An academic says he and his colleagues have demonstrated a major breakthrough in the quest for invisibility, and he has the military’s attention.
Boubacar Kante, a professor at the University of California-San Diego, and his colleagues tested the first effective “dielectric metasurface cloak.” That’s a fancy way of describing a super-thin, non-metal material that manipulates electromagnetic waves, including visible light and radio waves.
Those electromagnetic waves and how they come off an object are crucial to the ability to detect it. Radar can’t detect a plane without radio waves bouncing back to a receiver, and seeing requires light bouncing off an object and passing into your eyeball. Manipulating those waves could, in theory, prevent detection, and in certain conditions, Kante said he can do that.
“I am very excited about this work,” Kante told Army Times.
Kante said he has been in contact with a Defense Department project manager and expects to be submitting a proposal this month.
What makes this stuff unique?
In 2006 researchers demonstrated it was possible to absorb or direct electromagnetic waves around an object through a coating and make it “invisible”; it only worked on microwaves and in two dimensions. Advances since then helped lead Kante and his team (Li Yi Hsu and Thomas Lepetit) to a new material consisting of a layer of Teflon substrate with tiny ceramic cylinders embedded into it.
Kante cited two main breakthroughs: the ultra-thin material, and the use of the ceramics rather than metallic particles in the Teflon.
Previous cloaking efforts required materials as much as 10 times thicker than the wavelength being dodged. Missile guidance and marine radar wavelengths measure roughly 3 centimeters; that would require about a foot of coating. Kante said his material can work at 1/10 of the wavelength. Hiding from that same 3 cm wavelength would thus only require about a 3 mm coat. Different thicknesses (thinner) could be used for electromagnetic waves as small as those of visible light (which ranges from about 400 to 700 nanometers.)
What are the military benefits?
In case it’s not obvious: to hide. There are far-reaching and fairly obvious military implications to getting an object close to an objective. Unmanned Areal Vehicles and other planes, ships and anything else interested in dodging radar could have a use for it. And it could also be used as high-end camouflage for any background colors.
The Homeland Defense & Security Information Analysis Center is a Defense Department contractor tasked essentially to be a matchmaker for the Pentagon and academia/industry. Kayla Matola, research analyst for HDIAC, told Army Times the UCSD design is lighter and cheaper than anything else out there, and “basically what the military’s looking for” regarding cloaking capabilities.
“If anything this could provide the military with air superiority,” Matola said.
Are there limits?
Yes. First, even in theory, true invisibility remains a pipe dream; the objects cloaked still are in front of what’s behind them. But there are also limitations to visual camouflage and radar-masking capabilities.
Angle limitations lead the list. The experiment tested the cloak with light hitting at a 45 degree angle, and works effectively only within a 6-degree range of angles. Kante said his team is working on ways to expand that. His study states that the math behind the effectiveness of this experiment indicates a “large range” of angles should be possible.
Also, Kante said the technology does not allow for a cloak that can hide an object from both visual and radar detection; a given cloak will only work for a fairly narrow range of wavelengths.
So like my hover board, this is super expensive and a long ways out.
Actually, Kante says no on both counts.
“Basically, we are ready to make them right now,” Kante said of the current (albeit limited) capabilities.
He said ceramics are cheap and abundant. And he said that while no companies possess the capabilities to produce vast quantities of this cloaking material now, he said scaling up would not be difficult.
“There’s no fundamental roadblocks,” Kante said. “It would be easy to manufacture.”
Matola estimated that utilization of this technology probably sits in the 5-10 year range. The big question is just how fast the Army could test, decide whether and how to utilize, confirm efficacy and priority, find funding, and have industry make enough to slap it onto it’s toys.
The future is awesome. What else could this be used for?
Kante, who came to the U.S. from France in 2010, did not specifically set out to help generals hide spying and killing machines from the enemy.
While interested in meta-materials that can control waves as this technology, he said the primary goal he had been working toward was using the materials for cavities to trap light and store information for a long period of time. Using similar concepts as fiber-optics, which use light to transfer information rather than electricity, the simplified idea was to cut slower electricity out of computers and processors altogether.
Another application for the general field of manipulating waves revolves around solar power: Kante said in theory sunlight could be directed to a single point and captured as energy. He said his team has already submitted a proposal for a ceramic-based flat mirror that can direct sunlight to a certain point.
He’s also received interest from an interior design company.