Flashlight Powered By Body Heat - No Batteries Needed!

Google Science Fair 2013 is home to very innovative projects developed by young, high-school students from over 200 countries. One of the interesting projects that got into the final rounds of the Google Science Fair is a 'Flashlight Powered By Body Heat', developed by a 15 year old school student Ann Makosinski. We've a video and demonstration of the project and we're quite sure that it's more interesting that what you could make when you were 15.


The flashlight works on the thermoelectric effect - that is direct conversion of temperature difference into electricity. A thermoelectric device creates voltage difference between the two sides of it at different temperatures. Ann put up aluminium tiles on the surface of a hollow pipe and the air flowing through it allows to maintain the temperature difference by keeping the other side cool. When the user holds the flashlight, the body heat causes the metallic strip to have higher temperature than the one with aluminium strips. This temperature difference is turned into electricity to power the LED flashlight by the thermoelectric device.

Ann could make the device under just $25 and believes that if the device is mass-produced, the cost would come down significantly. Check out Ann Makosinski explaining her project and how she put simple science technique to some creative use.