Carbon nanotube ‘space camouflage’ coating invented
Tiny carbon tubes can be used to hide three-dimensional objects from view, according to a team of researchers.
The nanotubes are one-atom thick sheets of graphene wrapped into cylindrical tubes.
Engineers from University of Michigan found they could be used to obscure objects so that they appeared to be nothing more than a flat black sheet.
The team suggest “forests” of the material may one day be used to cloak spacecraft in deep space.
The group says the technology works because the nanotubes’ “index of refraction [is] very close to that of air”.
This means they slow down light to a similar degree.
As a result there is very little scattering of light as it passes from the air into the layer of nanotubes.
Haofei Shi, the report’s lead author, said the material “acts as a perfect black cloth that can completely conceal the 3D structure of the object”.
To put his theory to the test his team etched a tiny 3D image of a tank out of silicon.
When viewed through a microscope the tank’s contours could be clearly seen under white light.
However, when the nanotube coating was applied the tank’s structure disappeared and could not be distinguished from the background.
The research will be published in an issue of the Applied Physics Letters journal.