Table of Contents
ISRN Mechanical Engineering
Volume 2012, Article ID 635268, 8 pages
http://dx.doi.org/10.5402/2012/635268
Research Article

Characterization and Modelling of Circular Piezoelectric Micro Speakers for Audio Acoustic Actuation

Instituto de Microelectrónica de Sevilla-Centro Nacional de Microelectrónica, c/Américo Vespucio s/n., 41092 Sevilla, Spain

Received 23 September 2011; Accepted 30 October 2011

Academic Editors: J. Hu, D. Kalempa, and X. Yang

Copyright © 2012 J. Mendoza-López et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A study of circular piezoelectric micro speakers is presented for applications in the audio frequency range, including values for impedance, admittance, noise figures, transducer gain, and acoustic frequency responses. The micro speakers were modelled based on piezoelectric micro ultrasonic transducer (pMUT) design techniques and principles. In order to reach the audio frequency range, transducer radii were increased to the order of one centimetre, whilst piezoelectric layer thicknesses ranged the order of several μm. The micro actuators presented might be used for a variety of electroacoustic applications including noise control, hearing aids, earphones, sonar, and medical diagnostic ultrasound. This work main contribution is the characterization of the design space and transducer performance as a function of transducer radius, piezoelectric layer thickness, and frequency range, looking towards an optimized fabrication process.