Acoustic Microscopy: Fundamentals and Applications , Roman Gr. Maev , Wiley-VCH, Weinheim, Germany, 2008. $179.00 (273 pp.). ISBN 978-3-527-40744-6
Acoustic waves are a useful choice for microscopy for two reasons: They can penetrate optically opaque media—hence the use of ultrasound imaging in medicine; and they reveal an object’s elastic and viscoelastic properties, the primary benefit of highresolution acoustic microscopy. Resolution from the use of acoustic waves in the gigahertz frequency range is comparable to that of a good optical microscope; useful resolution can even be obtained at high megahertz frequencies.
In his book, Acoustic Microscopy: Fundamentals and Applications, Roman Maev has written an authoritative account of the fundamentals and applications of the technique. Maev is well qualified for the task. The research in high-resolution ultrasonics in his laboratory at the Institute of Chemical Physics in Moscow led to the creation of the acoustic microscopy center in the Russian Academy of Sciences. Several brilliant researchers have graduated from his labs; many of them now hold academic positions throughout the world. In 1997, Maev moved to the University of Windsor in Canada where he has continued to apply acoustic microscopy to the characterization of biological tissue and other materials.
Maev’s text is a systematic coverage of the subject. The first three chapters introduce the principles of operation and image formation. Maev provides a rigorous theoretical analysis, a focus common among scientists trained in Russia. Subsequent chapters present methods to deduce the local elastic properties of a sample and to obtain higher resolution by exploiting non-linearity for harmonic generation. Also discussed are the effects of radiation pressure and how it can deform biological tissue and cells.
The final three chapters of the book describe applications of acoustic microscopy, including some areas in which Maev has worked. Those chapters provide images and microelastic measurements of collagen, photographic film, high-temperature superconductors, and multilayer fiberglass–graphite composites. As explained in chapter 7, acoustic microscopy has a particular benefit when applied to composite materials. Unlike materials of higher elastic stiffness, polymers do not give Rayleigh wave contrast. However, the different phases in polymer blends show contrast that can be correlated with the differences in their mechanical properties. The last chapter explains how acoustic microscopy can probe the microstructure and viscoelastic properties of biological tissue. Melanoma cells, kidney tissue, human skin and eye sclera, mouse liver, rat myocardium, bone in the vicinity of an implant, and carious dental tissue have all yielded the secrets of their mechanical structure to acoustic microscopy.
Exciting and significant new developments in acoustic microscopy have emerged in the past decade or so. One is the growing use of focused imaging with ultrasonic waves at frequencies for which the radiation penetrates significantly into opaque materials. Rather than pushing the limits of microscopic resolution, that technique enables nondestructive inspection of small components such as those in electronic equipment.
Another new development combines ultrasonic excitation with atomic force microscopy to probe a material’s elastic properties at nanoscale resolution. The approach can be applied to such problems as the characterization of cracking and debonding in nanocomposite packaging materials—glass layers on polymer substrates—that inhibit the penetration of oxygen and water. Maev’s book mentions that development, albeit only in a foreword written by acoustic-microscopy pioneer Calvin Quate. I consider it significant enough that in the upcoming second edition of my own book, Acoustic Microscopy (Oxford University Press, first published in 1992), I have included an entire chapter written with Oleg Kolosov describing acoustically excited probe microscopy and its applications.
Maev’s Acoustic Microscopy will be a handy reference for materials scientists, electrical engineers, life scientists, and graduate students in any discipline that calls for microscopic characterization of elastic structure. The technique continues to offer the capability to image and measure elastic properties on the microscopic scale, and I have every hope that Maev’s text will help to stimulate further advances in its use.
