Cloaking

The concept of an invisibility cloak sounds like pure science fiction. But researchers have developed a new device that works in a completely different way to existing technology, neatly sidestepping some past issues and potentially helping to hide everyday objects under everyday conditions.

Metamaterials that cloak people and objects from radar, visible light or infrared are usually thick and heavy, but now engineers at the University of Wisconsin-Madison have developed an ultrathin, lightweight sheet that absorbs heat signatures and can even present false ones.

Researchers have developed a new technique to make metamaterials with nanoscale structures that can be tuned with strange optical properties. Using DNA-modified gold nanoparticles, the team could change the material's color, opening the door for new sensors or cloaking devices.

Researchers from TU Wien have developed a new process that allows light waves to pass right through a material by projecting a matching wave pattern onto it, actively camouflaging the target from view. The technique could be used as an invisibility cloak, and it might also work on sound waves.

Engineers at Iowa State University may have gotten one step closer to the ability to make objects invisible with the development of what they are calling a flexible, stretchable and tunable meta-skin that can suppress radar detection.

To combat the lower-frequency, directed anti-stealth radar-targeting systems being developed, researchers have developed a thin electronic material that may help hide aircraft from missile-targeting radar.

Scientists at UC Berkeley have developed a foldable, incredibly thin invisibility cloak that can wrap around microscopic objects of any shape and make them undetectable in the visible spectrum.

A new invisibility cloak developed at the Karlsruhe Institute of Technology (KIT) is reportedly able to hide cylindrical objects up to one inch in diameter, while relying only on common materials like polymers and acrylic paint.

Two scientists at the University of Rochester have taken invisibility cloaking back to basics. Their novel arrangement of four standard, off-the-shelf lenses keeps an object hidden (and the background undisturbed) as the viewer moves up to several degrees away from the optimal viewing angle.

Scientists at Karlsruhe Institute of Technology have developed a method of concealing objects from the sensation of touch that would finally meet the exacting standards of Hans Christian Andersen's fairy tale princess, who felt a single pea prodding her beneath 20 mattresses and 20 feather beds.

Engineers from Duke University have used metamaterials to create an acoustic cloak that makes it appear as if sound waves directed at it were being reflected off a flat surface, regardless of the direction the sound originated from or where the observer was located.

Sometimes everything happens at once. The new game in town is active invisibility cloaks (AIC), which use electronics and antennas to hide an object over a broad range of frequencies. They come with a set of strengths and limitations.