Scientists have developed a color-changing device inspired by octopuses and their natural camouflaging techniques.
The research, carried out at the University of Houston and University of Illinois at Urbana–Champaign, looked at how the skins of octopuses, squid and cuttlefish can change color so rapidly. From there, researchers were able to design a heat-sensitive sheet that quickly changes color when detecting light.
At room temperature the flexible sheet is black. Once the device’s top layer, which contains a heat-sensitive dye, detects light it becomes transparent. True, this is hardly a rainbow of hues, but scientists believe it is the first step to developing a camouflage material for human use.
“[The device] is by no means a deployable camouflage system but it’s a pretty good starting point,” said a lead researcher, John Rogers of the University of Illinois at Urbana–Champaign, to National Geographic.
Popular Mechanics broke down the layers of the new device as follows:
The top layer of the new device is loaded with a temperature-sensitive dye that appears black at low temperatures and clear at temps above 116 degrees F. This dye-filled layer sits on top of a layer of white reflective silver tiles, an ultra-thin layer of silicon circuits that control the dye's temperature, and a transparent silicone rubber foundation. All together, this stack measures less than 200 microns thick. (The average human hair is 100 microns wide.)
Underneath this flexible sandwich is a base layer containing an array of light-sensing photodetectors. The corners of each dye-filled pixel and silver tile above this photoreceptor layer are notched, creating gaps that are like holes in a mask, allowing light to get through to the photoreceptors so they know how and when to change color. This adaptive camouflage system can respond to changing patterns of illumination within just one to two seconds.