**Meet the editor**

Dr. Marco G. Beghi graduated in 1979 in Nuclear Engineering at Politecnico di Milano, Italy. He spent one year at University of California, Los Angeles. In 1984 he became research fellow at the Department of Nuclear Engineering, Politecnico di Milano, and in 2003 associate professor of Condensed Matter Physics. He was member of government bodies of Politecnico: Board of Adminis-

trators and Academic Senate. Presently he is in the Micro- and Nanostructured Materials Laboratory of the Department of Energy, Politecnico. Since 1991 he has been teaching Experimental Physics, Condensed Matter Physics, and Technology of Nuclear Materials, to undergraduate and graduate students of Nuclear and Materials Engineering. His experimental research concerns the physics of materials. He analyzed the mechanical behavior of metals in terms of dislocation dynamics and irreversible thermodynamics. He then worked on thin films and their properties, exploiting Brillouin spectrometry to measure the elastic properties. He co-authored over seventy peer reviewed publications.

Contents

**Preface IX** 

Kuo-Ming Lee

**Section 1 Analyses and Models of Basic Phenomena 1** 

**in the Vicinity of Nonpiezoactive Directions 3**  V.I. Alshits, V.N. Lyubimov and A. Radowicz

**in a Perfect and Deformed Single Crystals 49** 

Chapter 1 **Electric Components of Acoustic Waves** 

Chapter 2 **Crack Detecting via Newton's Method 33** 

E. Raitman, V. Gavrilov and Ju. Ekmanis

Chapter 4 **Enhanced Transmission of Acoustic Waves Through Subwavelength Holes in Hard Plates 73** 

**in Surface Semiconductor Investigations** 

Chapter 6 **Transient Acoustic Wave Propagation in Porous Media 127** 

Chapter 7 **Utilizing Malaysian Natural Fibers as Sound Absorber 161**  Mohammad Hosseini Fouladi, Mohamed H. Nassir, Masomeh Ghassem, Marwan Shamel, Sim Yeng Peng, Sin Yi Wen, Pang Zong Xin and Mohd Jailani Mohd Nor

Marian Urbańczyk and Tadeusz Pustelny

Zine El Abiddine Fellah, Mohamed Fellah

Chapter 3 **Neutron Diffraction on Acoustic Waves** 

Bo Hou and Weijia Wen

Chapter 5 **The Application of Surface Acoustic Waves** 

**Section 2 Measurement Techniques 89** 

**and Gas Sensors 91** 

and Claude Depollier

## Contents

### **Preface XIII**


Sin Yi Wen, Pang Zong Xin and Mohd Jailani Mohd Nor


Contents VII

**Section 5 Technological Systems 419** 

J.B. David and D. Belot

Chapter 20 **Acoustics and Vibro-Acoustics** 

**Section 7 Acoustics in the Oceans 557** 

Chapter 22 **Underwater Acoustics Modeling**

Jens M. Hovem

Chapter 18 **Techniques for Tuning BAW-SMR Resonators** 

Jerzy Filipiak and Grzegorz Steczko

**Applied in Space Industry 479** Rogério Pirk, Carlos d´Andrade Souto,

J. K. Luo, Y. Q. Fu and W. I. Milne

**in Finite Depth Shallow Waters 559**

and João Batista Carvalho Filardi

**Section 6 Acoustic Waves in Microfluidics 513** 

M. El Hassan, E. Kerherve, Y. Deval, K. Baraka,

Chapter 19 **Seismic Vibration Sensor with Acoustic Surface Wave 443**

Chapter 21 **Acoustic Wave Based Microfluidics and Lab-on-a-Chip 515**

Emerson de Sousa Costa, Eduardo Bauzer Medeiros

Chapter 23 **Ray Trace Modeling of Underwater Sound Propagation 573** 

**for the 4th Generation of Mobile Communications 421** 

Gustavo Paulinelli Guimarães and Luiz Carlos Sandoval Góes

Chapter 17 **Acoustics in Optical Fiber 401**  Abhilash Mandloi and Vivekanand Mishra

### **Section 5 Technological Systems 419**

VI Contents

Chapter 8 **An Investigation of an Acoustic Wave Velocity** 

**and in Plane Sources 171** 

and Soffian Noor Mat Saliah

Pasquale Vena and Marco G. Beghi

**Section 3 Modeling Methods for Microdevices 211** 

T. Laroche and S. Ballandras

**Devices with Bragg Cell 265**  Yongqiang Guo and Weiqiu Chen

**Section 4 Design and Fabrication of Microdevices 295** 

Chapter 13 **High-Overtone Bulk Acoustic Resonator 297** 

V. Pétrini and S. Ballandras

Eric Kerhervé

Sergey E. Babkin

Chapter 17 **Acoustics in Optical Fiber 401**

T. Baron, E. Lebrasseur, F. Bassignot, G. Martin,

Chapter 14 **Modeling and Design of BAW Resonators and Filters for Integration in a UMTS Transmitter 323**

Chapter 15 **Surface Acoustic Wave Based Magnetic Sensors 355**  Bodong Li, Hommood Al Rowais and Jürgen Kosel

Chapter 16 **Electromagnetic and Acoustic Transformation of Surface** 

Abhilash Mandloi and Vivekanand Mishra

Matthieu Chatras , Stéphane Bila, Sylvain Giraud, Lise Catherinot,

Antoine Frappé, Bruno Stefanelli, Andreas Kaiser, Andreia Cathelin, Jean Baptiste David, Alexandre Reinhardt, Laurent Leyssenne and

**Acoustic Waves and Its Application in Various Tasks 381** 

Ji Fan, Dominique Cros, Michel Aubourg, Axel Flament,

Chapter 10 **On Universal Modeling** 

**in a Reinforced Concrete Beam from Out-of Plane** 

Noorsuhada Md Nor, Norazura Muhamad Bunnori, Azmi Ibrahim, Hamidah Mohd Saman, Shahiron Shahidan

Chapter 9 **Combination of Acoustic Methods and the Indentation** 

**of the Bulk Acoustic Wave Devices 213**

Chapter 11 **Progress in Theoretical and Numerical Tools Devoted to** 

Boris Sveshnikov, Sergey Nikitov and Sergey Suchkov

**Understanding of Acoustic Devices Behavior 241** 

Chapter 12 **Precise Analysis and Design of Multi-Layered Acoustic Wave** 

**Technique for the Measurement of Film Properties 189** Fabio Di Fonzo, Francisco García Ferré, Dario Gastaldi,

	- **Section 6 Acoustic Waves in Microfluidics 513**

Preface

behavior.

Acoustics is a mature field which also enjoys a never ending youth. After centuries of investigations, innovations and new developments either come from the endless search for a deeper understanding, and for aspects or phenomena which have not yet been put in light, or are triggered by technological innovations. New technologies can involve phenomena which are known, but which happen in unprecedented conditions, or which need a description of unprecedented accuracy and precision. In particular, the availability of new production technologies leads to the introduction of new devices. In the last years the development of micro-fabrication technologies marked a major step. A whole new class of microdevices, which exploit acoustic waves for various tasks, was introduced and is rapidly growing. Acoustics based microdevices are being developed, in particular, for information processing purposes and for sensing purposes, and have become a key technology in fields like telecommunications. This technological breakthrough challenges the methods for modelling the behavior of acoustic waves: the quest for devices of ever improving performances can be faced only by modelling tools which become more accurate and more detailed, and able to cope with more complex configurations. At the same time, technological developments are sought for the fabrication of these devices, and for their integration in technological systems. Several chapters of this book deal with the modelling and fabrication techniques for microdevices, including the exploration of

But the microdevices field is only one of the research lines in acoustics. The present book offers a sampling which, far from being exhaustive, allows to appreciate how diverse and pervasive the applications of acoustic waves can be. Theoretical analyses are presented, as well as modelling techniques, resulting in a deeper understanding of phenomena or features ranging from the detection of cracks to the acoustics of the oceans. And measurement methods are discussed, which exploit the potential of acoustic waves as probes to investigate the properties of widely different materials and systems. Overall, it is possible to appreciate the huge range of involved length and time scales, and of media supporting acoustic excitations: from the sub-micrometric layers exploited in microdevices to propagation in the oceans, and from materials and configurations aiming at enhancing resonances, to those aiming instead at a damping

unconventional phenomena, configurations and applications.

## Preface

Acoustics is a mature field which also enjoys a never ending youth. After centuries of investigations, innovations and new developments either come from the endless search for a deeper understanding, and for aspects or phenomena which have not yet been put in light, or are triggered by technological innovations. New technologies can involve phenomena which are known, but which happen in unprecedented conditions, or which need a description of unprecedented accuracy and precision. In particular, the availability of new production technologies leads to the introduction of new devices. In the last years the development of micro-fabrication technologies marked a major step. A whole new class of microdevices, which exploit acoustic waves for various tasks, was introduced and is rapidly growing. Acoustics based microdevices are being developed, in particular, for information processing purposes and for sensing purposes, and have become a key technology in fields like telecommunications. This technological breakthrough challenges the methods for modelling the behavior of acoustic waves: the quest for devices of ever improving performances can be faced only by modelling tools which become more accurate and more detailed, and able to cope with more complex configurations. At the same time, technological developments are sought for the fabrication of these devices, and for their integration in technological systems. Several chapters of this book deal with the modelling and fabrication techniques for microdevices, including the exploration of unconventional phenomena, configurations and applications.

But the microdevices field is only one of the research lines in acoustics. The present book offers a sampling which, far from being exhaustive, allows to appreciate how diverse and pervasive the applications of acoustic waves can be. Theoretical analyses are presented, as well as modelling techniques, resulting in a deeper understanding of phenomena or features ranging from the detection of cracks to the acoustics of the oceans. And measurement methods are discussed, which exploit the potential of acoustic waves as probes to investigate the properties of widely different materials and systems. Overall, it is possible to appreciate the huge range of involved length and time scales, and of media supporting acoustic excitations: from the sub-micrometric layers exploited in microdevices to propagation in the oceans, and from materials and configurations aiming at enhancing resonances, to those aiming instead at a damping behavior.

The first section of the book aims at a detailed theoretical exploration, also by sophisticated mathematical analyses, of various aspects of phenomena whose basic laws are well established. Alshits and co-workers present a very deep analysis of the configuration of the vector fields which describe the electrical state in piezoelectric media. In particular, they investigate the fields associated to bulk acoustic wave, showing the existence of non piezoactive directions and analyzing the effect of symmetries. Lee undertakes a rigorous analysis of a scattering phenomenon which is the basis of a widespread non destructive examination technique: the scattering of an acoustic wave by a crack. Lee considers the direct problem, the computation of the acoustic field scattered by a crack of known size and shape, then investigates the inverse problem: how accurately can a crack be reconstructed, from the acoustic waves scattered by it? Raitman et al. exploit the dynamical scattering theory to investigate the effect of the acoustic waves on the observed diffraction patterns. They achieve a detailed interpretation of various features, experimentally observed. Hou & Wen present an analysis, both theoretical and experimental, of the peculiar transmission properties of a plate containing sub wavelength holes, or arrays of holes. They give a detailed picture of various regimes, and of underlying phenomena like evanescent waves.

Preface XI

like energy balance, the second law of thermodynamics, and reciprocity. Laroche & Ballandras summarize a development work that was pursued for over a decade, until the integration of different techniques, namely Finite Elements Analysis, Boundary Elements Method and Perfectly Matched Layer method. This wide modelling effort led to the selection of the most appropriate tool for each aspect of the simulation, and results in a modelling tool which can treat both bulk waves and surface waves microdevices. Guo & Chen present a new version of the analytical method of reverberation-ray matrix, devoted to the integrated analysis of film bulk acoustic wave resonators (FBARs) with an underlying Bragg Cell which decouples the resonator

Chapters in the fourth section present design and development efforts which led to the fabrication of microdevices. Baron et al. report the development work which led to bulk acoustic resonators, in particular operating in the high overtone mode. The microfabrication technologies are addressed, and the behavior of the resonators is characterized. The exploitation of these resonators for the realization of devices of various types, like oscillators, sensors, wireless sensors is reviewed, including the detailed characterization of aspects like temperature compensation. Chatras and coworkers give a complete account of the whole process of design, prototype realization and testing of electronic devices based on bulk acoustic waves, including the characterization of the overall performance in terms of signal processing. The whole process shows how crucial the bulk acoustic wave based devices can be for the development of hardware meeting the requirements of last generation mobile radio (the UMTS standard). The importance of the analysis of the acoustic behavior for the optimization of the performance also emerges. Li et al., after a more general discussion of SAW based sensors, in particular of magnetic field sensors, discuss a recent development: the design, fabrication and characterization of an integrated SAW based passive sensor (a transponder) for magnetic field, which exploits a giant magnetoimpedance effect. Babkin discusses a peculiar method for the conversion between electromagnetic and acoustic energy, which is the basis of both the excitation and the detection of acoustic waves. Conversion by piezoelectric materials is widely adopted; Babkin discusses instead the conversion by magnetic means. Some devices are presented, including devices for the analysis of materials and of their defects. Mishra demonstrates the performance of in-fiber optical devices obtained coupling fibers of different thicknesses with a piezoelectric transducer driven by a RF generator. The acoustic energy is efficiently transferred to the fiber by a machined aluminum horn, and by the acousto-optic effects tunable filters are obtained, whose performance

The fifth section addresses the integration of acoustic based devices into more complex engineered systems. El Hassan et al. consider FBARs and Solidly Mounted Resonators (SMRs), equipped with passive elements (capacitances and inductances), and demonstrate a tunable BAW-SMR filter which matches the requirements for mobile communications (the WLAN 802.11 b/g standard). Furthermore, a digitally tunable

behavior from that of the substrate.

is characterized and optimized.

The second section presents the exploitation of acoustic waves in the implementation of measurement techniques. Urbanczyk offers a wide review of measurement techniques and devices based on surface acoustic wave (SAWs). Fellah et al. consider the propagation of transient acoustic waves in a homogeneous isotropic slab of porous material, having a rigid or an elastic frame. Taking into account the inertial, viscous and thermal losses of the medium, they presents a model of the direct and inverse scattering problem. This analysis suggests several characterization methods based on the inverse problem, using experimental data of reflected and/or transmitted waves. These methods were validated experimentally on samples of air saturated porous materials, and are useful for materials like bone tissue. Hosseini Fouladi et al. focus on Malaysian Natural Fibers exploited as sound absorbers. They give a comparative characterization of various types of fibers. Md Nor and co-workers focus instead on the measurement of acoustic velocities in reinforced concrete beams: such velocities are a required input in the analysis of non destructive tests. Di Fonzo et al. consider the mechanical characterization of thin films, and show how the results obtained by acoustic techniques can be usefully improved by the joint exploitation of a completely different technique, indentation.

The third section addresses the techniques developed for an accurate modelling of the behavior of acoustics based microdevices. Sveshnikov presents a highly efficient analytical model, able to describe any multilayer bulk acoustic wave (BAW) device, by a flexible one-dimensional modeling and a phenomenological consideration of dissipation. The model can treat structures with an arbitrary number and sequence of dielectric and metal layers, as well as multiple electrodes. To verify the validity of any simulation, an original integral method is proposed, based on fundamental principles like energy balance, the second law of thermodynamics, and reciprocity. Laroche & Ballandras summarize a development work that was pursued for over a decade, until the integration of different techniques, namely Finite Elements Analysis, Boundary Elements Method and Perfectly Matched Layer method. This wide modelling effort led to the selection of the most appropriate tool for each aspect of the simulation, and results in a modelling tool which can treat both bulk waves and surface waves microdevices. Guo & Chen present a new version of the analytical method of reverberation-ray matrix, devoted to the integrated analysis of film bulk acoustic wave resonators (FBARs) with an underlying Bragg Cell which decouples the resonator behavior from that of the substrate.

X Preface

waves.

different technique, indentation.

The first section of the book aims at a detailed theoretical exploration, also by sophisticated mathematical analyses, of various aspects of phenomena whose basic laws are well established. Alshits and co-workers present a very deep analysis of the configuration of the vector fields which describe the electrical state in piezoelectric media. In particular, they investigate the fields associated to bulk acoustic wave, showing the existence of non piezoactive directions and analyzing the effect of symmetries. Lee undertakes a rigorous analysis of a scattering phenomenon which is the basis of a widespread non destructive examination technique: the scattering of an acoustic wave by a crack. Lee considers the direct problem, the computation of the acoustic field scattered by a crack of known size and shape, then investigates the inverse problem: how accurately can a crack be reconstructed, from the acoustic waves scattered by it? Raitman et al. exploit the dynamical scattering theory to investigate the effect of the acoustic waves on the observed diffraction patterns. They achieve a detailed interpretation of various features, experimentally observed. Hou & Wen present an analysis, both theoretical and experimental, of the peculiar transmission properties of a plate containing sub wavelength holes, or arrays of holes. They give a detailed picture of various regimes, and of underlying phenomena like evanescent

The second section presents the exploitation of acoustic waves in the implementation of measurement techniques. Urbanczyk offers a wide review of measurement techniques and devices based on surface acoustic wave (SAWs). Fellah et al. consider the propagation of transient acoustic waves in a homogeneous isotropic slab of porous material, having a rigid or an elastic frame. Taking into account the inertial, viscous and thermal losses of the medium, they presents a model of the direct and inverse scattering problem. This analysis suggests several characterization methods based on the inverse problem, using experimental data of reflected and/or transmitted waves. These methods were validated experimentally on samples of air saturated porous materials, and are useful for materials like bone tissue. Hosseini Fouladi et al. focus on Malaysian Natural Fibers exploited as sound absorbers. They give a comparative characterization of various types of fibers. Md Nor and co-workers focus instead on the measurement of acoustic velocities in reinforced concrete beams: such velocities are a required input in the analysis of non destructive tests. Di Fonzo et al. consider the mechanical characterization of thin films, and show how the results obtained by acoustic techniques can be usefully improved by the joint exploitation of a completely

The third section addresses the techniques developed for an accurate modelling of the behavior of acoustics based microdevices. Sveshnikov presents a highly efficient analytical model, able to describe any multilayer bulk acoustic wave (BAW) device, by a flexible one-dimensional modeling and a phenomenological consideration of dissipation. The model can treat structures with an arbitrary number and sequence of dielectric and metal layers, as well as multiple electrodes. To verify the validity of any simulation, an original integral method is proposed, based on fundamental principles

Chapters in the fourth section present design and development efforts which led to the fabrication of microdevices. Baron et al. report the development work which led to bulk acoustic resonators, in particular operating in the high overtone mode. The microfabrication technologies are addressed, and the behavior of the resonators is characterized. The exploitation of these resonators for the realization of devices of various types, like oscillators, sensors, wireless sensors is reviewed, including the detailed characterization of aspects like temperature compensation. Chatras and coworkers give a complete account of the whole process of design, prototype realization and testing of electronic devices based on bulk acoustic waves, including the characterization of the overall performance in terms of signal processing. The whole process shows how crucial the bulk acoustic wave based devices can be for the development of hardware meeting the requirements of last generation mobile radio (the UMTS standard). The importance of the analysis of the acoustic behavior for the optimization of the performance also emerges. Li et al., after a more general discussion of SAW based sensors, in particular of magnetic field sensors, discuss a recent development: the design, fabrication and characterization of an integrated SAW based passive sensor (a transponder) for magnetic field, which exploits a giant magnetoimpedance effect. Babkin discusses a peculiar method for the conversion between electromagnetic and acoustic energy, which is the basis of both the excitation and the detection of acoustic waves. Conversion by piezoelectric materials is widely adopted; Babkin discusses instead the conversion by magnetic means. Some devices are presented, including devices for the analysis of materials and of their defects. Mishra demonstrates the performance of in-fiber optical devices obtained coupling fibers of different thicknesses with a piezoelectric transducer driven by a RF generator. The acoustic energy is efficiently transferred to the fiber by a machined aluminum horn, and by the acousto-optic effects tunable filters are obtained, whose performance is characterized and optimized.

The fifth section addresses the integration of acoustic based devices into more complex engineered systems. El Hassan et al. consider FBARs and Solidly Mounted Resonators (SMRs), equipped with passive elements (capacitances and inductances), and demonstrate a tunable BAW-SMR filter which matches the requirements for mobile communications (the WLAN 802.11 b/g standard). Furthermore, a digitally tunable

#### XVI Preface

BAW-SMR filter implementation is shown. Filipiak & Steczko consider SAW based vibration sensors, characterize their performance and show how they can be integrated into a warning system. Pirk and co-workers focus on a specific case: the payload of space flights. At rocket lift off, and during the subsequent transonic flight, severe acoustic loads are imposed to the payloads. Pirk and co-workers discuss techniques to measure such loads and to model them, aiming at the optimization of acoustic load mitigation measures.

The sixth section is devoted to the applications of acoustic waves into microfluidic devices. Luo et al. give an extensive overview of how acoustic waves can be exploited to perform various tasks, including manipulation of droplets and mixing of liquids.

On a completely different length scale, the seventh section is devoted to the acoustics of the oceans. De Sousa Costa & Bauzer Medeiros introduce the reader into the field, offering a synthetic and comparative overview of the modelling methods for acoustic propagation in the oceans, in which reflection phenomena at the surface and at the underlying interface with rocks or sediments have an important role. Hovem focuses on the ray tracing method. He shows the effects of the depth dependent, and season dependent, properties of water, which cause curved trajectories of individual rays. He also gives a detailed modelling of the reflection at the interface between the water and the underlying sediment layer.

As mentioned above, this book offers a representative sampling of the wide horizon of present research in acoustics. It includes, on one side, deep theoretical and numerical analyses of specific phenomena and devices, and, on the other side, more technically oriented contributions, which show the usefulness of acoustics based devices in building engineered systems. The book is therefore of interest for both the specialized reader, who can find deep insights into some specific topic, and for a more general readership, who, by exploring a wide variety of ideas and of approaches, can find interesting suggestions.

> **Marco G. Beghi** Politecnico di Milano, Energy Department and NEMAS Center, Milano, Italy

**Analyses and Models of Basic Phenomena** 

**Chapter 1** 

© 2013 Alshits et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

© 2013 Alshits et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**Electric Components of Acoustic Waves** 

V.I. Alshits, V.N. Lyubimov and A. Radowicz

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/56067

**1. Introduction** 

applications.

**in the Vicinity of Nonpiezoactive Directions** 

The acoustic wave of displacements in piezoelectric media is usually accompanied by a quasistatic wave of the electric potential. This implies that, using acoustic waves, electric signals can be transmitted over a crystal at the velocity of sound. Such possibility opened the way to numerous applications of acoustic waves in electronic devices and even led to the formation of a special field of science called acoustoelectronics. The applied aspect provides an important stimulus for extensive investigations devoted to various features of acoustic fields in piezoelectric crystals (Royer & Dieulesaint, 2000). These investigations are also stimulated by basic interest in the study of new effects in media with electromechanical couplings (Lyubimov, 1968; Balakirev & Gilinskii, 1982; Lyamov, 1983). The acoustics of piezoelectric crystals is still an extensively developing field of solid state physics [see, e.g., the review article by Gulyaev (1998)], the more so that even purely basic investigations in this field frequently contain ideas for fruitful, however not immediately evident,

It should also be noted that the anisotropy often influences the properties of piezoelectric crystals in a nontrivial way, and may sometimes lead to qualitatively new phenomena. In particular, it is very important from the practical standpoint to know the wave propagation directions **m** for which the electric field components possess maximum amplitudes (Alshits & Lyubimov, 1990) and, on the contrary, to reveal the nonpiezoactive directions (Royer & Dieulesaint, 2000; Lyamov, 1983) in which the electric signals are not transmitted. Taking into account that, irrespective of the anisotropy, the electric field in an acoustic wave is always longitudinal (**E** || **m**) and the electric induction is always transverse (**D m**), we have to distinguish (Lyamov, 1983) between the directions of longitudinal and transverse nonpiezoactivity in which **E** = 0 and **D** = 0, respectively. This paper presents the results of

investigations aimed at a detailed analysis of the nonpiezoactivity of both types.

and reproduction in any medium, provided the original work is properly cited.
