A close-up image of the new material. A section has been removed to show the vertical nanotubes.
Engineers at Nasa have come up with a material that absorbs more than 99 per cent of all light that strikes it.
Absorbent material usually pulls in ultraviolet and visible light – but this new material also captures infrared and far infrared light.
The development has even taken fellow Nasa scientists by surprise, and it promises to open new frontiers in space technology.
The team of engineers at Nasa’s Goddard Space Flight Center in Greenbelt, Maryland, reported the findings recently at the SPIE Optics and Photonics conference.
An even closer view of the nanotube surface shows why some scientists refer to it as looking like shag-pile carpet.
John Hagopian, leading the team, said reflectance tests were extremely positive, showing that the material has 50 times more absorbtion qualities than its rivals.
He said: ‘Though other researchers are reporting near-perfect absorption levels, mainly in the ultraviolet and visible, our material is darn near perfect across multiple wavelength bands – from the ultraviolet to the far infrared.
‘No one else has achieved this milestone yet.’
The material is a thin coating of carbon nanotubes – hollow and multi-walled tubes about 10,000 times thinner than a strand of human hair.
They stand at 90 degrees from the surface they coat, which Nasa scientists have referred to as looking like shag-pile carpet.
It can be applied to a variety of surfaces, including silicon, silicon nitride, titanium, and stainless steel – the materials most commonly used in space science instruments.
Nasa is already thinking about practical applications for the material – the most obvious being as light-suppression on sensitive equipment.
The tiny gaps between the tubes collect and trap background light to prevent it from reflecting off surfaces and interfering with the light that scientists actually want to measure.
Because only a small fraction of light reflects off the coating, the human eye and sensitive detectors see the material as black.
The material could dramatically slash light reflected off deep space equipment that is already straining to detect the faintest and farthest light sources.
Less obvious, however, is the fact that the material could also be used as a coolant.
The blacker the material, the more heat it radiates away, so the coating could be used on devices that remove heat from instruments and radiate it away to deep space.
Finally, it is a lot lighter than other materials that off less absorbtion – and weight is a critical factor in any payload being sent into space.
Goddard engineer Manuel Quijada, who co-authored the SPIE paper and carried out the reflectance tests, said: ‘We are a little surprised by the results’.
He added: ‘We knew it was absorbent. We just didn’t think it would be this absorbent from the ultraviolet to the far infrared.’
Goddard scientist Ed Wollack summed it up by saying: ‘This is a very promising material. It’s robust, lightweight, and extremely black. It is better than black paint by a long shot.’
Via Daily Mail