Optimization for cantilever piezoelectric energy harvester with a cavity

The structure optimization of piezoelectric energy harvester aims at frequency reduction, broadening bandwidth and increasing output mainly. This paper employs a cantilever with cavity modelled by the finite element software COMSOL Multiphysics and the effect of the cavity on transducer is studied. The first order characteristic frequency is obtained by modal analysis module and the frequency response curve is solved by frequency domain analysis module. Comparison results show that the introducing of cavity improves output voltage of energy harvester and reducing device nature frequency. Moreover, effect of the cavity size parameters such as the thickness, length and position on frequency, output and conversion rate of the harvester is studied, after that the energy harvester structure is optimized.