Tuesday, November 15, 2011

None More Black


Now that they're not currently exploring space, NASA engineers directed their efforts locally, and have produced a material that absorbs more than 99 percent of the ultraviolet, visible, infrared, and far-infrared light that hits it.

The coating is a thin layer of carbon nanotubes about 10,000 times thinner than a strand of human hair. Grown on silicon, silicon nitride, titanium, and stainless steel, a thin layer of iron is positioned as an underlayer and then heated to near 1,382 degrees Fahrenheit. At the same time, the material is bathed in carbon-containing gas.

Currently, space instrument developers apply black paint to help prevent stray light from ricocheting off surfaces, but paints absorb only 90% of light that strikes it. Additionally, black paints do not remain black when exposed to cryogenic temperatures, and are mixed with conductive metal epoxies to keep them from losing their absorptive and radiative properties. This new super-black material could be used instead with greater efficiency while decreasing the weight of the coating, and instruments would be able to detect more faint wavelengths as the multiple frequencies of light are absorbed.

"It's robust, lightweight, and extremely black. It is better than black paint by a long shot."

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