Using an effect similar to that of the mirage created by heat waves coming off of the road, scientists from Duke University have developed an invisibility cloak. This first attempt, however, is designed to prevent microwaves from detecting the cloaked object - in this case a metal cylinder. Microwaves, like light and radar, bounce off objects and create shadows, allowing detection by instruments. The invisibility cloak, which is made of metamaterials (mixtures of metal and circuit board materials such as ceramic, Teflon or fiber composite), reduces both the image of the object itself and its shadow.

While this is certainly a technological breakthrough, coming only five months after the publication of the possibility of such a device, the Duke researchers comment that they are already working on a much better design. "The first working cloak was in only two dimensions and did cast a small shadow. ... The next step is to go for three dimensions and to eliminate any shadow."

Conceptually, the development of a prototype having the same effect on light waves is said to be straightforward; it's the engineering that presents the challenge. Additionally, scientists are playing with the idea of potentially shielding an object against acoustic waves, which would reduce the effect of vibration or seismic activity in a region.