The energy harvesting technology uses energy available in the natural environment, like light, motion or heat. To derive electrical energy from thermal gradients, thermoelectric generators convert temperature differences into electrical voltages. The produced voltage depends on the temperature gradient applied. With the voltage converter IC developed by Fraunhofer IIS already minimum temperature differences of 1 to 2 degrees Celsius can be used; like the temperature gradient between human skin and the environment.

In addition to that, forces like ambient vibration or acceleration can be converted into electrical energy using piezoelectric effects. The Fraunhofer voltage converter IC can scavenge electric power from low-frequency ambient vibrations, as they occur in civil engineering structures and buildings.

The new energy harvesting systems power electronic devices like transceivers, sensors and displays with electric energy. First industrial application areas are sensor networks for machine and facility condition monitoring, tire pressure monitoring sensors, wireless light switches and sensors for building automation. Energy harvesting systems can also be employed in medical engineering, logistics and the consumer industries. Fraunhofer IIS offers individual components as well as turnkey or customized systems for system and device integration.

Fraunhofer showcases its latest energy harvesting technologies and energy generation systems using thermal gradients and ambient vibrations at the Munich fair Electronica from November 9 to 12, 2010.