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Updated Saturday, March 22, 2008 0:00 am TWN, By MAGGIE FOX, Reuters |
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Nanotech to make better conductorThe crushed material makes it possible to conduct electricity without conducting so much heat, solving a problem that has baffled engineers for 50 years. Writing in the journal Science, the teams at the Massachusetts Institute of Technology and Boston College said their method provides a cheap way to achieve a major increase in thermoelectric efficiency. “It conducts 40 percent less heat,” Boston College physicist Zhifeng Ren said in a telephone interview. “In order to achieve that 40 percent less heat conduction you need to have the grains smaller so that you have more blocks to the heat flow.” Smaller grains of the conducting material — in this case bismuth antimony telluride — scatter and redirect the heat, making a compound that can be used either for cooling or to generate electricity. “These thermoelectric materials are already used in many applications but this better material can have a bigger impact,” added Gang Chen, a professor of mechanical engineering at MIT who also worked on the study. The new material could have applications in solar energy, refrigeration, exhaust systems and even in more prosaic applications. “You can use this kind of cooling device for the thermoelectric cold car seat in luxury cars,” Ren said. “You can use it for picnic coolers. A lot of scientific instruments need confined spot cooling,” he said. “You can also use it for generating electricity. Anywhere you have a heat source like a car exhaust pipe, you can generate electricity from the heat and save gas.” A joint patent has been issued to Boston College and MIT on the technology and the schools have licensed it to Chen and Ren’s start-up company GMZ Energy. | |||||||||||||