The Thermo Life generator is 9.3 millimeters in diameter and 1.4 millimeters high, about half the size of a penny and within the size range of 1.55-volt watch batteries. The company has packed 5,074 thermocouples (electricity-producing circuits) into the generator, and the device provides a relatively high voltage from a smaller temperature difference: At a difference of 5 degrees Celsius, the generator produces 3.1 volts at 36 microamps, yielding 110 microwatts of electrical power.
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