Scientists Create New and Improved 'Invisibility' Coat
Scientists at Duke University have created the first invisibility cloak that perfectly hides cen...
There are some caveats, of course. You didn’t really think you’d soon be sneaking away with Ron or Hermione (delete as applicable) into the woods, did you? For now, the Duke invisibility cloak only works with microwave radiation — and perhaps more importantly, the cloak is unidirectional (it only provides invisibility from one very specific direction). The big news here, though, is that it is even possible to create an invisibility cloak of any description. It is now just a matter of time before visible-light, omnidirectional invisibility cloaks are created.
In theory, invisibility cloaks operate by bending electromagnetic waves around objects — so that instead of seeing the object, you see what’s behind the object. Negative index metamaterials get you most of the way, but they still need to be arranged in such a way that the illusion is perfect. To get around a 3D object, you have to turn a corner at some point — and previous cloaks have struggled to fashion metamaterials that bend waves around corners without causing reflections, which ruin the illusion. In this case, Nathan Landy, a graduate student at Duke University, tweaked the metamaterial itself, and then fashioned it into a diamond, which is apparently the best shape for minimizing reflections.
The end result is an invisibility cloak that can perfectly hide a 3×0.4-inch (7.5x1cm) cylinder from microwave radiation. This obviously isn’t quite as awesome as an invisibility cloak that operates in the visible light spectra, but microwaves are still very important in the realms of telecommunications and defense (think radar, and the ultimate stealth vehicles). A very basic application might be in fiber optic networks, where invisibility cloaks could be used to bend light around corners without attenuating the signal.
The next step for the Duke University team is to create an omnidirectional, 3D microwave invisibility cloak. Then, eventually, when we work out how to create metamaterials that can bend visible light in interesting ways, we might get an actual invisibility cloak. That’s a few years away yet, though.
For more on the science behind invisibility cloaks, watch the video below.
Source: Extreme Tech