15-year-old girl has developed a flashlight, powered by the heat of the hands

The project was proposed by Canadian girl Anna Makosinski (Ann Makosinski) for the Google Science Fair contest. The energy for the flashlight, strictly speaking, is taken not from the warmth of the hands, but from the temperature difference: the girl used the Seebeck effect discovered in the nineteenth century.
Surprisingly, the heat generated by the skin of the palm 57 mW was enough to be a source for a thermoelectric generator (on Peltier elements) at an ambient temperature different from that of the hand by 5 degrees, and the resulting flashlight is able to produce 5 FC light (about 55 lux) ).

Full description of the project you can read here .
When Anna wins the competition and gets her $ 50,000 from Google, she will probably think about how to start mass production of flashlights: her pilot model was worth $ 26.