March 30, 2015
Squid-inspired invisibility camo for soldiers
Drawing inspiration from a squid’s ability to blend seamlessly into the background to hide from their prey, researchers at the University of California at Irvine have developed a new “invisibility sticker” that could prevent soldiers from being spotted with infrared cameras.
According to Discovery News, UCI’s Dr. Alon Gorodetsky and his colleagues developed new camouflage designs based on iridocytes, an unusual type of cell found in squid skin that contains layers made up of a protein called reflectin. They coaxed bacteria to produce reflectin, and then used it to coat a hard substrate similar to packing tape in order to create the “invisibility sticker.”
The researchers, who showed off the fruits of their labor last week at the 249th National Meeting & Exposition of the American Chemical Society (ACS), went on to explain that the material can adhere to a variety of different surface types, including cloth uniforms.
“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. Gorodetsky explained. “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.”
He explained that a squid uses a biochemical cascade to change the thickness and spacing of the reflectin layers, which in turn alters how the cells reflect light and the coloration of the skin. By exposing the coated substrate to acetic acid vapors, they found that the film began swelling and then disappeared when viewed with an infrared camera.
[VIDEO: Squid electric skin]
“What we were doing was the equivalent of bathing the film in acetic acid vapors -- essentially exposing it to concentrated vinegar. That is not practical for real-life use,” Dr. Gorodetsky said. That’s where the sticky-tape like substance comes in, since it provided a mechanical trigger that could be realistically used in military operations – though it is not yet ready for field use.
The UCI researcher said that he envisions soldiers or security personnel one day being able to carry a roll of invisibility stickers in their packs, using them to cover their uniforms as needed. He added that his team was looking to create something that was “inexpensive and completely disposable. 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.”
A work in progress
Before that can become a reality, however, Dr. Gorodetsky and his fellow researchers have several issues to overcome. For instance, they have to figure out a way to increase the brightness of the stickers. In addition, to make a truly adaptive camouflage system, they will need to make it so that several stickers respond in exactly the same way at exactly the same time.
They are also working on ways to make the stickers more versatile. While the current version of the stickers can reflect near-infrared light, the UCI team is looking to enhance the materials so that they can also work at mid- and far-infrared wavelengths, allowing them to be used to thwart thermal infrared imaging. They may also have non-military uses, such as in clothing capable of trapping or releasing body heat as needed to help keep people comfortable at all times.