Ancient organisms like squids, cephalopods, octopus and cuttlefish could hold the key to making soldiers of the future invisible, US scientists say.
Researchers at the University of California, Irvine, said they have discovered a way to use proteins in the cells of pencil squid to develop "invisibility stickers" that could be worn by ground troops, CNN reported on Saturday.
"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," said Alon Gorodetsky, assistant professor of chemical engineering and material sciences at the university.
"You can draw inspiration from natural systems that have been perfected over millions of years, giving us ideas we might never have been able to come up with otherwise," he said.
Gorodetsky and his team focused on specialised squid cells known as iridocytes, which contain a unique light-reflecting protein called reflectin.
They were able to engineer E.coli bacteria to synthesise reflectin and coat the protein on to a packing tape-like surface to create the "invisibility stickers".
Researchers said these reflectin-coated stickers could be changed into virtually any colour with a chemical or mechanical stimulus.
"There is a lot of flexibility in how one can deploy this material, essentially, by taking the stickers and putting them all over yourself, you could look one way under optical visualisation and another way under active infrared visualisation," Gorodetsky said.
The technology, however, is not ready to be used in combat zones yet as researchers work to develop an adaptive camouflage system, in which multiple stickers are able to work in sync and respond to varying infrared wavelengths.
"We've developed stickers for use as a thin, flexible layer of camo(uflage) 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 visualisation," Gorodetsky said.
The researchers' work was presented at the 2015 American Chemical Society national meeting.
Squids unique light-reflecting protein called reflectin.