Fundamentals and Applications of Ultrasonic Waves , J. David N. Cheeke , CRC Press, Boca Raton, Fla., 2002. $99.95 (462 pp.). ISBN 0-8493-0130-0
Imagine an introduction to ultrasonics that brings a student from basic acoustics to the forefront of current ultrasonics research. Such a textbook could become indispensable, and David Cheeke’s Fundamentals and Applications of Ultrasonic Waves succeeds in its avowed purpose of becoming such a text. Since Cheeke has made significant contributions in the applied ultrasonics fields he discusses in the latter part of his book, he can present the topics authoritatively.
Throughout the book, Cheeke balances elementary introduction and advanced application; his discussion of advanced application extends to current research in theoretical and experimental ultrasonics. Nonetheless, wherever possible, Cheeke uses qualitative models to elucidate complex concepts he has derived mathematically but whose full physical implications may be opaque to the neophyte. In introducing ultrasonic measurement techniques, he enumerates the steps and methods—and also the pitfalls that await the unsuspecting novice.
After a beautiful introduction to the prevalence of ultrasonics in nature and its emergence in our technological world, Cheeke devotes six chapters to fundamental acoustics. Much of that material could be found in a few undergraduate textbooks, the most familiar being Fundamentals of Acoustics by Lawrence Kinsler, Austin Frey, Alan Coppens, and James Sanders (Wiley, 2000). However, even in his first six chapters, Cheeke goes beyond the usual scope of undergraduate textbooks when discussing certain topics to be used in later chapters.
After chapter 6, Cheeke begins to discuss topics more specific to ultrasonic propagation, gradually introducing the reader to Rayleigh waves, Lamb waves, and acoustic waveguides. The propagating waves discussed are the main ones used in the succeeding application chapters. In a transition chapter, he discusses group velocities, velocity surfaces, and slowness surfaces, important concepts for analyzing wave propagation and in designing ultrasonic-measurement systems. An ultrasonic device requires some sort of mechanical transduction to produce sound energy. To introduce transduction, Cheeke first discusses piezoelectricity and then presents the piezoelectric constitutive relations and the piezoelectric coupling factor. Once he acquaints the reader well with these concepts, he qualitatively extends them to other forms of transduction involving electricity and magnetism, optics, and heat.
The final six chapters successfully present modern applications of ultrasonics. Cheeke starts with the most elementary applications, namely piezoelectric transducers, delay lines, and analog signal processing. He ends with one of the most intriguing problems of modern ultrasonics—sonoluminescence, the emission of light by collapsing bubbles in a liquid undergoing cavitation. At its minimum radius, such a bubble is predicted to have a central temperature between 20 000 K and 30 000 K. Poetically, the author describes the phenomenon as “‘a star in a bottle’ with a hot optically opaque center and a cooler optically thin outer region.” For a discussion of sonoluminescence, see Detlef Lohse’s article in Physics Today (February 2003, page 36).
A principal focus of the book is the physics and design of ultrasonic sensors. Typically of most texts, the first chapters cover reflection, refraction, and transmission through various media. But then Cheeke launches into detailed discussions of waves in different environments: on surfaces, in the bulk, in media sandwiched between two structures, trapped near surfaces, leaking away from surfaces, in films, in thin plates, and in cylinders. Those environments support such phenomena as surface acoustic waves, longitudinal and transverse bulk waves, trapped acoustic waves, cutoff modes, dispersion modes, and symmetric and antisymmetric modes. For the general case, he derives in detail the pertinent wave equations and dispersion relations. For special cases, he outlines advanced techniques for solving the equations and then presents the principal results. For the most specialized uses, he simply presents results and gives qualitative phenomenological discussions that make them plausible.
Because it relies on the knowledge acquired in the previous chapters, chapter 13 on sensors must have been the most difficult to organize, but Cheeke meets the challenge and continues to balance fundamentals with applications. In that chapter, he first derives general ultrasonic-wave sensitivity relations for such factors as mass loading, fluid viscosity, and temperature. He then uses the equations for reflections at intermediate boundaries to deduce the effectiveness of certain ultrasonic-wave modes as ultrasonic sensors. Through simple models based on sensitivity results derived from reflection and refraction relations, he conveys the physical processes that are important in sensor design. Finally, he discusses ultrasonic sensors used as mass detectors; as level, temperature, density, viscosity, and flow sensors; and in gas chromatography and in biosensing devices.
Each of the first 10 chapters ends with an excellent summary and provocative and instructive questions. Therefore, one is left at a loss when these summaries are absent from the last seven chapters. Perhaps Cheeke had some self-referential intent when he stated in the acknowledgments that authors are sometimes compelled by publishers’ deadlines to abandon the full completion of their books. Even so, I think the outlines of the application chapters presented in the table of contents are enough to navigate through the engrossing topics within those chapters.
