Dimensionless optimization of piezoelectric vibration energy harvesters with different interface circuits

Conversion of mechanical vibration energy into electric energy could provide reliable and efficient energy utilization. Both the harvested resonant power and the energy efficiency have been studied based on a single degree of freedom weak electromechanical coupling piezoelectric vibration energy harvester and normalized in a dimensionless form. Performance optimizations have been conducted for the energy harvester connected with different interface circuits in terms of normalized harvested resonant power and resonant energy harvesting efficiency to identify both qualitatively and quantitatively the best energy extraction and storage interface circuit. Both the dimensionless harvested resonant power and the resonant energy harvesting efficiency formulae have been normalized to contain only two normalized variables of resistance and force factor regardless of the size and excitation magnitude of the energy harvesters.