determining how that pattern is set in that tissue fibre. After that is done, the silicone is simply inflated, in order to take on the desired shape.
“Theoretically, you could do this really, really quick — milliseconds,” says study coauthor James Pikul.