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nanotimes News in Brief

12-02 :: February/March 2012

Materials // NASA Develops Super-Black Material That Absorbs Light Across Multiple Wavelength Bands

© Based on Material by NASA N

ASA engineers have produced a material that absorbs on average more than 99% of the

ultra-violet, visible, infrared, and far-infrared light that hits it – a development that promises to open new frontiers in space technology.

The team of engineers at NASA‘s Goddard Space Flight Center in Greenbelt, Md., reported their findings recently at the SPIE Optics and Photonics conference, the largest interdisciplinary technical meeting in this discipline. The team has since recon- firmed the material‘s absorption capabilities in additi- onal testing, said John Hagopian, who is leading the effort involving 10 Goddard technologists.

“The reflectance tests showed that our team had extended by 50 times the range of the material’s absorption capabilities. 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,” Hagopian said. “No one else has achieved this milestone yet.”

The nanotech-based coating is a thin layer of multi- walled carbon nanotubes. They are positioned verti- cally on various substrate materials much like a shag

This high-magnification image, taken with an electron mi- croscope, shows an even closer view of the hollow carbon nanotubes. A coating made of this material is seen as black by the human eye and sensitive detectors because the tiny gaps between the tubes collect and trap light, preventing reflection. © Stephanie Getty, NASA Goddard

rug. The team has grown the nanotubes on silicon, silicon nitride, titanium, and stainless steel, materi- als commonly used in space-based scientific instru- ments. To grow carbon nanotubes, Goddard tech- nologist Stephanie Getty applies a catalyst layer of iron to an underlayer on silicon, titanium, and other materials. She then heats the material in an oven to about 750° C (1,382° Fahrenheit). While heating, the