Lead–Zirconate–Titanate Acoustic Energy Harvesters with Dual Top Electrodes

Abstract

In this paper, we present the power generation performances of a lead–zirconate–titanate (PZT) microelectromechanical system (MEMS) acoustic energy harvester having dual top electrodes to utilize the different polarizations of charges on the surface of a vibrating PZT diaphragm at first resonance. The PZT acoustic energy harvester had a diaphragm with a diameter of 2 mm consisting of Al (0.1 µm)/PZT (1 µm)/Pt (0.1 µm)/Ti (0.1 µm)/SiO2 (1.5 µm), and the diaphragm vibrations were excited by sound pressure. The top Al electrodes independently cover the peripheral surface and the central surface of the PZT diaphragm. The peripheral energy harvester generated a power of 5.28×10-11 W, and the central energy harvester generated a power of 4.25×10-11 W at a sound pressure level of 100 dB (0.01 W/m2) at 4.92 kHz. Thus, nearly 80% of the total power of the energy harvesters can be increased by utilizing the polarization at the central part of the diaphragm, which was usually not considered when only the peripheral part of the diaphragm was utilized.

Mechanical Energy Sensing and Harvesting in Micromachined Polymer-Based Piezoelectric Transducers for Fully Implanted Hearing Systems: A Review

“…An acoustic piezoelectric energy harvester of diaphragm configuration with a cavity underneath is fabricated to scavenge power from sound input [ 49 ]. The thin film PZT MEMS acoustic energy harvester possesses dual top electrodes that manipulate different polarisation charges on the surface of the vibrating PZT diaphragm, at the first mode.…”

“… ( a ) Top view and ( b ) cross sectional view of the PZT diaphragm energy harvester. ( c ) Possible charge distribution at first mode and ( d ) the conceptual schematic of peripheral and central energy harvesting [ 49 ]. Copyright (2011) The Japan Society of Applied Physics.…”

Preparation of Pb(Mg1/3Nb2/3)TiO3–PbTiO3 thick films with highly preferred orientation via screen printing

“…Piezoelectric thin and thick films are adapted for use in electrical devices, such as energy harvesters, actuators, and sensors. [1][2][3][4][5] However, the sizes of the materials used in film preparation widely differ between thin films and thick films. Piezoelectric thin films are commonly fabricated via sputtering, CVD, and chemical solution deposition.…”

Enhanced Acoustic Energy Harvesting Using Coupled Resonance Structure of Sonic Crystal and Helmholtz Resonator

“…Several systems for harvesting acoustic energy have been proposed. [13][14][15][16][17][18][19][20] For example, Horowitz and coworkers have developed an electromechanical Helmholtz resonator (EMHR) by utilizing the resonant cavity pressure to deform a piezoelectric back plate. 13,14) Under an external acoustic pressure of 160 dB (ref.…”

“…To improve the performance of the harvester, efficient approaches have been developed by using the load matching, dual top electrode and nonlinear optimization mechanisms. 14,15,17) In addition, the sonic crystal resonator (or the sonic crystal with a resonant cavity) has also been used for acoustic energy harvesting. 19,20) Due to the acoustic wave localization effect, 21) the pressure in the cavity of the sonic crystal resonator is amplified 7.2 times.…”