In the scientific race to build fantastical devices such as invisibility cloaks, University of Arizona engineering professor Hao Xin is at the forefront.

His new discovery uses metamaterials – artificial materials engineered to bend electromagnetic, acoustic and other types of waves in ways not possible in nature – to take us one step closer to building microscopes with superlenses that see molecular-level details, therefore bringing us closer to the reality of building shields that could conceal military airplanes and people.

By using a 3-D printer to make metamaterials, Xin is able to configure objects in precise geometrical patterns to bend waves of energy in unnatural ways. Doing this allows researchers to tap into a property call negative refraction, meaning they can bend waves backwards.

In the future, someone wearing a cloak that has been manufactured with these artificially designed refraction properties would appear invisible.

(more…)

“Any sufficiently advanced technology is indistinguishable from magic.”
-Arthur C. Clarke

Doctoral student Joseph Choi is pictured with a a multidirectional `perfect paraxial’ cloak using 4 lenses.
Credit: University of Rochester Newscenter

Scientists at the University of Rochester have developed a real-world invisibility cloak. This Harry Potter-esque cloak has the ability to hide objects from view, and is surprisingly inexpensive due to the readily available materials in its novel configuration.

“There’ve been many high tech approaches to cloaking and the basic idea behind these is to take light and have it pass around something as if it isn’t there, often using high-tech or exotic materials,” said John Howell, a professor of physics at the University of Rochester.

The Rochester Cloak is different from its predecessors, because unlike invisibility cloaks of the past, this cloak maintains an object’s invisibility even when the viewer changes his or her angle and creates a different viewpoint.

“This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum,” said Joseph Choi, a PhD student at Rochester’s Institute of Optics who is working with physics professor John Howell at the university.

(more…)