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Researchers used carbon nanotubes for breakthrough

The storage and generation of electricity is a hotbed of scientific study around the world. New and improved methods of storing electricity have a myriad of potential uses from phones and laptops that run longer to new electric vehicles with much greater driving range.

At the center of much of the research in the storage and generation of power in batteries and other devices are carbon nanotubes. The carbon nanotube has been studied for decades and new advances over the last few years have made the nanotubes easier to produce and have offered breakthroughs in the use of carbon nanotubes. Scientists at Rice University made a breakthrough in carbon nanotube processing in November of 2009 that uses processes similar to those that have been employed in the plastics industry to make the production of carbon nanotubes in bulk much easier.

Researchers in late 2009 also found that defective carbon nanotubes are more efficient at storing energy than carbon nanotubes that are uniform in size. In February 2010, Bayer announced that it was opening the world's largest carbon nanotube production facility to develop carbon nanotubes dubbed "Baytubes" using multi-wall carbon nanotube technology. The facility is expected to produce about 200 metric tons of nanotubes each year.

Now, a team of researchers at MIT have announced that they have made a new breakthrough for producing electricity with carbon nanotubes. The discovery may one day lead to a myriad of new devices such as sensors the size of dust that can be dispersed in air to monitor the environment or the tech might lead to implantable devices that produce their own power. The researchers discovered a phenomenon that was previously unknown that produces powerful waved of energy that shoots though carbon nanotubes, producing electricity.

The team of researchers called the phenomenon "thermopower waves." MIT's Michael Strano, the Charles and Hilda Roddey Professor of Chemical Engineering, and senior author of the paper reporting the findings said, "[Thermopower waves] opens up a new area of energy research, which is rare."

The thermal wave is a moving pulse of heat that travels along the microscopic carbon nanotubes and drives electrons along with it creating an electrical current. The team coated carbon nanotubes with a highly reactive fuel that produces heat as it decomposes. The fuel was ignited at one end of the nanotube with a laser beam or high-voltage spark.

The resulting ignition created a fast moving thermal wave that travels about 10,000 times faster than the normal speed of the reaction according to the team. The temperature of the ring of heat reaches about 3,000 kelvins, pushing electrons along the tube creating a substantial electrical current. Strano says that the combustion waves have been mathematically studied for more than a hundred years, but he claims to be the first to predict that the combustion waves could be guided by a nanotube or nanowire and push an electrical current along the wire.

Strano says, "[In early experiments] lo and behold, we were really surprised by the size of the resulting voltage peak." He continued saying, "There's something else happening here. We call it electron entrainment since part of the current appears to scale with wave velocity.

Strano says that since the discovery is so new it is hard to predict how it could be used in practical application. The team plans to conduct more research using different kinds of reactive materials for the fuel coating and the team suspects that by using other materials for the coating the front of the wave could oscillate to produce an alternating current. The team points out that most of the power generated with the new method is given off as light and heat and work is ongoing to make the process more efficient.



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RE: toner
By NicodemusMM on 3/8/2010 6:08:42 PM , Rating: 3
A good example of emotion over logic would be deriding someone for simply referencing 9/11 in order to make a perfectly valid point. Should the loss of life make it so touchy a subject that we can't even learn from it??

"Those who cannot learn from history (even recent history), are doomed to repeat it."


"When an individual makes a copy of a song for himself, I suppose we can say he stole a song." -- Sony BMG attorney Jennifer Pariser














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