A study on carbon nanotubes proves that it is one of the most robust material known till now. The carbon nanotubes are compact cylinders made of carbon lattices with the thickness of about one atom.
A team of researchers from the University of Michigan have utilized the low refractive index of aligned nanotubes with low density to discover a new application of causing three-dimensional objects to be seen as just a flat, black sheet.
Scanning electron microscope images showing how the nanotube coating camouflages the tank structure against a black background
The material’s refractive index is a measure of how the material surpasses the passage of light through them. The refractive index of the carbon nanotubes forests is very much less and close to that of air. The light passing from air into a nanotubes layer is likely reflected and scattered, since both the air and nanotubes have closely similar refractive indices.
The University of Michigan’s research group found that they can use this low refractive index property of the nanotubes to visually conceal the object’s structure. According to the journal “Applied Physics Letters” of American Institute of Physics, the scientists has developed a three dimensional image of the tank made of silicon. The reflections revealing the contours of tank is produced by illuminating the three dimensional image with white light. When a carbon nanotube forest is developed on top surface of the tank by the researchers, the light is absorbed by the tank’s nanotube coating, resulting in a three dimensional flat, black sheet.
Researchers finally stated that the carbon nanotube coatings absorbs light without scattering, which makes it to hides an object generating a black background like a deep space. Researchers also added that in such a scenario, the carbon nanotubes forest represents a perfect magic black cloth, which can hide the three dimensional objects.
Source: http://www.aip.org/