Abstract
The propagation of longitudinally polarized acoustic modes along thin piezoelectric plates (BN, ZnO, InN, AlN and GaN) is theoretically studied, aiming at the design of high frequency electroacoustic devices suitable for work in liquid environments. The investigation of the acoustic field profile across the plate revealed the presence of longitudinally polarized Lamb modes, travelling at velocities close to that of the longitudinal bulk acoustic wave propagating in the same direction. Such waves are suitable for the implementation of high-frequency, low-loss electroacoustic devices operating in liquid environments. The time-averaged power flow density, the phase velocity and the electroacoustic coupling coefficient K2 dispersion curves were studied, for the first (S0) and four higher order (S1, S2, S3, S4) symmetrical modes for different electrical boundary conditions. Two electroacoustic coupling configurations were investigated, based on interdigitated transducers, with or without a metal floating electrode at the opposite plate surface. Enhanced performances, such as a K2 as high as 8.5% and a phase velocity as high as 16,700 m/s, were demostrated for the ZnO- and BN-based waveguides, as an example. The relative velocity changes, and the inertial and viscous sensitivities of the first symmetric and anti-symmetric mode, S0 and A0, propagating along thin plates bordered by a viscous liquid were derived using the perturbation approach. The present study highlights the feasibility of the piezoelectric waveguides to the development of high-frequency, integrated-circuits compatible electroacoustic devices suitable for working in liquid environment.
Highlights
The medical, food, and manufacturing industry, to name just a few, are increasingly demanding sensors for the investigation of liquids’ properties, such as viscosity, liquid identification and bio-sensing
In the present paper the theoretical performances of BN, AlN, GaN, InN and ZnO-based electroacoustic devices have been explored for liquid sensing applications where the Anisimkin Jr. modes (AMs)-based device acts as a readout technique
This paper proposes the theoretical analysis of Lamb waves propagating along thin piezoelectric membranes with two types of electrode arrangement, aimed at the development of a small, completely integrated sensor for monitoring the properties of liquids
Summary
The medical, food, and manufacturing industry, to name just a few, are increasingly demanding sensors for the investigation of liquids’ properties, such as viscosity, liquid identification and bio-sensing. Group-III nitrides, such as AlN, GaN, InN, and BN, and II-VI materials, such as ZnO, are the current focus of the present investigation since they possess a number of attractive properties that allow to fabricate novel device structures with great potential in high-power electronics and SAW devices applications These piezoelectric thin films materials can be grown on silicon substrates by a variety of thin film deposition processes including sputtering, chemical vapor deposition or molecular beam epitaxy, with or without the presence of a seed layer to reduce the lattice mismatch between the film and the substrate. In the present paper the theoretical performances of BN, AlN, GaN, InN and ZnO-based electroacoustic devices have been explored for liquid sensing applications where the AMs-based device acts as a readout technique Such sensors offer the advantage to work at high frequency, to be fully compatible with the IC technology and suitable for prospective applications in remote acoustic sensing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
