The next time you go camping, don't worry about batteries or an outlet to power your flashlight. If you have a model designed by teenager Ann Makosinski, you can light your way with your own body heat.

When 15-year-old Ann, a high school junior from Victoria, British Columbia, tried to come up with a project for her school's science fair, she decided she wanted to focus on a way to utilize unused energy in the environment — such as that generated by a human's own body heat.

In her research, Ann learned about Peltier tiles. Peltier devices — devices that produce electricity when one side of the tile is heated while the other side is cooled. What better way to generate power? And what better outlet for Ann's device than a flashlight?

After reworking the voltage and circuitry, Ann was able to create a light powered only by her own body heat. Next, she figured out how to use her idea to power a flashlight. Using a simple flashlight, the STEM-savvy teen cut away the plastic exterior so that the flashlight user's hand would come in direct contact with the built-in Peltier tiles. And just like that — she had light!

Ann's flashlight lasts for only about 20 minutes at a time, and it works better in colder temps as creates a larger temperature difference between the user's hand and the outside air. But for a preliminary model, it certainly make for a solid jumping off point for future designs. And it's earned her an invitation — along with 15 other science fair winners — to travel to Mountain View, Calif., this September for the Google Science Fair.

Check out Ann explaining her design in the video below:

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Source: ExtremeTech
Teen wows science fair with body-heat powered flashlight
Watch as 15-year-old Ann Makosinski explains how she figured out the voltage and circuitry necessary to facilitate her design.