Invisibility

Invisibility cloaks have been around in various forms since 2006, when the first cloak based on optical metamaterials was demonstrated. The design of cloaking devices has come a long way in the past seven years, as illustrated by a simple, yet highly effective, radar cloak developed by Duke University Professor Yaroslav Urzhumov, that can be made using a hobby-level 3D printer.  Read More

Recent years have seen much progress in the development of invisibility cloaks which bend light around an object so it can't be seen, but can the same principles be applied to ocean waves that are strong enough to smash steel and concrete? That's the aim of Reza Alam's underwater “invisibility cloak.” The assistant professor of mechanical engineering at the University of California, Berkeley, recently outlined how to use variations of density in ocean water to cloak floating objects from dangerous surface waves.  Read More

When we think of invisibility cloaks, probably the first things that come to mind are Harry Potter-like contraptions that allow people or large objects to instantly disappear. Scientists from the University of Maryland and nearby Towson University, however, today announced their development of something a little different – little being the key word. They have crammed 25,000 tiny “invisibility cloaks” onto a gold sheet, which itself only measures 25 millimeters per side. While the resulting biochip array may not allow any young wizards to vanish from sight, it could allow them to identify biological materials.  Read More

While “cloaking” technology may have once been limited exclusively to the realm of science fiction, regular Gizmag readers will know that it is now finding its way into real life – just within the past few years, scientists have demonstrated various experimental cloaking systems that prevent small objects from being seen, and in one case, from being heard. Such invisibility systems involve the use of metamaterials, which are man-made materials that exhibit optical qualities not found in nature. These are able to effectively bend light around an object, instead of allowing it to strike the object directly. Now, mathematicians from the University of Manchester are proposing technology based on the same principles, that would allow buildings to become “invisible” to earthquakes.  Read More

We’ve previously seen – or should that be “not seen” – invisibility cloaks in the laboratory that are able to render two-dimensional objects invisible to microwaves. Such feats relies on the use of metamaterials – man-made materials that exhibit optical properties not found in nature and have the ability to guide light around an object. Now researchers at the University of Texas at Austin (UT) claim to have brought invisibility cloaks that operate at visible light frequencies one step closer by cloaking a three-dimensional object standing in free space with the use of plasmonic metamaterials.  Read More

Many of the current experimental "invisibility cloaks" are based around the same idea - light coming from behind an object is curved around it and then continues on forward to a viewer. That person is in turn only able to see what's behind the object, and not the object itself. Scientists from Germany's Karlsruhe Institute of Technology have applied that same principle to sound waves, and created what could perhaps be described as a "silence cloak."  Read More

Although Klingon-style disappearing spaceships may not be in our neighborhood any time soon, the technology that could allow a spaceship to vanish from sight may be here now. Scientists from the University of Michigan have successfully made a three-dimensional etched silicon image of a tank appear as a featureless black void, that completely blended in with the backdrop surrounding it. The secret: good ol’ carbon nanotubes.  Read More

You have no doubt seen mirages on the distant surfaces of hot highways before, looking like pools of water shimmering on the asphalt. Such illusions are caused by hot air above the road, which refracts light waves coming down into it from the cooler air above – in other words, the supposed “water” is actually the sky, its image being bent toward you by the low-lying hot air. Well, scientists at the University of Texas at Dallas have put the same principle to work in the lab, and created an invisibility cloak that can be easily switched on and off.  Read More

Infrared imaging is used for a range of military applications - such as target acquisition, night vision, homing and tracking - which means that any vehicle with some kind of infrared “invisibility cloak” would hold significant advantages on the battlefield. BAE Systems has tested just such a technology that not only allows vehicles to blend into their surroundings, but can also let it mimic other vehicles or natural objects.  Read More