Criterion for material selection in design of bulk piezoelectric energy harvesters

Vibration energy harvesting has gained tremendous attention in the past decade and continues to grow rapidly. There are various transduction mechanisms for converting the vibration energy into electrical energy, out of which the piezoelectric mechanism has been shown to provide advantages at the micro-to-meso scale. In the past few years, several studies have tried to address the question of which piezoelectric composition is better for energy harvesting; however, discussion on this subject continues. The intent of this letter is to provide an answer for this question through a simple criterion which can be used in routine material evaluation.