Measurements of Piezoelectric Coefficient d33 of Lead Zirconate Titanate Thin Films Using a Mini Force Hammer

Abstract

Lead zirconate titanate (PbZrxTi1-xO3, or PZT) is a piezoelectric material widely used as sensors and actuators. For microactuators, PZT often appears in the form of thin films to maintain proper aspect ratios. One major challenge encountered is accurate measurement of piezoelectric coefficients of PZT thin films. In this paper, we present a simple, low-cost, and effective method to measure piezoelectric coefficient d33 of PZT thin films through use of basic principles in mechanics of vibration. A small impact hammer with a tiny tip acts perpendicularly to the PZT thin-film surface to generate an impulsive force. In the meantime, a load cell at the hammer tip measures the impulsive force and a charge amplifier measures the responding charge of the PZT thin film. Then the piezoelectric coefficient d33 is obtained from the measured force and charge based on piezoelectricity and a finite element modeling. We also conduct a thorough parametric study to understand the sensitivity of this method on various parameters, such as substrate material, boundary conditions, specimen size, specimen thickness, thickness ratio, and PZT thin-film material. Two rounds of experiments are conducted to demonstrate the feasibility and accuracy of this new method. The first experiment is to measure d33 of a PZT disk resonator whose d33 is known. Experimental results show that d33 measured via this method is as accurate as that from the manufacturer's specifications within its tolerance. The second experiment is to measure d33 of PZT thin films deposited on silicon substrates. With the measured d33, we predict the displacement of PZT thin-film membrane microactuators. In the meantime, the actuator displacement is measured via a laser Doppler vibrometer. The predicted and measured displacements agree very well validating the accuracy of this new method.

Effective piezoelectric coefficient measurement of BaTiO3 thin films using the X-ray diffraction technique under electric field available in a standard laboratory

“…This coefficient can be determined by different methods, either direct or converse piezoelectric effect. Among the first category, one can measure the charge induced when a stress is applied (such measures can be found inter alia in the Berlincourt method [8]), the impulse method with the mini force hammer [9] or the sample flexure technique [10]. The d ij coefficient can also be determined by converse piezoelectric effect, where the deformation is measured by applying external electric field.…”

Portable lysis apparatus for rapid single-step DNA extraction of Bacillus subtilis

“…; Uchino ; Guo et al . ). In this case by virtue of the arrangement, the vibration of the annular piezoelectric disc would force the perforated steel diaphragm into an out‐of‐plane vibration.…”

Identification of the electromechanical material properties of a multilayer ceramic capacitor

“…These coefficients are commonly determined using two approaches . The Berlincourt method, also called the quasi‐static method, applies a static load or a dynamically varying load to a bulk ceramic specimen and measures the corresponding charge or voltage change . Although this method is fast and convenient, both piezoelectric and electrostrictive coefficients cannot be derived simultaneously because electrostriction has no reverse effect .…”

“…8,9 The Berlincourt method, also called the quasi-static method, applies a static load or a dynamically varying load to a bulk ceramic specimen and measures the corresponding charge or voltage change. [10][11][12] Although this method is fast and convenient, both piezoelectric and electrostrictive coefficients cannot be derived simultaneously because electrostriction has no reverse effect. 13 The alternative approach determines the coefficients from measurements of strain or vibration caused by an electric field applied to the specimen [14][15][16] ; we used this latter method.…”