Modeling of a Piezoelectric Energy Harvester Mounted on a Quick-Return Mechanism
Piezoelectric materials are being used to harvest mechanical energy from ambient vibration and convert it to electrical energy. They are mainly used to power miniature wireless sensors such as accelerometers, tachometers and proximity probes, which are commonly used for machine monitoring applications. However, exciting a piezoelectric cantilever with its resonance frequency for maximum power output remains to be a challenge. This is because the natural frequency of piezoelectric cantilevers is much higher than the common ambient vibrations. This study answers the research question: “Does a quick-return mechanism enhance the power output of a piezoelectric energy harvester?” For this purpose, analytical methods were employed to model a piezoelectric energy harvester mounted on a quick-return mechanism. The proposed mechanism was able to generate approximately 13.5mW of power, which is 35%–75% greater than the existing designs. A study on the working frequency range of the harvester for maximum power output was employed by varying the dimensional parameters of the quick-return mechanism. It was determined that by varying the dimensions of the quick return it is possible to harvest maximum power at a range of excitation frequencies. It was demonstrated that the system can effectively produce the maximum power when excited at frequencies ranging from 2rad/s to 46rad/s.