12-02 :: February/March 2012
nanotimes News in Brief
This close-up view (only about 0.03 inches wide) shows the internal structure of a carbon-nanotube coating that absorbs about 99% of the light that strikes it. A section of the coating, which was grown on smooth silicon, was purposely remo- ved to show the tubes‘ vertical alignment. © Stephanie Getty, NASA Goddard
material is bathed in carbon-containing feedstock gas. The tests indicate that the nanotube material is especially useful for a variety of spaceflight applica- tions where observing in multiple wavelength bands is important to scientific discovery. One such appli- cation is stray-light suppression. The tiny gaps bet- ween 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 advantage over other materials is that our mate- rial is from 10 to 100 times more absorbent, depen-
ding on the specific wavelength band,” Hagopian said.
“We were a little surprised by the results,” said God- dard engineer Manuel Quijada, who co-authored the SPIE paper and carried out the reflectance tests. “We knew it was absorbent. We just didn‘t think it would be this absorbent from the ultraviolet to the far infrared.”
“This is a very promising material,” Wollack said. “It‘s robust, lightweight, and extremely black. It is better than black paint by a long shot.”