Duke University creates 'perfect' one-directional microwave cloak, might lead to stealthier vehicles

Most attempts at cloaking, no matter the slice of spectrum, usually leave clues as to what's there -- even microwave cloaks can spoil the surprise through reflections. At Duke University, researchers have licked some of those past problems with the first instance of a flawless microwave cloaking scheme. By crafting a special diamond-shaped cloak where the light properties stay consistent at the corners, the school's Nathan Landy and David Smith have successfully shielded a 3-inch wide cylinder from microwave detection without a hint that something was amiss. The gotcha, as hinted by the shape, is a two-dimensional nature that gives away the secret at less than ideal angles. Duke suggests that it still has the groundwork for something that could be vital for communications or radar -- we can imagine a stealth aircraft or ship in the far-flung future that could actively mask itself from radar signals. It's not quite the optical illusion we're looking for, but a refined version of the Duke project might be enough for a rare practical use of cloaking when fantasies are much more common.