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— Electronics

Power-harvesting device converts microwave signals into electricity

Joining the ranks of devices designed to harvest energy from ambient electromagnetic radiation comes an electrical circuit from researchers at Duke University that can be tuned to capture microwave energy from various sources, including satellite, sound or Wi-Fi signals. The researchers say the device converts otherwise lost energy into direct current voltage with efficiencies similar to that of current solar cells. Read More
— Architecture

Novel windows block out noise but let in fresh air

There are few things better than lazing around the house on a warm summer day, whose fragrant zephyrs speak of spicy isles and heaven-breathing groves.* At least, until the neighbors start their leaf-blowers and the city needs to tear up the sidewalks. Noise pollution is one of the scourges of urban and suburban life, which can drown out nature's melodies to cause annoyance, stress, and hearing loss. Now, however, a team of South Korean engineers has invented a remarkable window that lets air in while keeping a great deal of noise out. Read More
— Science

Metamaterials breakthrough could lead to the first wide-spectrum optical invisibility cloak

To make a Harry Potter-style invisibility cloak requires that the materials from which it is made have a negative refractive index over all optical wavelengths, from red to violet. However, the artificially-structured optical materials from which cloaks are made thus far have been restricted to a very narrow range of optical wavelengths, limiting their ability to cloak over a range of colors. That obstacle to progress ends now, as a group of Stanford optical engineers at Stanford has succeeded in designing a broadband metamaterial that exhibits a negative refractive index over nearly the entire rainbow. Read More
— Science

MIT produces new metamaterial that acts as a lens for radio waves

We expect the world to be predictable. Water flows downhill, fire burns and lenses bend light in a particular way. That worldview took a jolt as Isaac Ehrenberg, an MIT graduate student in mechanical engineering, developed a three-dimensional, lightweight metamaterial lens that focuses radio waves with extreme precision. That may not seem too disturbing, but the lens is concave and works in exactly the opposite manner of how such a lens should. Read More
— Science

Vibration "invisibility cloak" could protect buildings from earthquakes

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
— Science

Researchers cloak free-standing 3D object using plasmonic metamaterials

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
— Good Thinking Feature

2011: A year in technology

We cast a wide net over all types of new and emerging technologies here at - some save us time, some keep us connected, some help us stay healthy and some are just plain fun, but at the core of what we cover are those discoveries and innovations which have the potential to impact the fortunes of the human race as a whole and make a difference to the future of our planet. So with the calender having rolled over into another year, it's an ideal time to take a look back at some of the most significant and far-reaching breakthroughs that we saw during 2011. Read More
— Science

Proposed 'fluid flow cloak' might greatly reduce ships' hydrodynamic drag

North Carolina’s Duke University has been grabbing some headlines over the past few years, due to research carried out there involving the use of metamaterials for creating functioning invisibility cloaks. Just this month, Duke researchers announced that they had developed another such material that could be used to manipulate the frequency and direction of light at will, for use in optical switching. Now, Duke’s Prof. Yaroslav Urzhumov has proposed that metamaterials could also be used to drastically reduce the drag on ships’ hulls, “by tricking the surrounding water into staying still.” Read More