Piezo-Electric Electro-Acoustic Transducers

232 Pages·2014·7.11 MB·English

by  Valeriy Sharapov

Microtechnology and MEMS
Valeriy Sharapov
Zhanna Sotula
Larisa Kunickaya
Piezo-Electric
Electro-Acoustic
Transducers
Microtechnology and MEMS
Series Editors
Professor Dr. Hiroyuki Fujita
Institute of Industrial Science, University of Tokyo, Tokyo, Japan
Professor Dr. Dorian Liepmann
Department of Bioengineering, University of California, Berkley, USA
For furthervolumes:
http://www.springer.com/series/4526
The series Microtechnology and MEMS comprises text books, monographs, and state-of-
the-art reports in the very active field of microsystems and microtechnology. Written by
leading physicists and engineers, the books describe the basic science, device design, and
applications. They willappeal toresearchers, engineers, and advanced students.
Valeriy Sharapov Zhanna Sotula
•
Larisa Kunickaya
Piezo-Electric Electro-
Acoustic Transducers
123
Valeriy Sharapov
Zhanna Sotula
Larisa Kunickaya
Department of Instrument-Making
Cherkasy StateTechnological University
Cherkasy
Ukraine
ISSN 1615-8326
ISBN 978-3-319-01197-4 ISBN 978-3-319-01198-1 (eBook)
DOI 10.1007/978-3-319-01198-1
SpringerChamHeidelbergNewYorkDordrechtLondon
LibraryofCongressControlNumber:2013947377
(cid:2)SpringerInternationalPublishingSwitzerland2014
Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof
the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,
recitation,broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionor
informationstorageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilar
methodology now known or hereafter developed. Exempted from this legal reservation are brief
excerpts in connection with reviews or scholarly analysis or material supplied specifically for the
purposeofbeingenteredandexecutedonacomputersystem,forexclusiveusebythepurchaserofthe
work. Duplication of this publication or parts thereof is permitted only under the provisions of
theCopyright Law of the Publisher’s location, in its current version, and permission for use must
always be obtained from Springer. Permissions for use may be obtained through RightsLink at the
CopyrightClearanceCenter.ViolationsareliabletoprosecutionundertherespectiveCopyrightLaw.
The use of general descriptive names, registered names, trademarks, service marks, etc. in this
publicationdoesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexempt
fromtherelevantprotectivelawsandregulationsandthereforefreeforgeneraluse.
While the advice and information in this book are believed to be true and accurate at the date of
publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor
anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with
respecttothematerialcontainedherein.
Printedonacid-freepaper
SpringerispartofSpringerScience+BusinessMedia(www.springer.com)
Preface
Thisbookpresentsthelatestandcompleteinformationaboutpiezoelectricelectro-
acoustic transducers.
Electro-acoustic transducer (EAT) is a device which transforms electrical
energy to energy of acoustic fluctuations. Principles of action, the designs of
knowntransducersforworkinair,water,fornondestructivecontrolaredescribed
inthebook.Thesetransducersarebasedonbackpiezoelectriceffectsthatareused
in electro-acoustics, the hydroacoustics, and nondestructive control.
Offeredto«Springer»thebookconsistsoffivesemantic(sense,meaning)parts:
The general information about PEAT, terms and definitions, materials, the
description of piezoelements, etc.
The description of known designs PEAT for work in air, water, and with firm
bodies.
New methods and devices electrophysical and circuit engineering designing
(synthesis, creation) of piezoelectric electro-acoustic transducers and sensors are
described. Application of these methods allows to create from one piezoelement
tens (!) variants of transducers and sensors of the given type with various,
including, improved characteristics.
New methods and devices for improvement of characteristics PEAT are
described: reduction of working frequency that is equivalent to increase range of
action (range of detection of sea objects), increases in sound pressure and pass-
band expansion (for underwater communication), etc. These methods allow to
create transducers with unique properties.
Thisbookiswrittennotonlyforspecialistsinelectro-acoustics,hydroacoustics,
nondestructive control, measuring technique, sensors for automatic control, but
also for graduate students.
The authors are thankful to Senior Editor Springer Dr. Claus Ascheron for the
qualified consideration of the manuscript, benevolent support of authors, and
patience at work with them.
Cherkasy, Ukraine Valeriy Sharapov
Zhanna Sotula
Larisa Kunickaya
v
Contents
1 General Information About Electro-Acoustic Transducers. . . . . . . 1
1.1 Terms and Definitions. Classification EAT. . . . . . . . . . . . . . . . 1
1.2 Basic Characteristics PEAT . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Materials for PEAT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Piezoceramic Elements for PEAT. . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1 Fluctuations of Piezoceramic Disk Polarised on a Thickness. . . . 13
2.2 The Fluctuations of Radially Polarised Cylinder . . . . . . . . . . . . 18
2.3 Piezoelectric Resonators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4 Piezoceramic Transformers. . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.5 Bimorph and Trimorph Piezoelements. . . . . . . . . . . . . . . . . . . 26
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3 Electro-Acoustic Transducers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.1 General Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2 Chladni Figures and Transducers Directional Diagrams . . . . . . . 43
3.3 Electro-Acoustic Transducers in Active Oscillators Schemes . . . 48
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4 Hydroacoustic Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.1 Classification and Characteristics. . . . . . . . . . . . . . . . . . . . . . . 57
4.2 Ratios of Electromechanical Transformations . . . . . . . . . . . . . . 59
4.3 Cylindrical Piezoceramic Transducers . . . . . . . . . . . . . . . . . . . 60
4.4 Lamellar and Spherical Piezoceramic Transducers. . . . . . . . . . . 61
4.5 Basic Requirements to Transducers Projected. . . . . . . . . . . . . . 63
4.6 Selection of Energy Transformation Method and Mode Shape . . 64
4.7 Certain Transducers Designs. . . . . . . . . . . . . . . . . . . . . . . . . . 66
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
vii
viii Contents
5 Transducers with Non-Destructive Control. . . . . . . . . . . . . . . . . . 73
5.1 Classification of Methods of Non-Destructive Control. . . . . . . . 73
5.2 Acoustic Methods of Non-Destructive Control . . . . . . . . . . . . . 74
5.3 Piezoelectric Transducers for Non-Destructive Control. . . . . . . . 76
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6 The Technologies of PEAT Synthesis . . . . . . . . . . . . . . . . . . . . . . 91
6.1 Spatial Energy: Force Structure of Piezoceramic Element . . . . . 91
6.2 Spatial Arrangement and Conjunction Piezoelement
Electrodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
6.3 Spatial Electromechanical Feedback . . . . . . . . . . . . . . . . . . . . 99
6.4 Inclusion of Piezoelements in Schemes of Electric Filters . . . . . 104
6.5 Technology of Additional Elements. . . . . . . . . . . . . . . . . . . . . 105
6.6 Technology of Synthesis of the Transducers, Considering
Electric signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
6.7 The Combined Technology. . . . . . . . . . . . . . . . . . . . . . . . . . . 111
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
7 Methods of Low-Frequency Acoustic Vibrations Creation. . . . . . . 115
7.1 Method of Beating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
7.2 Piezoelectric Adders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
7.3 Creating of Low Frequency Oscillations by Means
of Peak Modulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
7.4 Method of Additional Oscillatory Contour . . . . . . . . . . . . . . . . 129
7.5 Creation of LF Acoustic Fluctuations with the Help
of Monomorph Piezoelements. . . . . . . . . . . . . . . . . . . . . . . . . 133
7.6 Creation of LF Fluctuations with Help Bimorph
and Trimorph Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
7.7 Application of Volume Resonators in Electro-Acoustic
Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
8 Methods of Increasing Sound Pressure. . . . . . . . . . . . . . . . . . . . . 147
8.1 Method of Additional Oscillatory Contour . . . . . . . . . . . . . . . . 147
8.2 Internal Friction in Piezoceramic Elements
of Electro-Acoustic Transducers . . . . . . . . . . . . . . . . . . . . . . . 149
8.3 Piezoelectric Projectors of a Sound on a Basis of Bimorph
and Trimorph Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
8.3.1 Decrease of Resonant Frequency . . . . . . . . . . . . . . . . . 155
8.3.2 Increase of Sound Pressure Level . . . . . . . . . . . . . . . . . 156
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Contents ix
9 Methods of Expansion of Pass-Band PEAT. . . . . . . . . . . . . . . . . . 163
9.1 Decrease of Quality of Transducer. . . . . . . . . . . . . . . . . . . . . . 163
9.2 Connected Contours. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
9.3 Volume Resonators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
10 Sensors with Piezoelements in Shemes Electric Filters. . . . . . . . . . 173
10.1 Schemes of Electric Filters. . . . . . . . . . . . . . . . . . . . . . . . . . . 173
10.2 Sensors with Piezoelements in Low-Pass Filters Schemes . . . . . 180
10.3 Sensors with Piezoelements in High-Pass Filters Schemes . . . . . 181
10.4 Sensors with Piezotransformers in Electric Filters Schemes . . . . 181
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
11 Devices to Control and Diagnose Bimorph Piezoelements . . . . . . . 191
11.1 Defects of Bimorph Piezoelements . . . . . . . . . . . . . . . . . . . . . 191
11.2 Defects Diagnostics by AFC. . . . . . . . . . . . . . . . . . . . . . . . . . 192
11.3 Diagnostics of Defects by Pulse Characteristic . . . . . . . . . . . . . 198
11.4 Diagnostics of Defects by Transitive Characteristic. . . . . . . . . . 204
11.5 Devices Based on Active Oscillator Circuit . . . . . . . . . . . . . . . 208
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
About the Authors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Authors’ Patents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Chapter 1
General Information About Electro-Acoustic
Transducers
Abstract The general data about electro-acoustic transducers are resulted in this
chapter.Theirclassification,basiccharacteristics,materialswhichareusedforman-
ufacturingofsuchtransducersaredescribed.
1.1 TermsandDefinitions.Classification EAT
Electro-acoustictransducers(EAT)areintendedfortransformationofelectricenergy
intoacousticsignalandback[1–7].Dependingonatransformationdirectionthere
aredistinguishstrictlyEAT(projectors)andsoundreceivers(sensors)(Fig.1.1).
Electro-acoustic transducers widely use for radiation and sound reception in
communicationtechnicsandsoundreproduction,forradiationandreceptionofelas-
ticfluctuationsintheultrasonictechnics(notdestructivecontrol),inhydroacoustics
(a hydrolocation, underwater communication, sound «lighting» underwater situa-
tion,etc.),inacoustoelectronics(transducersofphysicalsizes,electricfiltersetc.),in
medicine(ultrasonicintroscopy),insystemsofsafety,securitydevicesetc.(Fig.1.2).
InmajorityEATdoubletransformationofenergytakesplace:electromechanical
transformationinwhichresultthepartofelectricenergybroughttothetransducers
passesinenergyoffluctuationsofsomemechanicalsystem,andMechanoacoustic
transformationatwhichfortheaccountoffluctuationsofmechanicalsysteminthe
environmentthesoundfieldiscreated(Fig.1.3).
ThemostwidespreadEATarelinear,i.e.satisfytotherequirementofnotdistorted
signal transmission, and are reversible, i.e. can work both as a radiator and as the
receiver,andsubmittoareciprocityprinciple.
Thereare,however,EAT,nothavingmechanicaloscillatorysystemandcreating
fluctuations in direct in the environment, for example the electrospark projector
raisingintensivesoundfluctuationsasaresultoftheelectricdischargeinaliquid,
a radiator which action is based on electroctriction liquids. These projectors are
irreversibleandareappliedrarely.Soundreceivers(alsoirreversible)basedonchange
V.Sharapovetal.,Piezo-ElectricElectro-AcousticTransducers, 1
MicrotechnologyandMEMS,DOI:10.1007/978-3-319-01198-1_1,
©SpringerInternationalPublishingSwitzerland2014