The first large-scale invisibility cloak that hides objects from visible light

James Plafke

http://www.extremetech.com/extreme/179973-the-first-large-scale-invisibility-cloak-that-hides-objects-from-visible-light
Among all of the sci-fi tech we see in movies — space and time travel, shrink rays, weaponized lasers — the invisibility cloak always seemed like the one piece of sci-fi technology that researchers could never create. Oddly, though, in recent times it has been thrust into the forefront of in-development science fiction technology. Now researchers at the University of Central Florida have managed to create a large-scale invisibility cloak that masks the spectrum of visible light. This is significant, as invisibility cloaking has previously only been possible for very specific wavelengths of radiation (say, microwaves). Visible light, which covers a broad swath of terahertz-level frequencies, has so far proven very hard to mask.

The real-life invisibility cloak is generally not what you picture when you hear the term. Generally, you picture a Harry Potter-style robe that completely erases your visual presence from an environment. In more “realistic” movies (relative to casting magic spells from a wand, at least), invisibility cloaks bend light around an object, making it look as if it’s covered in a liquid mirror. In real life, invisibility cloaks don’t come remotely close to the movies; for instance, they often tend to be solid objects that simply play perspective orreflective tricks on the eye. Now, researchers at a certain writer’s alma mater, University of Central Florida, have created a cloak that actually bends and masks visible light using a fishnet-type of metamaterial.

The metamaterial fishnet is composed of metal and dielectric composite films, created using a nanotransfer printing method. The films are layered in such a way as to create a fishnet-like pattern, which in turn allows the control of visible-spectrum light. [Research paper: DOI: 10.1002/adom.201470019]

The printed metamaterial sample is small — about 0.6 square inches (or four square centimeters) — but thanks to the fact that it’s a printing process, the UCF team feels it can print the material on a larger-scale for more practical applications, such as for use on fighter jets.

Debashis Chanda, a UCF assistant professor who led the project, noted that while invisibility cloaks won’t be on store shelves anytime soon (or ever), the team has been contacted by multiple companies looking to help fund more research on the matter. One of the interested parties is Lockheed Martin, so there is some high-profile interest behind the tech. For now, though, you shouldn’t salivate at the thought of being able to infiltrate the Monday morning meeting at work every week to find out if your coworkers are actually doing anything productive in there.