Two researchers have designed a material that can change color and texture within seconds of being exposed to light, the way cuttlefish can:
"Changing color is relatively easy; a TV can do that,” said Li Tan, an associate professor a UNL, in a press release. “Changing texture is harder. We wanted to combine the two."
In research published in the journal Applied Materials and Interfaces, the researchers were able to produce this effect by placing colloids inside a multilayered structure consisting of “a thermal insulating base layer, a light absorbing mid layer, and a liquid top layer.” Colloids are basically a material in which tiny particles are suspended in a liquid and remain evenly dispersed. In this case, the particles are made from soda lime, glass, or copper.
In practice, when a laser light strikes the material, the light begins to warm the pixels into which it has been absorbed. (These pixels are always different than the kind of laser light hitting them; for example, green pixels absorb red light.) This rise in temperature leads to tiny ruptures on the surface of the material or internal eruptions within the material.
For now the effect seems to be closer to a shape memory alloy, which is a one-time affair. Still, cool stuff.
(Score: 2) by quadrox on Thursday April 23 2015, @07:43AM
Since the material will change based on the light shining directly onto the surface, the material is limited to imitating what is in front of the camouflaged surface. True camouflage needs to imitate what is behind a surface, not what is in front.
Of course, in places that have a largely uniform look, and where what's in front looks mostly the same as what's behind this will work just as well. But in many places this just wouldn't be useful at all.