Connect with us

Hi, what are you looking for?


Clean Power

High School Girl Invents Flashlight Powered By Body Heat

I remember when I powered a small electric motor with heat (and a good amount of it) using a thermoelectric module. However, I had a hard time achieving more than 1 volt. A 15-year-old girl in tenth grade from Victoria, British Columbia, Canada recently got around this problem using a circuit that she discovered on the internet. She was able to power a flashlight/torch that produced 5 lumens of light per square foot (5 foot candles) using only heat from the human hand, which could be useful.

The high efficiency of LEDs makes impressive technologies such as these possible! LED efficiency can now exceed 120 lumens per watt (not the same as lumens/square foot).

The parts required to construct the flashlight cost only $26 and doesn’t need batteries or any complex mechanical systems to generate electricity.

“The final design included mounting the Peltiers on a hollow aluminum tube which was inserted in a larger PVC pipe with an opening that allowed ambient air to cool the tube. The palm wrapped around a cutout in the PVC pipe and warmed the tiles. The result was a bright light at 5 degree Celcius [sic] of Peltier differential. The flashlight worked!”

“Using four Peltier tiles and the temperature difference between the palm of the hand and ambient air, ” she said in her project statement, “I designed a flashlight that provides bright light without batteries or moving parts. My design is ergonomic, thermodynamically efficient, and only needs a five degree temperature difference to work and produce up to 5.4 mW at 5 foot candles of brightness.”

This flashlight landed her the position of finalist at the Google Science Fair. If she wins, she would receive a $50,000 scholarship and a trip to the Galapagos Islands.

The award ceremony is to commence in September. Winners will be chosen in the age categories: 13-14, 15-16, 17-18.

Appreciate CleanTechnica’s originality and cleantech news coverage? Consider becoming a CleanTechnica Member, Supporter, Technician, or Ambassador — or a patron on Patreon.

Don't want to miss a cleantech story? Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News!

Have a tip for CleanTechnica, want to advertise, or want to suggest a guest for our CleanTech Talk podcast? Contact us here.
Written By

writes on CleanTechnica, Gas2, Kleef&Co, and Green Building Elements. He has a keen interest in physics-intensive topics such as electricity generation, refrigeration and air conditioning technology, energy storage, and geography. His website is:


You May Also Like


The city of Amarillo, Texas, is polishing its green cred with new, mobile kinetic energy storage technology from the firm Ecolution Power Company

Autonomous Vehicles

A few days before the Q1 2021 Tesla Earnings Call, CEO Elon Musk touched upon the idea of Tesla as a leader in artificial...

Climate Change

Michael E. Mann and other scientists say climate deniers have stopped attacking global warming but have started challenging green policies in new ways.

Autonomous Vehicles

Wowza — that’s a top-tier troll to start the weekend. This autonomous driving space is getting especially saucy in 2021. There have been hot...

Copyright © 2022 CleanTechnica. The content produced by this site is for entertainment purposes only. Opinions and comments published on this site may not be sanctioned by and do not necessarily represent the views of CleanTechnica, its owners, sponsors, affiliates, or subsidiaries.