Cloaking

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

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

Last year researchers at Imperial College London proposed that along with being used to cloak physical objects metamaterials could also be used to cloak a singular event in time. A year later, researchers from Cornell University have demonstrated a working "temporal cloak" that is able to conceal a burst of light as if it had never occurred.  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

Take some light bending metamaterials, incorporate them into flexible fabric and you have yourself an invisibility cloak. That's the theory anyway, and it doesn't stop at hiding objects. Building on the optical invisibility research of Professor Sir John Pendry, researchers from Imperial College, London, have now proposed that similar metamaterials could be used to conceal entire events – get ready for the "Spacetime cloak".  Read More

We’ve covered a few different research efforts looking to develop “invisibility cloak” technology on Gizmag, including 3D metamaterials that negatively refract visible and near-infrared light and U-shaped “nano-rings” that manipulate light. The latest news sure to get Harry Potter fans excited comes out of Michigan Technical University where Elena Semouchkina, an associate professor of electrical and computer engineering, has found ways to use magnetic resonance to capture rays of visible light and route them around objects, rendering them invisible to the human eye.  Read More

Over the last few years we’ve covered the development of “invisibility cloaks” using metamaterials – man-made structured composite materials exhibiting optical properties not found in nature that can guide light to achieve cloaking and other optical effects. In 2006, scientists at Duke University demonstrated in the laboratory that an object made of metamaterials can be partially invisible to particular wavelengths of light - not visible light, but rather microwaves. A few groups have even managed to achieve a microscopically-sized carpet-cloak. Now researchers have developed software that can show what such a cloaked object will actually look like.  Read More

Mathematicians at the University of Utah have recently announced they have elaborated an innovative way to shield two-dimensional objects from all types of waves, from electromagnetic to those caused by natural events like earthquakes and tsunamis, leading the way to a completely new approach to achieving invisibility.  Read More