A Practical Way to Make Invisibility Cloaks

The new printing method makes it possible to make a large sheets of metamaterials, a new class of materials designed to interact with light in ways no natural materials can. For few years, researchers working on these materials have promised invisibility cloaks. Metamaterials that interact with visible light have previously not been made in pieces larger than hundreds of micrometers. Metamaterials are made up of intricately patterned layers, often of metals. Rogers has developed a stamp based printing method for generating large pieces of one of the most promising types of metamaterial, which can make near infrared light bend the "wrong" way when it passes through. Materials with this so called negative index of refraction are particularly promising for making superlenses, night vision invisibility cloaks, and sophisticated waveguides for telecommunications. I think the night vision one so cool. Roger Illinois group starts by molding a hard plastic stamp that's covered with a raised fishnet pattern. The stamp is then placed in an evaporation chamber and coated with a sacrificial layer, followed by alternating layers of the metamaterial ingredients silver and magnesium fluoride to form a layered mesh on the stamp. The stamp is then placed on a sheet of glass or flexible plastic and the sacrificial layer is etched away.

http://www.technologyreview.com/computing/37720/page2/