But the latest on the cutting-edge of concealment focuses on unpacking the mystery of color-shifting squid.
When they're not being concealed in a lightly fried batter on your plate, these cephalopods are masters of camouflage, using their light-reflecting skin to seamlessly blend into their environment, according to researchers from the University of California at Irvine. Using a protein found in squid skin, the scientists have created "invisibility stickers" that may help soldiers disguise themselves, even from infrared camera.
"Soldiers wear uniforms with the familiar green and brown camouflage patterns to blend into foliage during the day, but under low light and at night, they're still vulnerable to infrared detection," Dr. Alon Gorodetsky said in a news release. "We've developed stickers for use as a thin, flexible layer of camo with the potential to take on a pattern that will better match the soldiers' infrared reflectance to their background and hide them from active infrared visualization."
The protein Gorodetsky's team was able to isolate is known as reflectin, and it allows the animal to alter the way its skin reflects light and change its coloration within a split second.
The team was able to coat reflectin onto a surface "similar to common household packing tape," according to a video (below) released by the American Chemical Society. What resulted is a sheet of invisibility stickers that can be used for camouflage.
Although it's not yet ready for real-world use, the tentative idea, Gorodetsky explained, is for soldiers to carry a roll of invisibility stickers that could be applied to their uniforms as soon as they needed to disappear.
"We're going after something that's inexpensive and completely disposable," Gorodetsky said. "You take out this protein-coated tape, you use it quickly to make an appropriate camouflage pattern on the fly, then you take it off and throw it away."
The stickers application might not be limited to military use, he added. The team has floated the idea of using the tape in clothing that could, depending on the wearer's needs, trap or reflect body heat.