The battery-powered flashlight was a huge improvement on the candle, and the hand-crank flashlight was a big upgrade from that. But who wants to look for the source of weird sounds in a dark basement with a flashlight that requires both hands for constant cranking? Not Ann Makosinski, for one.
Makosinski is only 15 years-old, a 10th grade student at St. Michaels University School in Victoria, Canada. But don’t let her lack of life experience fool you. The teen recently demonstrated a hollow flashlight concept that’s powered by nothing but the heat from a user’s hand–an invention that earned her a spot as one of 15 finalists in Google’s online science fair, beating out thousands of other students from more than 120 countries.
Makosinski has been fascinated by science from a young age, an interest that compelled her to enter projects into science fairs since the 6th grade. A few years ago, her personal investigation of alternative energy sources led her to discover Peltier tiles, devices that produce electricity when heated on one side and cooled on the other.
It occurred to Makosinski that such technology could be particularly useful in harvesting energy from the human body, which produces heat naturally, and thus the idea for the thermoelectric flashlight was born.
The teen bought Peltier tiles on eBay, and began the experimental phase. While the tiles created more than enough power to light an LED flashlight, the voltage was insufficient. After months of tinkering with different circuits and even building her own transformers, she discovered the type of circuit that was missing.
The result was two different versions of a body heat-powered flashlight. CBC News reports:
- An aluminum tube, obtained from a mechanical shop at the University of Victoria, where her father works as a laboratory manager. The aluminum was used to transfer the cooler temperatures of the air to one side of the Peltier tiles.
- A PVC tube from Home Depot used to house the aluminum tube, with an opening cut in it to allow a person’s hand to come in contact with the other side of the Peltier tiles.
In all, the materials for each flashlight cost about $26, but Makosinski says that mass production could create them for much less.