[Univ of Michigan News Service]
A carbon nanotube coating developed at the University of Michigan acts as a “magic black cloth” that conceals an object’s three-dimensional geometry and makes it look like a flat black sheet….
“It’s not cloaking, as the object can still cast a shadow. But if you put an object on a black background, then with this coating, it could really become invisible.” …
Here’s how the new coating works: Human eyes perceive an object based on how it reflects or scatters light. The “refractive index” of this new coating is similar to that of air, meaning light traveling through air doesn’t scatter or reflect when it hits the coating.
It’s well known that carbon nanotubes are capable of absorbing light, but the researchers were able to push it to such a high percentage by spacing them just right.
The “perfect black” material Guo’s team created for this coating has a host of varied applications. It could possibly be used in display screens for ultra-high contrast and a crisper picture. …
Read the full story here: http://www.ns.umich.edu/new/releases/20088-perfect-black-coating-can-render-a-3d-object-flat-raises-intriguing-dark-veil-possibility-in-astronomy