Date of Award

2010

Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Electrical and Computer Engineering

Advisor

John F. Vetelino

Second Committee Member

David Frankel

Third Committee Member

Mauricio Pereira da Cunha

Abstract

Acoustic wave sensor platforms typically consist of piezoelectric materials in which bulk or surface acoustic waves are excited by metallic transducers deposited on the sensing surface of the platform. This type of transduction has limitations. In particular the transducer may limit the type of sensing film that can be used or analyte that can be measured and limit the frequency of operation of the sensor. In this work a novel method of exciting high frequency bulk acoustic waves in piezoelectric sensor platforms has been explored. This technique consists of applying time varying electromagnetic fields to the sensor platform using an antenna in order to excite high order harmonic acoustic waves. This configuration is known as a Monolithic Spiral Coil Acoustic Transduction (MSCAT) device. This technique offers benefits such as a bare sensing surface that allows for the detection of both mechanical and electrical property changes in the film or analyte and is capable of operating at high frequencies by exciting high order harmonics (> 99th harmonic) in the substrate. The antenna configurations have been experimentally and theoretically examined and an understanding of how these electric fields excite the acoustic waves in the substrate has been developed. Finally, the MSCAT sensor platform was used to detect real world chemical and biological analytes and found in many cases to be superior to other bulk acoustic wave sensor platforms.

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