Undersea creatures such as octopuses, squid and cuttlefish have an amazing ability to quickly blend in with their surroundings. Now, taking a cue from these animals, scientists have created their own kind of camouflage that does the same thing.
These animals, called cephalopods, don't just change the color of their skin when blending in, but they can also affect the shape and texture of their skins, seemingly becoming one with their surroundings. And all of this happens without any input from the creatures' brains.
Obviously, camouflage that does this in the man-made world would be extremely valuable, so scientists studied cephalopods to create something that reacts similarly. A team from the University of Houston and the University of Illinois at Urbana-Champaign developed flexible sheets with light sensors. Inside the sheets is a dye that responds to heat. The sheet works by detecting light, which prompts it to change its color.
"This is by no means a deployable camouflage system but it's a pretty good starting point," says John Rogers, one of the lead scientists on the project.
The technology for the color-changing sheets are directly inspired by cephalopods in nature. Cephalopods' skin contains chromatophores, tiny organs with pigments that reflect light. Small muscles control the chromatophores, while opsins sense light and allow their skins to "see" their background.
By comparison, the flexible camouflage sheet contain their own form of chromatophores: heat-sensitive dyes that change colors based on room temperature. A thin piece of silver underneath that reflects light. Underneath the light reflective surface is a diode that heats up the dye, acting as the "muscles" of the camouflage. Each corner of the sheet has notches that lets in light, allowing the material to "see" its surroundings.
In tests, the researchers demonstrate how the camouflage sheet adapts to changing light patterns in about one to two seconds.
The camouflage isn't as effective as that of cephalopod skin, but scientists feel confident that their system can be improved upon. Currently, it's much slower than the skins from nature that inspired it, and it uses a lot of power. The current prototype is also small: only about one square centimeter in size.
"Real cephalopods are capable of levels of active camouflage orders of magnitude more sophisticated than our system," says Rogers. "But we hope to eventually design man-made systems that rival those we see in biology."
Researchers point out that although this technology obviously has implications for military use, it could also be used in fashion and interior design.
