VACUUM PACKAGED MEMS PIEZOELECTRIC VIBRATION ENERGY HARVESTERS

This paper describes the characterization of thin film MEMS vibration energy harvesters based on aluminum nitride as piezoelectric material. A record output power of 85 μW has been measured. The parasitic damping contributions present in vacuum packaged and unpackaged energy harvesters are investigated. It is found that vacuum packaging of the harvester is essential for maximizing the output power. Therefore, a wafer-scale vacuum package process has been developed.