Model and Characterization of a Press-Button-Type Piezoelectric Energy Harvester

In this paper, a press-button-type piezoelectric energy harvester (PEH) is presented. The proposed device is composed of a piezoelectric bender, four magnets, a button, and a reverted spring. The proposed structure is triggered by an impact driven by magnetic force, so this novel trigger mechanism enhances its optimal power output. Based on the piezoelectricity, beam theory, and the vibration theory, a complete numerical model was developed to simulate and predict the output voltage. A prototype was fabricated for verification, and the characterization of the energy harvester was measured. The harvested power and energy by a single impact was recorded as 20 mW and 190 μJ, respectively, at an optimum resistive load of 30 kΩ. The measured data agreed with the results of numerical model. Finally, the piezoelectric energy charger extractor (PECE) was used to store the harvested energy. The energy stored in a capacitor of 1 μF was 42.1 μJ.