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Metamaterials


— Science

Researchers overcome size hurdle in quest for invisibility cloak

Efforts to create a working "invisibility cloak" have generally involved the use of artificial materials with a negative refractive index known as metamaterials. Another promising technique involves the use of a natural crystal called calcite that boasts an optical property known as birefringence, or double-refraction. While both methods have proven successful in rendering very small objects invisible in specific wavelengths of light by bending and channeling light around them, both techniques require the "cloak" to be orders of magnitude larger than the object being concealed. Researchers are now reporting progress in overcoming this size limitation using a technology known as a "carpet cloak." Read More
— Science

'Spacetime Cloak' could conceal events

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
— Science

Flexible metamaterials the key to a working invisibility cloak?

Scottish researchers are reporting a "practical breakthrough" that could lead to the development of that most sought after of wardrobe items – the invisibility cloak. The concept of the invisibility cloak (not pictured) is based around harnessing the unique electromagnetic wave-bending properties of metamaterials, but this poses problems when it comes to creating flexible surfaces suitable for applications like clothing and contact superlenses for visual prostheses... problems which the new material design known as "Metaflex" hopes to address. Read More
— Good Thinking

New tech allows 'memory materials' to store multiple memorized shapes

They’re known as smart materials, memory materials or shape memory alloys, but it all boils down to the same thing: materials that hold one shape, but then take on another at a certain temperature. Such substances have been around for decades, but now researchers at Canada’s University of Waterloo have taken them to a new level. Using a patent-pending process, they can embed multiple shape memories in one object – in other words, while memory materials can presently take on only two shapes, going from one to the other at just one temperature, using the new process they could take on several shapes at several temperatures. The Multiple Memory Material Technology (MMMT) is said to work with virtually any memory material. Read More
— Science

Researchers working on an invisibility cloak made of glass

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
— Science

Tiny light mill could have big applications in nanotech

OK, first of all, what’s a light mill? It’s a simple rotary motor consisting of four flat vanes mounted to a central axis, which spins when subjected to light. Light mills have been around since 1873, mostly just as novelty items, and have pretty much always been at least a few inches tall. Less than a week ago, however, scientists at California’s Lawrence Berkeley National Laboratory announced the creation of a light mill just 100 nanometers in size. Unlike its bigger brothers, this tiny device might actually have some very practical applications. Read More
— Science

Chinese scientists create mini 'black hole'

Researchers at Southeast University in Nanjing, China have created a device that traps and absorbs electromagnetic waves coming from all directions, spiraling them inwards without any reflections, essentially creating an electromagnetic black hole. Qiang Cheng and Tie Jun Cui’s “omnidirectional electromagnetic absorber” draws in microwaves coming from any direction by spiraling radiation inwards, and converting its energy into heat. They plan on developing a device that can absorb visible light next. Read More
— Science

New metamaterial could lead to more efficient solar cells

Metamaterials are manmade substances designed to do some very weird things that natural materials don’t. The path of a beam of light through a natural material like glass is predictable, but scientists from the California Institute of Technology (Caltech) have engineered an optical material that bends light in the wrong direction. This new negative-index metamaterial (NIM) could have several valuable uses including invisibility cloaking, superlensing (imaging nano-scale objects using visible light) and improved light collection in solar cells. Read More
— Science

What invisible objects will actually look like

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
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