The Radial Electric Field Excited Circular Disk Piezoceramic Acoustic Resonator and Its Properties

Abstract

A new type of piezoceramic acoustic resonator in the form of a circular disk with a radial exciting electric field is presented. The advantage of this type of resonator is the localization of the electrodes at one end of the disk, which leaves the second end free for the contact of the piezoelectric material with the surrounding medium. This makes it possible to use such a resonator as a sensor base for analyzing the properties of this medium. The problem of exciting such a resonator by an electric field of a given frequency is solved using a two-dimensional finite element method. The method for solving the inverse problem for determining the characteristics of a piezomaterial from the broadband frequency dependence of the electrical impedance of a single resonator is proposed. The acoustic and electric field inside the resonator is calculated, and it is shown that this location of electrodes makes it possible to excite radial, flexural, and thickness extensional modes of disk oscillations. The dependences of the frequencies of parallel and series resonances, the quality factor, and the electromechanical coupling coefficient on the size of the electrodes and the gap between them are calculated.

The Study of the Acoustic Characteristics of Chitosan Acetate Film Using a Radial Electric Field Excited Resonator

“…The commercial name of this ceramic is VA-650, and its chemical composition is Pb 0.75 Ba 0.25 (Zr 0.53 Ti 0.47 )O 3 . As was shown in [ 22 ], this ceramic has the required symmetry, and its resonators are characterized by a high quality factor (Q > 2400 for the F 0 mode) and a high electromechanical coupling coefficient (K 2 = 6.6% for the F 6 mode). So, this material is the most suitable for our purpose among all Russian-made ceramics available to us.…”

“…We solve the problem of forced oscillations of a circular piezoceramic disk excited by a pair of concentric electrodes located on one side of the disk. Such a problem was considered in [ 22 ], so here we will only briefly recall its formulation. A disk with diameter d and thickness h , made of piezoceramics belonging to the crystallographic class of 6 mm, is considered.…”

“…The corresponding boundary conditions are also considered [ 22 ]. A mechanical boundary condition is specified on the disk axis in the following form: …”

“…In our previous works [ 22 , 25 ], the resonators were made from blanks purchased from Aurora-ELMA LLC, Volgograd, Russia. The commercial name of this ceramic is VA-650, and its chemical composition is Pb 0.75 Ba 0.25 (Zr 0.53 Ti 0.47 )O 3 .…”

A Virtual Instrument for Measuring the Piezoelectric Coefficients of a Thin Disc in Radial Resonant Mode

“…Piezoceramics present the so-called piezoelectric effect, which consists of the polarisation of the material following a certain polar axis when the piezoceramic is subjected to mechanical traction or compression [1,2]. The polarisation of the material causes an accumulation of a charge in one direction or another of its polar axis, manifesting as a potential difference in the faces of the crystals [3][4][5][6][7][8]. This phenomenon is called the direct piezoelectric effect.…”