Flashlight Powered By The Heat of Your Hand

Ann Makosinski, a 15-year old Victoria student created a hollow flashlight that runs solely on the heat of the human hand. It’s based on fact that body radiates 5 mV of heat per square centimeter and only 0,5 mV is needed to produce the light. Her project has been picked for the finals of the Google Science Fair. She will visit Google campus in Mountain View, California in September for the prize ceremony, Google announced on Thursday. Winners will be chosen in three age categories, and one will receive the grand prize, which includes a $50,000 scholarship from Google and a trip to the Galapagos Islands.

Makosinski has been submitting projects to science fairs since Grade 6, and has been particularly interested in alternative energy.”I’m really interested in harvesting surplus energy, energy that surrounds but we never really use,” Makosinski said in an interview Thursday. While researching different forms of alternative energy a few years ago, she learned about devices called Peltier tiles that produce electricity when heated on one side and cooled on the other. 

She experimented with such tiles for her Grade 7 science fair project and thought of them again as a way to potentially capture the thermal energy produced by the human body. Makosinski did some calculations to see if the amount of energy produced by warmth from a person’s hand was theoretically sufficient to power an LED bright enough to use in a flashlight, and she found it was more than enough.

She bought Peltier tiles on eBay and tested them to see if they could produce sufficient power to light an LED. It turned out the power was more than enough, but the tiles generated only a fraction of the voltage needed. Further research suggested that if she made some changes to the design of the circuit, transformers could be used to boost the voltage.

Makosinski admitted there were points in the experiment when she thought it would never work, but said “You just kind of have to keep going.” She spent months doing research on the internet, experimented with different circuits and even built her own transformers, which still didn’t provide enough voltage.” This took quite awhile ’cause I had to do it during the school year as well and I had homework, plays, whatever that I was also doing,” she recalled. In the end, she came across an article on the web about energy harvesting that suggested an affordable circuit that would provide the voltage she needed when used with a recommended transformer, she said in an online report submitted to Google.

Finally, the circuit worked.