When it comes to disappearing in plain sight, Harry Potter has the invisibility cloak, Solid Snake, from the video game “Metal Gear Solid,†has his active camouflage, and soon, the U.S. military might have the “dielectric metasurface cloak.â€
Boubacar Kante, a professor at the University of California-San Diego, and his colleagues recently tested the cloak and plan on submitting their proposal for it to the Pentagon this month, according to a Sunday report in the Army Times.
The cloak, the report explains, is actually a thin ceramic surface that is layered on top of say, a drone or ship or any other object that the user would want to make disappear from view or radar. The coating then has the ability to manipulate electromagnetic waves at varying wavelengths—from visible light to radio waves.
What makes Kante and crew’s cloak so special is how thin the coating is. According to the Army Times report, previous “invisibility tests†in 2006 used different material (in past cases Teflon) that required that the coating, or cloak, be 10 times thicker than the wavelength being avoided.
So for instance, if you were trying to hide a Predator drone from a missile guidance radar that has a 3cm wavelength, the older Teflon coating would have to be 30cm thick.
Kante’s new ceramic “cloakâ€, however, works at 1/10th the wavelength. That means his coat, to dodge the same missile guidance radar, would only have to be 3mm thick.
The Army Times report, citing this math, notes that since Kante’s coat is so thin, it could be used even to manipulate the electromagnetic waves at the visible light level, hence it could make something almost invisible. Complete invisibility, however, is near impossible because the object will always have a background that it could be discerned from.
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The technology is not without limitations. Currently the biggest issue is the angle in which the wavelengths hit the material. Right now, it only works with light hitting the cloak at a 45-degree angle with a 6 degree give or take, according to the report. Kante also told the Army Times that the coating can only be configured—because of thickness—to one type of “invisibility†at a time. This means you could coat on object to avoid visual detection or radar detection, not both.
According to the report, Kante believes mass production of the coating material could be relatively easy and Kayla Matola, a research analyst for Homeland Defense & Security Information Analysis Center was quoted as saying that, if approved, the coating could be fielded in the next five to ten years.