Though it can’t be blamed for last month’s art thefts in Rotterdam, there have recently been major advancements into making invisibility, or cloaking if we’re not being fantastical, that much closer to a reality, thanks to advancements in the use of meta-materials, man-made objects with unnatural properties. Claude Rains need not start rolling in his grave just yet, though.
In findings published in this month’s edition of Nature Materials, a Duke research team advanced upon previous designs from their own 2006 cloaking device, correcting some imperfections. Basically, the ideal process works as such: Shine a light at the device, seen above, and it splits the light waves, which travel around the device and meet up on the other side as if they’d traveled in a straight line through empty space. And since no light waves are technically hitting the object, our eyes see “through” the cloaked device.
The updates to the original design are described by Nathan Landy, a grad student working in the lab of senior investigator David R. Smith, William Bevan Professor of electrical engineering at Duke’s Pratt School of Engineering. One area they focused on was in decreasing areas of reflection along the boundaries of the device, and they succeeded just by changing the fabrication. Where the original design consisted of parallel and intersecting strips of fiberglass etched with copper, Landy and the team added copper strips to create a better material. The small reflections, which occurred along the edges and corners, were corrected by shifting the strips so that each met its own mirror image at each interface. And so, by eliminating almost all absorption of light by the device, the cloaking aspect works even better than before.
Beyond its uses in cloaking, Landy said this approach to transforming electromagnetic waves and light can be used in other ways, such as smoothing out twists and turns in fiber optics, making them seem straighter. Next up for the team is transferring these principles to three-dimensional objects, a wholly different can of worms.
It’s a pretty incredible achievement for the team, but I’m sure Chase banks have had a handle on this technology for years, since every time I deposit my paychecks, they seem to disappear.