Energy Harvesting

Micro energy harvesting is a relatively new discipline in the field of mobile power supply for small devices and off-grid applications. In particular, thermo-electric and piezoelectric energy conversion processes are applied here. In thermoelectric energy conversion, a temperature gradient is converted into electrical energy. Piezoelectric energy conversion is based on the generation of electrical voltages through pressure or vibrations. Systems designed by the Fraunhofer Energy Alliance can, for example, provide energy for the radio transmission of sensor signals during function monitoring in moving or remote plants.



Competencies of the Fraunhofer Energy Alliance in the Field of Energy Harvesting

Thermoelectric Converters

Energy harvesting is the use of energy from the environment to supply small electronic consumers. In this context, institutes of Fraunhofer-Gesellschaft develop efficient thermoelectric energy converters for different temperature ranges, technologies for the integration of thermoelectrics in higher power modules, AC-DC converters for thermo- or electrodynamic generators as well as electrically functional structural ceramics that act as heat conductors.




The aim of the INTEGRAL project is to upscale the GEN2 TE material technology using existing pilot lines and growing SMEs, in order to address mass markets TE needs (automotive, heavy duty trucks, autonomous sensors and industry waste heat recovery).



Thermoelectrics: old effect with big potential for the future

Piezoelectric Converters

In the field of energy harvesting, both thermoelectric and piezoelectric energy converters are used to supply small electrical consumers with energy from the environment. In the process, mechanical energy is converted into electrical energy, for example by means of AC-DC converters for piezo generators. Fraunhofer research has implemented corresponding technologies in numerous projects, for example in a digital writing and learning pen with energy-autonomous sensors or motion-sensitive clothing used in the health sector.




Self-sufficient sensors are to be implemented in a digital pen for recording handwritten records. The data is then transmitted to a computer via a wireless connection.


MEMS Energy-Harvesting

The Fraunhofer lead project "Toward Zero Power Electronics" is working on the development of energy-efficient and modular hardware for IoT applications.


Piezoelectric Thin Film Transducers

PZT (abbreviation for Pb(Zr,Ti)O3 ) thin films on metallic substrates can be widely used as piezoelectric sensors and actuator elements (e.g. micromotors, electric transformers and acoustic transducers).