Energy harvesting from low-frequency sinusoidal vibrations using diaphragm type piezoelectric element

Piezoelectric has great potential in energy harvesting. In the present work, investigations have been made on harvesting mechanical vibration energy by a diaphragm type piezoelectric element. The piezoelectric element has been placed at the center of a fix-free-fix-free rectangular plate. Excitation to the plate in the range of 10 Hz-150 Hz frequencies and 10 mVpp to 150 mVpp amplitude has been applied by a model exciter. The output from piezoelectric element has been measured in terms of current and voltage. The experimental results have revealed that the power output of piezoelectric increases with an increase in input amplitude. However, at constant input amplitude (150 mVpp) in the frequency range 10 Hz to 150 Hz, the power output has attained its maximum value (902 μW) at frequency 60 Hz. Further, the energy harvesting capabilities have also been investigated near the natural frequency band of the structure. The results have showed that in the natural frequency band, even a low amplitude excitation can also increase power output from the piezoelectric element. It has been concluded that using a piezoelectric element, vibration energy can be converted into electrical energy to operate small gadgets.