The revolutionary wave disc generator combustion engine

The heart of the wave generator motor

The mid-term future for fuel efficient vehicles with useful range is likely a hybrid solution of electric motors powered by batteries, topped up by a fuel-burning generator. Dr. Norbert Müller at Michigan State, backed by $2.5 million from the US Government, aims to make that last part of the equation a much more compact and efficient proposition with a revolutionary new form of combustion engine.

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The culmination of years of research, the latest version is in the form of a spinning metal disc with precisely-calculated radial channels. Fuel/air mixture enters via the central hub and travels outwards. As the disc spins the channel exit becomes closed off causing a back-shock. Because the inlet port is now closed off to the channel this causes compression (like a piston) and the fuel/air mixture is then ignited. The expansion of the explosion powers the wheel, opening the channel once more to the inlet and outlet ports. The exhaust gas is ejected and fuel/air is sucked in to repeat the process - at very high speed naturally.

This elegant design does away with many of the moving parts and circulatory systems of conventional combustion engines that lower their fuel-use efficiency, typically 15%. Dr. Müller is obtaining efficiencies of 60% with the wave disc design and of course the weight of the engine is greatly reduced.

"Our goal is to enable hyper-efficient hybrid vehicles to meet consumer needs for a 500mile driving range, lower vehicle prices, full-size utility, improved highway performance and very low operating costs," says Müller. "The WDG (Wave Disc Generator) also can reduce carbon dioxide emissions by as much as 95% in comparison to modern internal combustion engine vehicles."

While the team's focus is very much on automotive use, for obvious reasons, there is clearly potential for the creation of very compact and efficient electricity generators that would sell in vast numbers across the world. For the moment however this all still in the research phase and we have to take the team's claims of potential emissions reduction on trust.

A "car-sized" 25 kW (33.5 hp) version of the working prototype is due by the end of the year with further funding required after February 2012. We hope Dr. Müller and his team get the money they need to bring this elegant solution to a pressing need to market as soon as possible.

New heat-regulating building material could cut building heating and cooling costs

A new heat-regulating material could be used in buildings to cut heating and cooling costs

Researchers at the Ningpo, China campus of the University of Nottingham (UNNC) have created a new heat-regulating material that could be used to cut the heating and cooling costs of buildings. The non-deformed storage phase change material (PCM) can be fixed so that it starts absorbing any excess heat above a pre-determined temperature and releasing stored heat when the ambient temperature drops below the set point. The researchers say the material can be manufactured in a variety of shapes and sizes, even small enough so that it can be sprayed as a microscopic film to surfaces in existing buildings.

The researchers at UNNC's Centre for Sustainable Energy Technologies say the novel material possesses a larger energy storage capacity with faster thermal response than existing materials and could be cheaply manufactured. The basic structure of the material has to be engineered for a specific temperature before it is used and the research team, led by Professor Jo Darkwa, who is Director of the Centre for Sustainable Energy Technologies, is now looking at creating material that can be used for both heating and cooling applications.

"The material won't make air-conditioners obsolete, because you still need an air conditioner to control humidity and air movement. This material purely reduces the amount of excessive heat energy in a room," said Professor Darkwa.

The material created in the lab looks like a circular tablet with the circumference of a large coin, but can be manufactured in various shapes and sizes so it can be applied anywhere, from walls and roofs to wallpaper, the researchers say. They believe it has the potential to save up to 35 percent of energy in a building and could also be used to enhance the efficiency of solar panels and LED lighting.

The scientists have already been awarded a patent application approval in China for the novel material, with applications in the pipeline in other countries. The UNNCis looking to develop the material further and commercialize it.

"The construction industry produces more carbon emissions than any other industry in the world -- even more than aviation. In China, the building sector is one of the highest energy consuming sectors, accounting for about 30 per cent of total energy usage and also a significant proportion of pollutant emissions. This material, if widely used, could make a major impact in the world's efforts to reduce carbon emission," said Professor Darkwa.

Graphene-based transparent touchscreens and solar panels a step closer

Postdoctoral researcher Yu Zhu with the graphene-based hybrid film on a flexible plastic substrate

Graphene promises to revolutionize electronics but we're still waiting for graphene-based technologies to hit the market. Rice University researchers have now created transparent, graphene-based electrodes that they say could be the "killer app" that finally puts graphene into the commercial spotlight. The graphene-based electrodes could be used to replace the increasingly expensive indium tin oxide (ITO) in touch-screen displays, photovoltaic solar cells and LED lighting.

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ITO is used as a transparent, conductive coating in virtually all flat-panel displays, including touch screens on smartphones and tablet computers, and is used in organic light-emitting diodes (OLEDs) and solar cells. With the increase in popularity of these products the element indium has become increasingly rare and therefore more expensive. It is also brittle, which rules it out for use in flexible displays and heightens the risk of the screen of your smartphone cracking when the device is dropped.

For these reasons, researchers have been looking for an electrically conductive ITO replacement that can be put on a flexible substrate such as plastic. Now the lab of Rice chemist James Tour has created thin films that could combine with other flexible, transparent electronic components and lead to computers that wrap around the wrist and solar cells that wrap around just about anything.

The Tour Lab's thin film combines a single-layer sheet of highly conductive graphene with a fine grid of metal nanowire. The researchers claim the material easily outperforms ITO and other competing materials, with better transparency and lower resistance to electric current.

"Other labs have looked at using pure graphene. It might work theoretically, but when you put it on a substrate, it doesn't have high enough conductivity at a high enough transparency. It has to be assisted in some way," says Tour.

Conversely, said postdoctoral researcher Yu Zhu, lead author of the new paper detailing the team's work, fine metal meshes show good conductivity, but gaps in the nanowires to keep them transparent make them unsuitable as stand-alone components in conductive electrodes.

But combining the materials works superbly, Zhu said. The metal grid strengthens the graphene, and the graphene fills all the empty spaces between the grid. The researchers found a grid of five-micron nanowires made of inexpensive, lightweight aluminum did not detract from the material's transparency.

"Five-micron grid lines are about a 10th the size of a human hair, and a human hair is hard to see," Tour said.

Tour said metal grids could be easily produced on a flexible substrate via standard techniques, including roll-to-roll and ink-jet printing. Techniques for making large sheets of graphene are also improving rapidly, he said; commercial labs have already developed a roll-to-roll graphene production technique.

"This material is ready to scale right now," he said.

Although tests showed the hybrid film's conductivity decreases by 20 to 30 percent with the initial 50 bends, the material then stabilizes and no significant variations were observed at up to 500 bending cycles. Tour said more rigorous bending testing will be left up to commercial users.

"I don't know how many times a person would roll up a computer," Tour added. "Maybe 1,000 times? Ten thousand times? It's hard to see how it would wear out in the lifetime you would normally keep a device," Tour said.

The film is also environmentally stable with test films exposed to the environment in the lab showing no signs of deterioration after a period of a year. Additionally, the use aluminum and carbon offers significant savings compared to the increasingly expensive ITO.

"Now that we know it works fine on flexible substrates, this brings the efficacy of graphene a step up to its potential utility," Tour said.

The Rice University team's paper, co-authored by graduate students Zhengzong Sun and Zheng Yan and former postdoctoral researcher Zhong Jin, appears in the online edition of ACS Nano.