Inspired by camouflaging sea creatures such as octopuses and squid, the machine too has a soft, rubbery body and is extremely flexible.
"Conventional robotics is a pretty highly developed area, and if you look at various robots you find that most are basically built on the body plan of a mammal,” said Professor George Whitesides, who authored the paper on the new robots.
"Our question is: Why do you have to do that? Why not think about organisms that are soft, that might have quite different structures and ways of moving and strategies for camouflage. And the obvious place to look is underwater."
The team previously published a paper that outlined the details of a soft robot that could bend and crawl under obstacles. Made from silicon-based polymers, the machine moved by pumping air through cylinders in its legs.
The scientists took the design, and covered the outer layer with a network of tiny channels. Dyes are then pumped in, allowing the robot to change its appearance at will.
In addition, hot or cold fluids can be pumped in that allow the machine to be thermally camouflaged, and can also pump into fluorescent liquids so it can glow in the dark.
Lead author Stephen Morin believes the machines could have medical applications.
He said, “The idea is that if you have a system that can simulate muscle motion very well and a system that can transport fluid, by combining those you can fabricate that device to fit a specific surgical problem. And in planning for surgery or training, you can use something like this in guilt-free way.”
Prof Whitesides thinks they could also be used in search and rescue missions.
He explained: “For that kind of application, having it be able to advertise itself, for example, in a way that stood out against the dark would be a good thing.”
“The nice thing about these systems is that their properties are very different from conventional robots. You get pretty complicated motions from pretty simple systems.
“For a mission like search and rescue, these kind of robots could in principle be throwaway. So if you took a $25,000 robot and sent it in and the building falls down, then that is a real issue. If you send one in which is $100 and the roof falls in, you really don't care.”