A gray-green patch of coral appears to sway with the ocean current in a video that was captured by marine biologist Prof. Roger Hanlon, ecology and evolutionary biology, Brown University. Suddenly, part of the coral changes color, expands and darts away.
But what looks like coral isn’t coral — it is an octopus hiding from a predator using camouflage.
This camouflage behavior was the inspiration behind the development of a new technology by Cornell researchers. Prof. Itai Cohen, physics, its lead researcher, said that the project required the cooperation of multiple fields of science.
Cohen teamed up with soft robotics specialist Prof. Robert Shepherd, mechanical and aerospace engineering, and former Cornell post-doc James Pikul to design the technology. After working together for a year and a half, they created a “deformable surface” that can be manipulated to inflate into anything, from the irregular shapes of river stones to the form of a succulent plant.
The following video from the researchers’ study shows how flat surfaces can be designed to inflate into a three-dimensional topograph.
In this video, a surface was programmed to morph into the shape of a succulent:
This surface was programmed to look like different arrangements of pebbles:
Inspired by how octopi and other cephalopods — squids, cuttlefish and nautilus — camouflage, these researchers sought to emulate how marine animals alter their shape and texture using muscle contractions.
Except, instead of muscles, the researchers used flexible rubber, rigid mesh and air.
Cohen said main challenge was to figure out how to control the direction of the inflation of the soft rubber. The mechanical engineer, physicist and material scientist had to become balloon artists in order to conquer this problem.
“[Pikul] embedded an inextensible mesh in the elastomer, so when you inflated the combined structure, the elastomer stretched, but the mesh prevented any stretching wherever it was,” Cohen said. “So by cutting out any specific patterns of those constraining mesh, you were able to get the balloon to expand in the places you want.”
That technique, which they named CCOARSE, or Circumferentially Constrained and Radially Stretched Elastomer, is awaiting a patent.
The potential for applying this technology to the real world is widespread. Cohen said, the surface could be shaped to be a camouflage suit for stationed soldiers, disguise material for ecologists, prosthetics for actors, disposable manufacturing equipment for factories or even customizable toys for kids.
“I’d love to see what kids playing around with this kind of idea could come up with. There should be a whole industry of kids cutting out their own 3D shapes.” Cohen said. “It certainly ignites the imagination.”
Shepherd added that the deformable surface could eventually be used in virtual reality, for example, as a material simulator for an automotive designer.
Shepherd said he hopes to continue the advancement of this technology with alterations to the medium and by having the source of inspiration right on site.
“We do have a 300 gallon full-water aquarium in the lab, but getting the conditions right for an octopus is very difficult.” he said. “Once the conditions are appropriate, we will work with a funding source to get an octopus and give it a very good life while we study its camouflaging capabilities.”