Very black is the new black

Engineers get dark with carbon nanotubes.

Engineers from the Massachusetts Institute of Technology, US, say they have created a material that is 10 times blacker than anything previously reported.

Made from vertically aligned carbon nanotubes (CNTS) – microscopic filaments

of carbon grown on a surface of chlorineetched aluminium foil – it captures more than 99.96% percent of any incoming light.

The researchers reported their findings

in the journal Acs-applied Materials and Interfaces and also showcased the achievement with an exhibit at the New York Stock Exchange.

Redemption of Vanity, a collaboration with MIT artist-in-residence Diemut Strebe, featured a 16.78-carat natural yellow diamond coated with the new material, which makes the brilliantly faceted gem appear as a flat, black void.

Finding a blacker black was not actually the research aim. Brian Wardle and Kehang Cui were experimenting with ways to grow carbon nanotubes on electrically conducting materials such as aluminium.

After finding a way to remove a troublesome oxide layer that forms on aluminium when it’s exposed to air, acting as an insulator, they were able to grow carbon nanotubes on the aluminium at much lower temperatures and, as expected, the combination of CNTS on aluminium significantly enhanced the material’s thermal and electrical properties.

What surprised them was the colour. The rest, as they say, is history.