Camouflage-artists can take a page from the cephalopod's book. This class of deep-sea creatures can bend its appearance at will, blending into its surroundings with an astonishing speed and accuracy. Now, a group of scientists at MIT are very close to reproducing the results with man-made technology.
Amazingly, scientists were able to make a sheet of nine cells that change color from white to black when heated.
The research team at MIT working on producing a suit of armor based on the cephalopod's camouflage has been working on this technology for months. In August, it reported that it was able to create a sheet of nine cells that could change luminosity and change color from black to white when they were exposed to light.
The team has improved the material even more since then. Now, the researchers are able to change the texture of the material as well. They constructed a new material out of a stretchable elastomer, a substance with viscosity and elasticity. They coupled the elastomer skin with mechanochromic molecules that change fluorescence when deformed. The team was able to deform the molecules using electric fields. The researchers so far are able to make patterns, such as circles, on the skin, using fluorescence.
The elastomer substance works a lot like the skin of the octopus, expanding and contracting in response to stress.
In a relaxed state, the muscles in the skin of the octopus are very small, Xuanhe Zhao, one of the researchers, says. But when the muscles contract, "they stretch that ball into a pancake, and use that to change color. The muscle contraction also varies skin textures, for example, from smooth to bumpy."
The team is working on a way to combine the mechanochromic molecules with a substance that can change colors. The elastomer is a flexible enough material to use for a wearable camouflage outfit.
Cephalopod skin uses three different layers combined to create its versatile camouflage. The bottom layer emits a white light; the middle layer produces cool tones like blue and green; and the top layer produces colored pigments like red, orange and black. The research team is looking for a way to create skins that can work together to a similar effect, to create an efficient and extremely versatile camouflage. Its next step is working with a substance that can change colors at will, and then combining that with another sheet that can change fluorescence.
