Get ready to break out the eyeliner and the candelabras, because the Army is going goth.
In its latest round of solicitations for small businesses, the Army is asking for proposals for super-black material. That is, material so black that it absorbs 99 percent of all light. But it isn’t really black paint, exactly. The plan is to use either an “antireflective coating or surface treatment process for metals” to absorb stray light “in the ultraviolet, visible, infrared, and far-infrared regions.” This, the Army hopes, will boost the quality of high-resolution cameras, while also cooling down sensitive electronics. Or to put it another way: The Army needs the color black to reflect its icy-cold heart.
Another curious thing is that the program is being run out of the Army’s Program Executive Office Ammunition at the Picatinny Arsenal, a main center for the Pentagon’s experiments in all sorts of weapons: from rifles and tank cannons to directed-energy weapons. But the purpose of the solicitation isn’t much more specific than described. “Simply put, it’s too early yet to speculate on where the technology(s) will go,” Frank Misurelli, an Army spokesman at Picatinny said in a statement provided to Danger Room. ”Possibly in a few months, after an contract has been awarded, more information may become available.”
But for whatever the Army wants to fade to black, it seems that regular black isn’t good enough. This is because most black paint will absorb only around 90-95 percent of light, with the other 5-10 percent reflected back outwards. For a high-resolution camera, that stray light can bounce back into the lens and interfere with the quality of an image. It’s even a problem for NASA’s ultra-deep-space sensors. In the extreme coldness of space, black paint turns a silver-y color, which increases heat and can interfere with infrared-detecting instruments.
But wait, doesn’t black get really hot when hit with light, like wearing black clothes during the summer? The answer is: sorta. Black is really good at absorbing heat, but is also really good at radiating heat away. This is why cooling fins, radiators and engines for cars and trucks are often painted black. In 2011, NASA developed a carbon-nanotube coating that absorbed between 98-99.5 percent of light, depending on the wavelength. Nor do the coating’s thin layers of nanotubes change color in extreme cold. They absorb more light, and help radiate heat away from instruments, keeping them cold.
The Army could go another route. A second option uncovered by Britain’s National Physical Laboratory involves immersing an object in a solution of nickel and sodium for several hours, which blackens the color, and then taking it out and dunking it in nitric acid for a few seconds. According to New Scientist, this creates an alloy pock-marked with tiny microscopic craters that prevent light from bouncing away.
Finally, the Army also hopes to expand the materials to “optical glass surfaces” — camera lenses, in other words — while testing to see whether “it will be able to survive in a military environment.” The material should also come in “multiple surface colors” and be able to “selectively exhibit earth color instead of broadband absorption.” And another hope is to use the materials to absorb water to cool down equipment. See, it’s tough out there being goth, but it doesn’t mean you can’t do it in comfort.
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