Vibration energy harvesting with piezoelectric ceramics working in d33 mode by using a spring-mass-spring oscillator

This paper proposed a piezoelectric energy harvester based on a spring-mass-spring oscillator, of which the piezoelectrics operate in the d33 mode. Theoretical analysis reveals that the spring-mass-spring oscillator can not only generate a larger vibration than that of the ambient system but also buffer the force of possible accidental impact applied on the piezoelectric stacks. By using lead zirconate titanate (PZT-4) ceramics as model materials, we systematically characterized the performance of the energy harvester. Results show that at the resonance frequency, the harvester can output a satisfactory electric field. In addition, it has excellent fatigue resistance, e.g., under 9 g vibration acceleration for a long time about 12 h, the electric voltage output of the harvester nearly kept constant and only a slight fluctuation was observed.