Ultrasonic transducers are key components in sensors for distance, flow and level measurement as well as in power, biomedical and other applications of ultrasound. Ultrasonic transducers reviews recent research in the design and application of this important technology.Part one provides an overview of materials and design of ultrasonic transducers. Piezoelectricity and basic configurations are explored in depth, along with electromagnetic acoustic transducers, and the use of ceramics, thin film and single crystals in ultrasonic transducers. Part two goes on to investigate modelling and characterisation, with performance modelling, electrical evaluation, laser Doppler vibrometry and optical visualisation all considered in detail. Applications of ultrasonic transducers are the focus of part three, beginning with a review of surface acoustic wave devices and air-borne ultrasound transducers, and going on to consider ultrasonic transducers for use at high temperature and in flaw detection systems, power, biomedical and micro-scale ultrasonics, therapeutic ultrasound devices, piezoelectric and fibre optic hydrophones, and ultrasonic motors are also described.With its distinguished editor and expert team of international contributors,Ultrasonic transducers is an authoritative review of key developments for engineers and materials scientists involved in this area of technology as well as in its applications in sectors as diverse as electronics, wireless communication and medical diagnostics. - Reviews recent research in the design and application of ultrasonic transducers - Provides an overview of the materials and design of ultrasonic transducers, with an in-depth exploration of piezoelectricity and basic configurations - Investigates modelling and characterisation, applications of ultrasonic transducers, and ultrasonic transducers for use at high temperature and in flaw detection systems

This volume contains the Proceedings of the International Workshop on the Design of Power Sonic and Ultrasonic Transducers, which was held in the Maison de l'Entreprise et des Technologies Nouvelles, Marcq en Baroeul, near Lille, France, on May 26 and 27, 1987. The main objective of this Workshop was to discuss all aspects of high power problems in the design of electroacoustic transducers and to stimulate an exchange of knowledge and experience between researchers and industrial ists involved in this multidisciplinary field. The scientific program included 13 invited contributions, and there were 80 participants from England, France, Italy, Spain, Sweden and the United States. The editors wish to thank the authors and attendees for their active par ticipation, and they hope that these Proceedings will allow readers to share in the stimulating atmosphere of the sessions. They also wish to thank eve ryone who undertook simultaneous translation, clerical work, typing of the Proceedings, production of the illustrations, or any other of the numerous tasks connected with this venture. Special mention has to be made of Mrs. E. Litton (ISEN, Lille) for her constant and kind help from the beginning of the project to the very end of the editing, Dr. R. Bossut (ISEN, Lille) for his efficient proofreading, and Dr. H.U. Daniel (Springer-Verlag) for his interest in these Proceedings as well as his kind and efficient support.

Capacitive micromachined ultrasonic transducers (CMUTs), have been widely studied in academia and industry over the last decade. CMUTs provide many benefits over traditional piezoelectric transducers including improvement in performance through wide bandwidth, and ease of electronics integration, with the potential to batch fabricate very large 2D arrays with low-cost and high-yield. Though many aspects of CMUT technology have been studied over the years, packaging the CMUT into a fully practical system has not been thoroughly explored. Two important interfaces of packaging that this thesis explores are device encapsulation (the interface between CMUTs and patients) and full electronic integration of large scale 2D arrays (the interface between CMUTs and electronics). In the first part of the work, I investigate the requirements for the CMUT encapsulation. For medical usage, encapsulation is needed to electrically insulate the device, mechanically protect the device, and maintain transducer performance, especially the access of the ultrasound energy. While hermetic sealing can protect many other MEMS devices, CMUTs require mechanical interaction to a fluid, which makes fulfilling the previous criterion very challenging. The proposed solution is to use a viscoelastic material with the glass-transition-temperature lower than room temperature, such as Polydimethylsiloxane (PDMS), to preserve the CMUT static and dynamic performance. Experimental implementation of the encapsulated imaging CMUT arrays shows the device performance was maintained; 95 % of efficiency, 85% of the maximum output pressure, and 91% of the fractional bandwidth (FBW) can be preserved. A viscoelastic finite element model was also developed and shows the performance effects of the coating can be accurately predicted. Four designs, providing acoustic crosstalk suppression, flexible substrate, lens focusing, and blood flow monitoring using PDMS layer were also demonstrated. The second part of the work, presents contributions towards the electronic integration and packaging of large-area 2-D arrays. A very large 2D array is appealing for it can enable advanced novel imaging applications, such as a reconfigurable array, and a compression plate for breast cancer screening. With these goals in mind, I developed the first large-scale fully populated and integrated 2D CMUTs array with 32 by 192 elements. In this study, I demonstrate a flexible and reliable integration approach by successfully combining a simple UBM preparation technique and a CMUTs-interposer-ASICs sandwich design. The results show high shear strength of the UBM (26.5 g), 100% yield of the interconnections, and excellent CMUT resonance uniformity ([lowercase Sigma] = 0.02 MHz). As demonstrated, this allows for a large-scale assembly of a tile-able array by using an interposer. Interface engineering is crucial towards the development of CMUTs into a practical ultrasound system. With the advances in encapsulation technique with a viscoelastic polymer and the combination of the UBM technique to the TSV fabrication for electronics integration, a fully integrated CMUT system can be realized.

This updated guide to the current state-of-the-art of this complex and multidisciplinary area fills an urgent need for a unified source of information on piezoelectric devices and their astounding variety of existing and emerging applications. New understandings underlying the principles of Piezoelectric Transducers, new technological advances in its applications, and new areas of utility for these transducers made a second edition of this book inevitable.

Ultrasonic Methods of Non-Destructive Testing covers the basic principles and practices of ultrasonic testing, starting with the basic theory of vibration and propagation, design and properties and probes, and then proceeding to the principles and practice of the various ultrasonic techniques for different types of components and structures, both metallic and non-metallic. The design and operation of various types of equipment are covered and references to appropriate national and international standards are provided. Numerous applications are discussed comprehensively and special attention is paid to latest developments. A large number of references is provided so as to enable the reader to obtain further information.

This collection of 32 major review papers provides a complete understanding of the physics of piezoelectricity. With a thorough overview of applications and a major section exploring measurements and standards, this volume gives a systematic derivation of piezoelectric coefficients and equations of state for coupling mechanical, electrical, and thermal fields. A useful graduate text for design engineers, materials scientists, chemists, metallurgists, and condensed matter physicists.

Focusing on the theory and state-of-the-art technologies of ultrasonic testing (UT), this book examines ultrasonic propagation in solids and its detection applications, and explores the intersection of UT technology with various fields of electromagnetics, optics and physics. UT is one of the most widely used nondestructive testing techniques due to its high performance in terms of detection efficiency and safety. The rapid development of modern industrial products and technologies has created a new challenge and demand for ultrasonic nondestructive testing technology. This book introduces the fundamentals of UT, including sound wave and sound field, interface wave theory and liquid-solid coupled sound field. It then discusses various types of UT methods, ranging from the critically refracted longitudinal wave method to ultrasonic surface wave and ultrasonic guided wave detection methods. Some newly developed UT techniques are also discussed, including phased-array UT, high-frequency UT and non-contact UT. This title will appeal to engineering students and technicians in the field of ultrasonic nondestructive testing.

This book contains 67 papers presented at ICTCA2001. It includes three keynote addresses surveying the frontier developments in computational and theoretical acoustics. The papers cover aero-, seismo- and ocean acoustics, as well as ultrasonics. Computational methods, numerical simulation, theoretical analysis and experimental results are emphasized by different papers.The proceedings have been selected for coverage in: Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)