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Tuesday, 1 April 2014

Ever wondered lighting a flashlight powered by body heat ? This 16 years old did it !!!

Two years ago, Ann Makosinski was inspired by a friend in the Philippines who didn't have electricity – the girl told Ann she couldn't complete her homework and was failing in school. So she experimenting with Peltier tiles, which produce an electrical current when opposite sides are heated and cooled at the same time. She said she'd heard people described as "walking 100-watt lightbulbs," and became inspired to use body heat as an energy source. "We have so much energy just radiating out of us, and it's totally being wasted," she told ABC News. 
Ann spent months working on the project; her patent-pending design uses a transformer of her own creation. Incredibly, the project only took second place at her local science fair. Makosinski’s flashlight is hollow. The tiles are warmed on the outside, and cooled by the air inside.That generates enough power to maintain a steady beam of light for 20 minutes.

The 'hollow flashlight' – which Makosinski has defined as "ergonomic" and "thermodynamically efficient". Makosinski says temperature comes into play, because there needs to be a five-degree difference between the user's hand and the room's – or atmosphere's – ambient temperature. "They're these flat tiles," she told Larson, "and if your body heat runs on one side, and you cool the other side, it will produce electricity.

What Makosinski did was to leave out the power supply, and instead hook up a set of wires and a power transformer, and run the whole thing in reverse. She put the 'cool' side of these tiles against the outer shell of the flashlight handle, and the 'hot' side of the tiles against a hollow aluminum tube inside the handle. As the heat from the hand holding the flashlight warms the 'cool' side of the tile, the tile moves that heat to the other side, generating an electric current. When the heat reaches the other side, the room-temperature aluminum pipe draws the heat away, and this sets up a continuous current that runs through the transformer and makes the LEDs light up. As long as there's a temperature difference between the two sides of the tile, the electricity will flow and the greater the temperature difference, the brighter the flashlight will be.

"For this first project, I heated one side with a candle and cooled the other side, so there was a very large temperature differential. I noticed that the greater the temperature differential, between the hot and the cold sides, the more power was produced. "As humans, we radiate enough heat that's close to 100 watts' worth of lightbulbs. So I thought, 'Why not take advantage of that?' The flashlight just seemed like the best application."

If you hooked up one of the 'Peltier tiles' in this flashlight to a battery, one side of the tile would heat up and the other side would get cold (and it's always the same sides). This would eventually reach a point where it stopped, maintaining the same temperature difference between the two sides. If you cooled the 'hot' side of the tile or heated the 'cold' side of it (or both), the tile would draw more current from the battery to push more heat from the 'cold' side to the 'hot' side, to try to keep the same temperature difference.

She has filed a provisional patent application with the United States and Trademark Office. She may look into mass producing it and putting them into emergency kits etc. Or  take the technology itself and apply it to other areas, eg. medical devices. However, before I did any of that I would want to improve it a lot in its efficiency, design, etc.
Over the summer, the school got a message from someone offering her supplies to help improve her design.