A bright idea: Flashlight powered by body heat
New Delhi, June 29: She is no scientist but has interest in alternative sources of energy. Canadian student Ann Makosinski has invented a flashlight that is powered by body heat.
That is right. You do not need batteries to run this flashlight. The flashlight design puts Ann with fourteen finalists who will be going to the Google Campus in Mountain View California to compete for the grand prize of $50,000.
Ann calls her torch a "hollow flashlight" and it can be powered by the heat of a user's hand. With abiding interest in alternative energy sources, Ann found that Peltier tiles can produce energy when they are heated on one side and cooled on the other. She thought of them as a way to potentially capture the thermal energy produced by the human body.
Her calculations convinced her that the amount of energy produced by the warmth of a person's hand was more than enough energy to power a LED flashlight.
She bought Peltier tiles from Ebay but the tiles generated only a fraction of the voltage needed. She made some changes to the design of the circuit.
It was hopeless situation till she came across an article on the web about energy harvesting and an affordable circuit that would provide the voltage she needed when used with a recommended transformer. This worked.
The flashlight is made up of an aluminum tube to transfer the cooler temperatures of the air to one side of the Peltier tiles and a PVC tube with an opening to allow a person's hand to come in contact with the other side of the Peltier tiles to transfer body heat.
All these materials cost a total of around $26, and if it were to be mass produced Ann says it can be manufactured and sold for a much lower price.
Ann Makosinski is a Grade 10 student at St. Michaels University School in Victoria, British Columbia, Canada.