Thesis
Acoustic transducers based on curved membranes
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/103516
Abstract
Piezoelectric materials are utilized widely in a variety of MEMS applications. In order to achieve the maximum performance of piezoelectric thin films, the resonant frequency, residual stress and elastic modulus have been investigated. However, an important parameter is the electromechanical coupling coefficient that converts mechanical to electrical energy. This study focuses on the effect of piezoelectric thin films with different thickness on the performance of composite thin film membranes. Using both static and dynamic bulge testing, the residual stress and elastic modulus can be determined after curve fitting, also, the electromechanical coupling coefficient can be calculated. In addition, the resonant frequency of the membrane with different PZT thickness was studied. Electromechanical coupling was tested at a frequency of 5 kHz which is not the resonant frequency of the membrane. The result shows that the resonant frequencies are 8.83, 21.95 and 17.92 kHz for 1.2, 1.6 and 3.8-thick PZT film, respectively. Moreover, the residual stress decreased as piezoelectric film thickness increased. The residual stresses are 30.72 and 10.51 MPa for 1.2 and 3.8 mm, respectively. Also, the composite elastic modulus decreased from 144.8 to 70.99 GPa with piezoelectric film thickness increased from 1.2 to 3.8 mm. The electromechanical coupling coefficient increased as the PZT thickness increased and as the bias pressure increases.
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Details
- Title
- Acoustic transducers based on curved membranes
- Creators
- Chinhui Chang
- Contributors
- David F. Bahr (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525274301842
- Language
- English
- Resource Type
- Thesis