Ann Makosinski, from British Columbia, has invented a flashlight that produces light just by using the warmth of your hands. The 15-yr old Canadian has invented a 'Hollow Flashlight' that works via the thermoelectric effect. The thermoelectric effect is where a change in temperature can lead to electric voltage and vice-versa.
Ann Makosinski measured that about 57 milliwatts on heat can be generated from the heat of your palm and she needed about half a milliwatt for an LED light. Next, she used Peltier tiles to generate electricity, and other components to make the current usable for a normal LED flashlight. Finally she added this to a hollow aluminum tube and with a little tweaking of voltages and components she was able to invent the flashlight.
The light generated from the flashlight is modest but works if you need to find your keys or other small tasks. The flashlight works for about half an hour at a temperature of 10 degrees Celsius and can last longer or shorter varying on temperature differences.
Makosinski told NBC News, "I'm sure we've all had that annoying experience when we desperately need a flashlight, we find one, and the batteries are out. Imagine how much money we would save and the amount of toxins leached into the soil etc., reduced if we didn't use any batteries in flashlights!"
Makosinski has also submitted her invention at the Google Science Fair and is one of the 15 finalists. She will be visiting the Google headquarters in California for the final judging event. Google will choose one winner each out of three age groups and the final winner will receive a grand prize of $50,000 and a trip to the Galapagos Islands.