Comparison of different beam shapes for piezoelectric vibration energy harvesting

Abstract

International audienceThis paper reports the comparison of different beam shapes of piezoelectric vibration energy harvesters in regards to their stress level and power harvestable. We proved that trapezoidal and circular shapes allow to reduce the stress level in the material for a low decrease of the power harvested at a given resonance frequency, which increases the reliability of the device. The reliability of the piezoelectric harvesters and in particular their tolerance to high accelerations are an important problematic. We are also developing a process to fabricate home made MEMS piezoelectric harvesters, and the first devices have been fabricated