It is a norm to recharge your mobile or palmtop or iPod batteries so that you can have Icontinual usage without any power failure interruption. However, you may have a problem to search for a power socket before you can start recharging. How would it be if I suggest that you recharge it with your own body heat? Sound impossible. It may come true in the near future as scientists at the Fraunhofer Institute for Integrated Circuits in Erlangen, Germany, have developed new circuits that can harness electricity from body heat.

This is done based on the principle of thermoelectric generators (TEG) made from semiconductor elements.The temperature difference between a hot and a cold environment would cause the TEGs to produce electrical energy. However, it requires a difference of several tens of degrees to generate enough power. Normally, the temperature difference of the human body's surface with the environment is only a few degrees.

This little difference can cause a conventional TEG delivers roughly 250 millivolts of electricity, while electronic devices require at least one or two volts to operate. Peter Spies, electrical engineer and group manager at the institute, together with his team of engineers, have incorporated a component into the circuit called the charge pump. The pump temporarily stores the incoming millivolts until they reach 1.8 volts. Then an internal transistor turns on and delivers the voltage to a component that can transfer the electricity to an electrical appliance. However, such appliances must be reinvented to able to operate with low voltage of electricity.

Another way to work around the problem of low voltage is to create new circuits that can operate on 200 millivolts. With such innovation, the scientists can build entire electronic systems that do not require an internal battery, but draw the energy from the body heat alone. It is possible as circuits that are “excited” at 50 millivolts already exist. Spies believes that in the future, when further improvements have been made to the switching systems, a temperature difference of only 0.5 degrees will be sufficient to generate electricity.

This new development leads to a wide spectrum of applications. Besides recharging batteries, electrical appliances can operate off the body heat of the users. For example, a soldier who needs to carry several vitally important electrical items would not be restricted by an invisible leash tying him to the nearest recharging point. A hospital would be able to move patients with greater ease by running a patient's numerous health monitors off their own body, not to mention cutting the hospital's electrical cost.

Someone dared to dream and thus new innovation is coming. My fellow Gardenians, let us dare to dream hard and work hard simultaneously. Who can limit us of what may come forth from our determination?

Source: http://www.fraunhofer.de/fhg/EN/pre ss/pi/2007/08/Researchnews82007T
opic1.jsp (Accessed on 21st August 2007) http://www.gizmag.com/go/7731 (Accessed on 21st August 2007) “Soon, charge mobiles with body heat”, Times Trends, The Times of India, Bangalore. 20th August 2007