Metamaterials that bend light backwards bring invisibility closer

Aug 12th, 2008 | Filed under: Electronics | 0 Comments

Scientists at the University of California, Berkeley, have for the first time engineered 3D materials that can reverse the natural direction of visible and near-infrared light, a development that could help form the basis for higher resolution optical imaging, nanocircuits for high-powered computers, and, to the delight of science-fiction and fantasy buffs, cloaking devices that could render objects invisible to the human eye.

Two breakthroughs in the development of metamaterials – composite materials with extraordinary capabilities to bend electromagnetic waves have been reported.

Applications for a metamaterial entail altering how light normally behaves. In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock. For optical microscopes to discern individual, living viruses or DNA molecules, the resolution of the microscope must be smaller than the wavelength of light.

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Stretchy material could lead to flexible electronics

Aug 11th, 2008 | Filed under: Design, Electronics | 0 Comments

Scientists from the University of Tokyo have developed a stretchy, rubbery material which is able to conduct electricity.

When the material, which comprises single wall carbon nanotubes, elastic resin and an ionic liquid, is attached to a grid of tiny transistors, it cab be stretched up to 2.34 times its original size, without adverse effects to the conductivity. Later it reverts to its original form.

A similar material was developed in 2005, but was only able to stretch 1.25 longer than its original size, and its conductivity limited to 10S/cm. The newly developed material has a conductivity of 57S/cm.

According to a paper published by the scientists working on the project, the material could be used to create flexible electronics, and there have been suggestions it could be used on the joints of a robot’s arm.

A smoother approach to tile quality

Aug 7th, 2008 | Filed under: Design | 0 Comments

Surface defects in ceramic tiles, invisible to the naked eye, could be automatically detected by a new system being developed at the University of the West of England (UWE).

The system would detect imperfections such as pinholes, crazing, rough or dull glazes, even on tiles with a texture or relief pattern, saving the industry time and money and reducing wastage.

Based on photometric stereo technology, a demonstration model is being developed at UWE’s Machine Laboratories, in collaboration with the University of Bath, and Fima Surface Inspection.

Professor Melvyn Smith, director of the Machine Vision Lab, said: “This three-year project will lead to significant advances in automating inspection of ceramic tiles. It could also have applications in other industries, where the quality of the surface is paramount, such as metals or shiny plastic components. It builds on our existing expertise in photometric stereo, and will be able to capture surface topography detail at extremely high resolution, at pixel level.”

TE material turns waste heat into electricity

Jul 28th, 2008 | Filed under: Automotive | 0 Comments

Researchers at Ohio State University have invented a new material designed to make cars more efficient by converting heat wasted through engine exhausts into electricity.

Scientists rate the efficiency of thermoelectric (TE) materials based on how much heat they can convert into electricity at a given temperature. To maximise the amount of electricity produced by a TE material, engineers would normally try to limit the amount of heat that can pass through it without being captures and converted to electricity. So the typical strategy for making a good TE material is to lower its thermal conductivity.

Project leader, Joesph Heremans took a different approach, focussing on how to convert the maximum amount of heat that was naturally trapped in the TE material. To do this he took embraced some new ideas in quantum mechanics.

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Light powered plastic motor

Jul 24th, 2008 | Filed under: Design | 0 Comments

A plastic motor powered completely by light has been developed by the Tokyo Institute of Technology.

Unlike solar-powered motors that use photovoltaic cells to convert light to electric power (this also requires wires and batteries to deliver and store the power), this motor converts light directly into mechanical energy using a belt made of a special elastomer, with a molecular structure that expands or contracts when illuminated, depending on the wavelength of light.

Tomiki Ikeda, leader of the research team at Tokyo Institute of Technology, discovered a plastic compound containing azobenzene would contract when exposed to ultraviolet light, and resume its original shape when exposed to visible light.

Since this discovery in 2003, Ikeda and his team have been working on improving the shape-shifting properties of the material, and have been looking at ways to incorporate the material in a motor to convert light directly into motion.

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Taking curves into consideration

Jul 16th, 2008 | Filed under: Aerospace, Design | 0 Comments

A new manufacturing process developed by GKN Aerospace, makes it possible to create titanium structures from compound curves.

GKN Aerospace’s new ‘Delta pressure forming’ technique builds on the drape creep forming technique previously used by the company to create flat panels of titanium honeycomb sandwich. The new process uses an improved version of this drape creep forming process that substitutes the static weights for a roller system, to produce a cylindrical honeycomb barrel.

The cylindrical barrel is inflated into a die to create the required compound curvature. The operation is conducted in a vacuum furnace at temperatures exceeding 1500?F and the inflation pressure is provided by inert argon gas. Sophisticated forming analyses and special tooling features ensure the honeycomb core and the face sheets are not damaged during the process.

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Earliest genetic material is extraterrestrial

Jul 3rd, 2008 | Filed under: Electronics | 0 Comments

An important component of early genetic material found in meteorite fragments is extraterrestrial in origin, according to scientists.

The scientists, from Europe and the USA, say that their research, published in the journal Earth and Planetary Science Letters, provides evidence that life’s raw materials came from sources beyond the Earth.

The materials they have found include the molecules uracil and xanthine, which are precursors to the molecules that make up DNA and RNA, and are known as nucleobases.

The team discovered the molecules in rock fragments of the Murchison meteorite, which crashed in Australia in 1969. They tested the meteorite material to determine whether the molecules came from the solar system or were a result of contamination when the meteorite landed on Earth. Analysis revealed the nucleobases contain a heavy form of carbon which could only have been formed in space. Materials formed o

Bio-coating enhances bone growth

Jul 2nd, 2008 | Filed under: Bio Tech | 0 Comments

A biologically-inspired material that is said to enhance tissue healing, improve bone growth around an implant and strengthen the attachment and integration of the implant to the bone, has been developed by researchers at the Georgia Institute of Technology.

Andrés Garcia, Georgia Tech, explained: “We designed a coating that specifically communicates with cells, and we’re telling the cells to grow bone around the implant.”

He continued: “Our coating consists of a high density of polymer strands, akin to the bristles on a toothbrush, which we can then modify to present our bio-inspired, bioactive protein.”

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Sensors detect and distinguish explosives

May 15th, 2008 | Filed under: Electronics, Military | 0 Comments

Chemists at the University of Massachusetts Amherst, have developed complex molecules containing zinc for use in portable sensors that quickly and reliably detect the presence of plastic explosives.

Sensors containing the zinc complexes are the first devices that allow the user to identify which type of explosive is present, since each metal complex has a unique response to explosives and explosive mimics.

Commenting, Michael Knapp, an assistant professor of chemistry at the University, said: “This is a big improvement over existing sensors based on polymers, since the metal complexes can discriminate between closely related explosives compounds.

“This ability is a real advantage for airport security personnel and law enforcement officials, who need to quickly detect and identify what type of explosives they are dealing with.”

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