Fifteen Anne Makosinski from Victoria, British Columbia, Canada, presented his invention to the world - lights, powered by the heat of the human body - Hollow Flashlight. His invention of a girl created a contest for school science projects.
"We are surrounded by a lot of energy, which we did not even think to use for electrical power," - says Makosinski. Looking for a suitable topic for the project, she discovered the so-called Peltier effect - a natural phenomenon in which heat is absorbed or released during the passage of current in place junction of two different conductors.
"I used the Peltier elements and the effect of the temperature difference between the human hand and the air. I managed to create a lantern that shines brightly without batteries. This device is ergonomic, thermodynamically efficient, and for the production of five milliwatts of power it requires a difference of five degrees in temperature between the body and the environment "- says the inventor.
Prototyping Makosinski produced some calculations to see whether the palm of the heat to be an effective source of power for the flashlight on the basis of Peltier elements. If the human hand is capable of producing enough heat, it can be converted into electricity. And then the lamp will work without batteries or sources of kinetic energy, but only by body heat.
First Makosinski bought several Peltier elements and check whether you can use them to get to work the LED. As recognized by the inventor, with a capacity of no problems, the question was only how to obtain the required voltage. After reading many articles on the Internet, Makosinski realized that you can achieve good results, if slightly change the structure of the circuit.
"The final design of the lamp was: I Peltier elements mounted inside a hollow aluminum tube, which in turn is placed in the PVC tube with a small hole that allows air to circulate and cool the unit. As a result, the lantern shining a bright light when the temperature difference was only five degrees Celsius "- says Makosinski. Of the two prototypes, which it is constructed, it did not require any batteries - both worked on the palm of heat.
The cost of all materials that are needed to create two lanterns, was only $ 26. Investments were not in vain: Makosinski has already become one of the 15 finalists of the prestigious competition of scientific inventions Google Science Fair in the age group 15-16 years.
Incidentally, among the 15 global finalists are representatives from Russia. Lisa pine and Tina Kabir from Moscow fall into the category of 13-14 years. Students created LiTin device for measuring the density of liquids, bulk materials and solids, and body weight. Feature of the device, according to the jury, lies in its versatility. He was easy to use, and when you create it used readily available materials.