Acoustic Wave Sensors

Written by an interdisciplinary group of experts from both industry and academia, Acoustic Wave Sensors provides an in-depth look at the current state of acoustic wave devices and the scope of their use in chemical, biochemical, and physical measurements, as well as in engineering applications. Because of the inherent interdisciplinary applications of these devices, this book will be useful for the chemist and biochemist interested in the use and development ofthese sensors for specific applications; the electrical engineer involved in the design and improvement of these devices; the chemical engineer and the biotechnologist interested in using these devices for process monitoring and control; and the sensor community at large. Provides in-depth comparison and analyses of different types of acoustic wave devices Discusses operating principles and design considerations Includes table of relevant material constants for quick reference Presents an extensive review of current uses of these devices for chemical, biochemical, and physical measurements, and engineering applications

In this book, application-related studies for acoustic biomedical sensors are covered in depth. The book features an array of different biomedical signals, including acoustic biomedical signals as well as the thermal biomedical signals, magnetic biomedical signals, and optical biomedical signals to support healthcare. It employs signal processing approaches, such as filtering, Fourier transform, spectral estimation, and wavelet transform. The book presents applications of acoustic biomedical sensors and bio-signal processing for prediction, detection, and monitoring of some diseases from the phonocardiogram (PCG) signal analysis. Several challenges and future perspectives related to the acoustic sensors applications are highlighted. This book supports the engineers, researchers, designers, and physicians in several interdisciplinary domains that support healthcare.

This book concerns the design, operation and application of devices capable of generating acoustic waves in the ultrasonic frequency range. It emphasizes the study of chemical and/or biochemical systems imposed on the surface of such devices, whether operated in the gas- or liquid-phase, i.e. on acoustic wave chemical and biological sensors. It focuses on devices that employ acoustic waves launched and received on the same surface. It touches upon such diverse areas as acoustic wave physics, applied mathematics, chemistry, electronics, fluid mechanics, materials science and polymer science.

Acoustics is a mature field which enjoys a never ending youth. New developments are induced by either the search for a better understanding, or by technological innovations. Micro-fabrication techniques introduced a whole new class of microdevices, which exploit acoustic waves for various tasks, and in particular for information processing and for sensing purposes. Performance improvements are achievable by better modelling tools, able to deal with more complex configurations, and by more refined techniques of fabrication and of integration in technological systems, like wireless communications. Several chapters of this book deal with modelling and fabrication techniques for microdevices, including unconventional phenomena and configurations. But this is far from exhausting the research lines in acoustics. Theoretical analyses and modelling techniques are presented, for phenomena ranging from the detection of cracks to the acoustics of the oceans. Measurement methods are also discussed, which probe by acoustic waves the properties of widely different systems.

Surface acoustic wave (SAW) devices are widely used in mobile communications, a rapidly evolving market. This book gives an overview on the latest SAW technologies with an emphasis on the design and simulation of devices, such as resonator-based devices employing the SH-type leaky SAW.

There were two reasons that induced me to plan and to organize this book, the first was the lack of a text entirely devoted to the subject of gas sensors, notwithstanding some books devoted to the various kind of chemical sensors have recently been published. The second reason was the need of introducing the basic topics of gas detection mechanisms to a growing number of researchers active in research and development laboratories of industries and uni versities. The field of chemical sensors is indeed in fast and consistent growth, as it is proved by the increased number of participants to the congresses that were recently held on this subject, namely the Third Meeting on Chemical Sensors (September 24 - 26, 1990, Cleveland), Transducers' 91 (June 24 - 27, 1991, S. Francisco) and EUROSENSORS V (September 30 - October 3, 1991, Rome). Therefore, this book is mainly intended as a reference text for researchers with a MS degree in physics, chemistry and electrical engineering; it reports the last progresses in the R. & D. and in the technology of gas sensors. I choose to deal specifically with the topic of gas sensors because these devices show a very large number of applications in the domestic and industrial field and they are characterized by a great effort of research and development.

Written at an intermediate level in a way that is easy to understand, Fundamentals and Applications of Ultrasonic Waves, Second Edition provides an up-to-date exposition of ultrasonics and some of its main applications. Designed specifically for newcomers to the field, this fully updated second edition emphasizes underlying physical concepts over mathematics. The first half covers the fundamentals of ultrasonic waves for isotropic media. Starting with bulk liquid and solid media, discussion extends to surface and plate effects, at which point the author introduces new modes such as Rayleigh and Lamb waves. This focus on only isotropic media simplifies the usually complex mathematics involved, enabling a clearer understanding of the underlying physics to avoid the complicated tensorial description characteristic of crystalline media. The second part of the book addresses a broad spectrum of industrial and research applications, including quartz crystal resonators, surface acoustic wave devices, MEMS and microacoustics, and acoustic sensors. It also provides a broad discussion on the use of ultrasonics for non-destructive evaluation. The author concentrates on the developing area of microacoustics, including exciting new work on the use of probe microscopy techniques in nanotechnology. Focusing on the physics of acoustic waves, as well as their propagation, technology, and applications, this book addresses viscoelasticity, as well as new concepts in acoustic microscopy. It updates coverage of ultrasonics in nature and developments in sonoluminescence, and it also compares new technologies, including use of atomic force acoustic microscopy and lasers. Highlighting both direct and indirect applications for readers working in neighboring disciplines, the author presents particularly important sections on the use of microacoustics and acoustic nanoprobes in next-generation devices and instruments.

SAW devices are widely used in multitude of device concepts mainly in MEMS and communication electronics. As such, SAW based micro sensors, actuators and communication electronic devices are well known applications of SAW technology. For example, SAW based passive micro sensors are capable of measuring physical properties such as temperature, pressure, variation in chemical properties, and SAW based communication devices perform a range of signal processing functions, such as delay lines, filters, resonators, pulse compressors, and convolvers. In recent decades, SAW based low-powered actuators and microfluidic devices have significantly added a new dimension to SAW technology. This book consists of 20 exciting chapters composed by researchers and engineers active in the field of SAW technology, biomedical and other related engineering disciplines. The topics range from basic SAW theory, materials and phenomena to advanced applications such as sensors actuators, and communication systems. As such, in addition to theoretical analysis and numerical modelling such as Finite Element Modelling (FEM) and Finite Difference Methods (FDM) of SAW devices, SAW based actuators and micro motors, and SAW based micro sensors are some of the exciting applications presented in this book. This collection of up-to-date information and research outcomes on SAW technology will be of great interest, not only to all those working in SAW based technology, but also to many more who stand to benefit from an insight into the rich opportunities that this technology has to offer, especially to develop advanced, low-powered biomedical implants and passive communication devices.