Simulation and Experiment of Trapezoidal Beam‐Based Piezoelectric Energy Harvesters

Abstract

Piezoelectric energy harvesters (PEHs) are thought to be one of the best ways to power wireless sensors. However, how to improve the electrical properties of PEHs is still a key matter. Herein, a trapezoidal beam (TB) is adopted to improve the electrical outputs of PEHs, where the elastic substrate and thinned piezoelectric ceramic element are combined to obtain a piezoelectric beam with 100 μm total thickness. The simulation results indicate that the TB‐based piezoelectric energy harvester (TB‐PEH) possesses a better electrical output performance than the traditional rectangular beam‐based piezoelectric energy harvester (RB‐PEH). The presented TB‐PEH can generate a 5.4 V voltage output, and an average power of 0.2 mW with the 55 kΩ optimal resistance. The 100, 220, and 470 μF capacitors are used to demonstrate charging from the TB‐PEH, and these capacitors are saturated at 5.1, 5.0, and 4.9 V during 40, 85, and 175 s charging time, respectively. The energy harvester can generate enough power to directly light up four light emitting diodes in real time, indicating its potential to be used as microenergy source for wireless sensor networks in mechanical vibration circumstance under harmonic vibration excitation. The proposed TB‐PEH is conclusively proved potential for charging low‐power electronic devices.