MadSci Network: Engineering |
The answer is yes. The device is called a "thermoelectric module." It uses something called the "Peltier effect." See this website: http://www.aoc- cooler.com/PELTIER-EFFECT.htm Now the Peltier effect takes electric current and makes a temperature difference. What you want is a temperature difference to make an electric current. Guess what: The thermoelectric module works both ways. When the temperature difference makes a current, the new name for the phenomenon is called the "Seebeck effect." The thermoelectric module uses doped semiconductors to perform its energy transformation. Both effects were discovered before semiconductors became common. At the small temperature differences available for everyday use, semiconductors do it better than thermocouples, on which these effects were discovered. A thermocouple is an electrical connection of two dissimilar metals. Heat the junction, it produces a voltage difference. Pass a current through it, it creates a temperature difference. Use of metallic thermocouples to produce electricity for power is not common, although it is for temperature measurement. But you do it where you have no choice. Space missions far from the sun use a "thermopile" -- series- connected thermocouples, half exposed to the near absolute zero of space, and half exposed to radioactively-decaying (hot!) plutonium. This great temperature difference generates considerable, long-lasting power (can't use batteries or solar cells) on 20-year missions, and is what powered the apparatus that gave us all those magnificent images from the Voyager missions. Thermoelectricity is a study all in itself. I hope I've given you a start in learning about it. Larry Skarin
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