This mini voltage converter could make a battery-free MP3 player a reality.

Engineers at the Fraunhofer Institute for Integrated Circuits have developed the world’s first voltage converter that can work with a minimum input voltage of only 20 mV. This enables driving energy-saving electric devices with a minimal amount of ambient energy. One possible energy source is the transformation of body heat via a thermo-generator to usable current. This makes an MP3 player feasible that requires neither a wall outlet nor batteries.

The 1.5 x 1.5 mm voltage converter can be used in combination with a thermo-generator "wherever there is even a small temperature difference," according to Peter Spies of the area of Performance Optimized Systems. A thermo-generator delivers a very low voltage, which the new voltage converter then transforms into usable voltages. Even with a temperature difference of only 2 °C, as between human skin and room temperature, the voltage converter combined with a thermo-generator of only 4 m² can deliver 4 mw of power. This suffices to directly operate autonomous sensor networks in domains such as environmental monitoring and security. Likewise other weak energy sources such as solar cells under poor lighting would be adequate for the new voltage converter.

For truly power-hungry devices such as MP3 players and PDAs, direct energy supply via low temperature differences is not yet possible. However, it might be possible to use harvested energy over a longer time range to load a rechargeable battery. With ever more efficient solutions for thermal energy recovery, one day it might be possible to implement a completely battery-free MP3 player.

Source: Pressetext.at