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 davester666 on Thursday April 23 2015, @07:38AM
It will require that we harvest every single cuttlefish and throw them all in vats of molten steel.
But some architect will make a cool building out of it...
(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.
(Score: 1) by MeatBacon on Thursday April 23 2015, @03:03PM
Shape Memory alloys, like Nitinol, are not a one-time-deal. They are usually formed into the shape desired, then heat-treated. After that, heating the alloy causes it to return to the shape it was heat-treated in.
Thus, eyeglass frames are made into their final shape, heat-treated, and when you sit on them, throw em in some boiling water, presto.
This can be repeated relatively indefinitely.
The alloy can also be reshaped, then re heat-treated, to 'lock in' a new shape 'memory'. Your eyeglass frames could be bent into a little robot arm sculpture for your desk, and then heated to above its transition temperature, after which it would not be glasses anymore, but would return to its sculpted form when heated.
http://en.m.wikipedia.org/wiki/Nickel_titanium [wikipedia.org]