Using Peltier tiles and the temperature difference between the palm of the hand and ambient air, Ann Makosinski designed a flashlight that provides bright light without batteries or moving parts.
In 2013, a high school junior in Canada invented a flashlight that only needs the warmth of the hand to turn on. While thinking of a way to harvest untapped energy, she was inspired to make the flashlight. She realized that the warmth generated by the human body was an overlooked energy source.
Her project objective was to create a flashlight that ran solely off the heat of the hand. That objective was accomplished when she discovered Peltier tiles, which produce electricity when one side of the tile is heated and the other is cooled.
Makosinski realized she could use these tiles to create energy for her flashlight if she left the device hollow.
Holding the flashlight on the outside would cause the tiles to heat up on one side while the ambient air would cool down the tile on the inside of the flashlight.
The power created by the tiles was enough to power an LED light, but it did not create enough voltage. To troubleshoot that issue she created a circuit that would allow for transformers, upping the voltage. It worked! The flashlight does have one issue: it works better in colder temperatures since the inside is better able to cool down comparative to the person’s body heat. Apparently, the light can last for about 20 minutes.
All in all, the flashlight cost her $26 dollars to make, which is a little pricier than most flashlights but understandable considering it eliminates having to keep buying new batteries. And she thinks that if her flashlight were mass produced, she could get the price down to even cheaper.
In September 2013, Makosinski was one of the three winners of the Google Science Fair in Mountain View, California, receiving a $50,000 scholarship and a trip to the Galapagos Islands.