Researchers Create First Three Dimensional Cloaking Device

Over the past several years, scientists have made several breakthroughs in creating cloaking devices, bringing us ever closer to Harry Potter's cloak of invisibility. Such breakthroughs though, until now have involved objects that exist in just two dimensions, which means, for example, types of radiation making their way across a glass slide. Now however, physicists from the University of St Andrews in Kentucky have succeeded in building a cloaking device that is capable of hiding 3D objects. In their paper published in the New Journal of Physics, the team describes how their new device uses metamaterials to hide objects from view as seen from any angle. A huge step forward in the science of cloaking.

As the researchers describe in their paper, their technique relies on creating a certain kind of material known as a metamaterial, which is a unique type of material, in this case, a kind of metal, that can be made to reflect and refract light in desired ways. But that's just the beginning, to make a true cloak, the metamaterial must be flexible or it will only work with one object. Thus, the researchers, after much trial and effort, managed to mix together a variety of metals in just the right amounts that allowed for flexibility while also offering the reflecting and refraction necessary to move light around the object.

The whole idea works because light is the means by which we see everything around us. Light striking a computer keyboard bounces back to us and through our pupils into the back of the eyes to allow us to see what we're typing. If something were to be placed under our keyboard that caused the light behind it to bend before it hit the keyboard, and then caused it to bend back on the other side before it came to our eyes, we'd see nothing but the table the keyboard is sitting on. And that's how cloaking devices work.

The breakthrough that allowed the physicists to create the cloaking device really came down to inventing the right mix of refracting and reflecting properties in the material they were working with. Both components cause light to first bend away from an object and then to bend back, just as water is pushed to the side when it encounters an island in the middle of a river. No device is needed on the other side to bend it back, because the cloak uses the force that light applies on the metamaterial to cause the bend, then after the force is out of range, the light returns to its original path.

The new cloaking device won't be on the market anytime soon, as the experiment used elements too small to be seen by the human eye. Thus, a lot more research needs to be done before it can be sized up and expanded to cloak everyday objects.