US boffins create darkest material ever

Blacker than a black cat in a coal cellar

US researchers announced yesterday they'd concocted the darkest material on the planet - a carbon nanotube substance so black it absorbs more than 99.9 per cent of light, Reuters reports.

In fact, the stuff's so unrelentingly black it's "30 times darker than a carbon substance used by the US National Institute of Standards and Technology as the current benchmark of blackness" and, with a total reflective index of just 0.045 per cent, is over three times blacker than the nickel-phosphorus alloy which currently holds the world's darkest material record.

The new black was created by researchers at Rice University in Houston in conjunction with a team from Rensselaer Polytechnic Institute in Troy, New York. It's made of carbon nanotubes, standing on end "much like a patch of grass". The tubes absorb some of the light falling on them, while the gaps between the "blades" capture the rest. The material's surface is also irregular, to cut reflection.

Pulickel Ajayan, head of the Rice University team, said: "All the light that goes in is basically absorbed. It is almost pushing the limit of how much light can be absorbed into one material."

The researchers have tested the material in visible light, and will now look at how it handles the infrared and ultraviolet spectrums, as well as wavelengths used in communications systems. Ajayan noted: "If you could make materials that would block these radiations, it could have serious applications for stealth and defense."

Civilian uses for the material might include solar energy conversion, infrared detection, or astronomical observation, Ajayan added.

The team is currently seeking a world's darkest material designation by Guinness World Records. If granted, it will complement Ajayan's 2006 Guinness World Record as "co-inventor of the smallest brush in the world".

The research will be published in the upcoming issue of the journal Nano Letters. ®

Bootnote

Cue obligatory Spinal Tap quote. As the band's Nigel Tufnel said: "It's like, how much more black could this be? And the answer is... none. None more black."

Sponsored: Driving business with continuous operational intelligence