DOCSLIB.ORG

Piezoelectricity

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Piezoelectricity Piezoelectricity • Polarization does not disappear when the electric field removed. • The direction of polarization is reversible. Polarization saturation Ps Remenent polarization Pr +Vc Voltage Coercive voltage Figure by MIT OCW FRAM utilize two stable positions. Figure by MIT OCW 15 Sang-Gook Kim, MIT Hysterisis ) 2 m c / C µ ( n o i t a z i r a l o P Electric Field (kV/cm) Ferroelectric (P-E) hysteresis loop. The circles with arrows indicate the polarization state of the material for different fields. 16 Sang-Gook Kim, MIT Figure by MIT OCW. Domain Polarization • Poling: 100 C, 60kV/cm, PZT • Breakdown: 600kV/cm, PZT •Unimorphcantilever Sang-Gook Kim, MIT 17 Piezoelectricity Direct effect D = Q/A = dT E = -gT T = -eE Converse effect E = -hS S = dE g = d/ε = d/Kε o • D: dielectric displacement, electric flux density/unit area • T: stress, S: strain, E: electric field • d: Piezoelectric constant, [Coulomb/Newton] Free T d = (∂S/∂E) T = (∂D/∂T) E Boundary Conditions Short circuit E g = (-∂E/∂T) D = (∂S/∂D) T Open circuit D e = (-∂T/∂E)S = (∂D/∂S) E h = (-∂T/∂D) = (-∂E/∂S) Clamped S S D Sang-Gook Kim, MIT 18 Principles of piezoelectric Electric field(E) g β Ele -h c tr ct ε o fe - f th e e c r ri Dielectric m t a Displacement(D) l ec e el f o d fe -e c iez d t P g -e Strain(S) Entropy -h s Stress(T) c Temperature Thermo-elastic effect Sang-Gook Kim, MIT 19 Equation of State Basic equation E d-form Sij = sijkl Tkl+dkijEk cE = 1/sE T E Di = diklTkl+ εik Ek e = dc g-form S = sDT+gD E T E ε = ε -dc dt T E = -gT+ β D βT = 1/εT E T e-form Tij = cijkl Skl-ekijEk g = d/ε D = e S + ε SE D E T -1 i kij kl ik k s = s -dt(ε ) d h-form T = cDS-hD D = Q/A E = -hS+βSD S = F/A Sang-Gook Kim, MIT 20 Equation of states D = dT + ε T E S = s ET + dE direct converse Tensor to Matrix notation For cylindrical symmetry, and poling in axis 3, D1 = ε1 E1 + d15T5 3 D 2 = ε1 E 2 + d15T4 D = ε E + d (T + T ) + d T 3 3 3 31 1 2 33 3 6 S = s T + s T + s T + d E 2 1 11 1 12 2 13 3 31 3 5 4 S2 = s11T2 + s12T1 + s13T3 + d 31 E 3 1 S3 = s13 (T1 + T2 ) + s33T3 + d 33 E 3 S4 = s 44T4 + d15 E 2 S5 = s 44T5 + d15 E1 S6 = s66T6 Sang-Gook Kim, MIT 21 Applications of piezoelectric Pressure sensors Sensors Accelerometers Gyroscopes Power generators Vibrators Ultrasonic transducers Resonators / Filters / Switches Actuators Surface Acoustic wave(SAW) devices Transformers Actuators Ultrasonic motors Sang-Gook Kim, MIT 22 Piezoelectric Charge Constants Electrical energyActuator Mechanical energy Longitudinal (d33) Transverse (d31) Shear (d15) Diagram removed for copyright reasons. Diagram removed for copyright reasons. Source: Piezo Systems, Inc. Source: Piezo Systems, Inc. "Introduction to Piezo Transducers." "Introduction to Piezo Transducers." E P http://www.piezo.com/bendedu.html http://www.piezo.com/bendedu.html ΔL/L = d31 ·E Shear strain ∆T/T = d33 ·E = d15 E Sang-Gook Kim, MIT 23 Piezoelectric Charge Constants Mechanical energySensor Electrical energy Longitudinal (d33) Transverse (d31) Multi-layer (d33) Diagram removed for copyright reasons. Diagram removed for copyright reasons. Diagram removed for copyright reasons. Source: Piezo Systems, Inc. Source: Piezo Systems, Inc. Source: Piezo Systems, Inc. "Introduction to Piezo Transducers." "Introduction to Piezo Transducers." http://www.piezo.com/bendedu.html "Introduction to Piezo Transducers" http://www.piezo.com/bendedu.html http://www.piezo.com/bendedu.html Q = d ·F Q = d33 ·Fin 31 in Q = n ·d33 ·Fin Vout/T = g33 ·Fin /(L · W) Vout /T= g31 ·Fin/(T · W) Vout /T= t/n · g33 ·Fin /(LW) 24 Sang-Gook Kim, MIT d31 vs d33 Homework 2: Compare generated voltages V31 (from d31mode), V33 (d33mode). Both have same cantilever dimension, but different electrodes. Assume, g33=2g31 tpzt=o.5 µ d=5 µ d33=200 pC/n length=100 µ, width=50 µ K=1000 Young’s modulus of the beam= 65 Gpa, max. strain = 0.1% Interdigitated Electrode + - + - + - + PZT layer P ZrO2 layer Membrane layer Sang-Gook Kim, MIT 25 Design of a Z-positioner Component schematic removed for copyright reasons. Physik Instrumente Z-positioner P-882.10, in http://www.pi-usa.us/pdf/2004_PICatLowRes_www.pdf, page 1-45. Ordering Number* Dimensions Nominal Max. Blocking Stiffness Electrical Resonant A x B x L Displaceme Displaceme Force [N @ [N/µm] Capacitance Frequency [mm] nt [µm @ nt [µm @ 120 V] [µF] (±20%) [kHz] 100 V] 120 V] (±10%) (±10%) P-882.10 2 x 3 x 9 7 9 215 26 0.13 135 Sang-Gook Kim, MIT 26 Sang-Gook Kim, MIT Kim, Sang-Gook Fabrication Methods for PZT thin Films thin PZT for Methods Fabrication o Annealing temperature ( C ) 1200 600 0.02 Laser ablation Laser Sputtering, CVD or CVD Film Thickness (um) Thickness Film Sol-gel 1 deposition Screen printing Screen Gas-jet Gas-jet . 100 27 Sol-Gel spin coating Advantages • Vacuum chamber not necessary (simple) • Easy composition control • Deposition on large flat substrate Disadvantages • Difficult to deposit on deep trenched surface • Higher raw material consumption Sang-Gook Kim, MIT 28 Advantage and disadvantage of PZT film Advantage Disadvantage Unlimited resolution Complex fabrication Large force generation Hysteresis Fast expansion Life cycle (1012 cycles) No magnetic fields (low cross talk) ; Fatigue, retention… Low power consumption No wear and tear for actuation Vacuum and clean room compatible Operation at cryogenic temperature Sang-Gook Kim, MIT 29 Typical Layer Structures for Sol-Gel PZT Top electrode Pt (e-beam evaporation lift-off) Piezoelectric PZT (sol-gel spinning) Bottom electrode Pt/Ti (e-beam evaporation lift-off) Diffusion barrier SiO2 or SiNx (CVD) Diffusion barrier ZrO2(sol-gel spinning) Si substrate Si substrate d31 mode d33 mode Sang-Gook Kim, MIT 30 Thermal Oxide Growth and Bottom Electrode Evaporation Tubes for growing of device diffusion barrier Evaporation of device electrodes Sang-Gook Kim, MIT Photos: MIT Microsystems Technologies Laboratory 31 Fabrication of the PZT Film PZT Sol material 18% PbO excess PZT (52/48) At 500 rpm for 3sec Spin coating and at 3000 rpm for 30sec Drying At 350°C for 5 min. (hot plate) Annealing At 650°C for 15 min. (box furnace) HCl(64%)+BOE(31%)+DI (5%) Wet etching (0.25 µm/min) Spin-coat Mitsubishi PZT sol-gel: 15% PZT(118/52/48) A6 Type Sang-Gook Kim, MIT 32 Fabrication of the PZT Film Spin coater PZT Sol material PZT sol Spin coating Drying Annealing Wet etching Annealing furnace Sang-Gook Kim, MIT Photo: MIT Microsystems Technologies Laboratory 33 PZT Patterning Patterned PZT on device PZT PZT bottom electrode bottom electrode cantilever gratings top electrode thin-film PZT bottom electrode Sang-Gook Kim, MIT 34 PZT Patterning (Wet ethcing) PZT wet-etching with thick photoresist photoresist PZT film Membrane and eletrode Silicon substrate 5 µm photoresist 688 nm 256 nm PZT layer Pt/Ta layer silicon substrate HCl(64%)+BOE(31%)+DI (5%) (etch rate: 0.25 µm/min) Sang-Gook Kim, MIT 35 PZT Patterning (Wet ethcing) PZT wet-etching with thin resist photoresist PZT film Membrane and eletrode Silicon substrate photoresist residual PZT open region • large undercuts with thin (1 µm) photoresist material 1 W. Liu et al, Thin Solid Films, 2000. 2 K. Yamashita et al,Transducers ‘01, Munich. Sang-Gook Kim, MIT 36 PZT Patterning (Dry etching) PZT dry-etching with thick resist photoresist PZT film Membrane and eletrode Silicon substrate using RIE, Plamaquest (in TRL) or Plasmatherm (in EML) with BCl3:Cl2 (30:10) • stiff sidewall with thick (10 µm) photoresist material Sang-Gook Kim, MIT 37 Top Electrode Lift-Off cantilever doubly-hinged membrane d33 mode interdigitated structure bottom electrode top electrode thin-filmperforated PZT membrane PZT undercut close-up on multi-layers 100 um d31 mode sandwich structure Pt/Ti top electrode pattern by lift-off, 220 nm thick. Sang-Gook Kim, MIT 38 Micro-structure of PZT Thin Film SEM of PZT film surface Cross sectional image of PZT film Average grain size : 0.1µm PZT thickness = 510 ± 40 nm; Pt thickness = 200 nm. Using SEM Sang-Gook Kim, MIT 39 PZT XRD On Various Bottom Electrode Combinations Pt(111) PZT(011) PZT/Pt/Ti/SiNx - no hillocks PZT(111) PZT(112) PZT(001) PZT(002) PZT(102) Cu Kβ Pt(002) PZT/Pt/Ti/SiO2 - no hillocks Pyrochlore PZT/Pt(annealed)/Ta/SiO2 - a few hillocks Intensity (A.U.) Intensity Pyrochlore PZT/Pt(no annealed)/Ta/SiO2 - many hillocks W Lα 20 30 40 50 60 Using XRD 2θ Sang-Gook Kim, MIT 40 Electrical Measurements - PZT Ferroelectric Characterization 80 P 60 s ) 40 2 20 C/cm µ 0 2P r -20 2 Area:260x260 µm ε =1172, tanδ=0.04 -40 2 P =65µC/cm s 2 Polarization ( Polarization 2P =50µC/cm -60 r V =3V (E =60KV/cm) V c c -80 c -20 -15 -10 -5 0 5 10 15 20 Using RT-66A Applied voltage (V) • hysteresis due to domain reorientation - growth, merging and shrinkage 2 • saturation polarization, Ps at 65 µC/cm 2 • remnant polarization, 2Pr at 50 µ C/cm Sang-Gook Kim, MIT 41 Piezoelectric Fatigue Analysis PZT characteristics against number of cycles 120 100 1.5E10 cycles 80 3.1E10 cycles 60 value 40 1st run 3.9E10 cycles 2nd run 20 5V-19.6µs-rectangular pulse-train Percentage initial change from dons-d14F 0 1.E+04 1.E+06 1.E+08 1.E+10 1.E+12 Using RT-66A fatigue cycles • PZT electrical fatigue up to more than 1E10 cycles • characteristics recovered on 2nd run with same device Sang-Gook Kim, MIT 42 Piezoelectric Displacement Analysis 0.035 Saturation voltage ~ +/- 15V ) 0.03 0.025 0.02 0.015 0.01 measurement corresponding 0.005 predictions Estimated membrane strain (% membrane strain Estimated 0 -10-8-6-4-20 2 4 6 810 Applied voltage (V) 1 2 strain = d31V/t (d33=275pC/N , d31=-115pC/N ) 1 direct measurement 2 inferred from mechanical motion Sang-Gook Kim, MIT 43 Using computer microvision system.
Load more

Recommended publications
  • PHYSICS Glossary
    Glossary High School Level PHYSICS Glossary English/Haitian TRANSLATION OF PHYSICS TERMS BASED ON THE COURSEWORK FOR REGENTS EXAMINATIONS IN PHYSICS WORD-FOR-WORD GLOSSARIES ARE USED FOR INSTRUCTION AND TESTING ACCOMMODATIONS FOR ELL/LEP STUDENTS THE STATE EDUCATION DEPARTMENT / THE UNIVERSITY OF THE STATE OF NEW YORK, ALBANY, NY 12234 NYS Language RBERN | English - Haitian PHYSICS Glossary | 2016 1 This Glossary belongs to (Student’s Name) High School / Class / Year __________________________________________________________ __________________________________________________________ __________________________________________________________ NYS Language RBERN | English - Haitian PHYSICS Glossary | 2016 2 Physics Glossary High School Level English / Haitian English Haitian A A aberration aberasyon ability kapasite absence absans absolute scale echèl absoli absolute zero zewo absoli absorption absòpsyon absorption spectrum espèk absòpsyon accelerate akselere acceleration akselerasyon acceleration of gravity akselerasyon pezantè accentuate aksantye, mete aksan sou accompany akonpaye accomplish akonpli, reyalize accordance akòdans, konkòdans account jistifye, eksplike accumulate akimile accuracy egzatitid accurate egzat, presi, fidèl achieve akonpli, reyalize acoustics akoustik action aksyon activity aktivite actual reyèl, vre addition adisyon adhesive adezif adjacent adjasan advantage avantaj NYS Language RBERN | English - Haitian PHYSICS Glossary | 2016 3 English Haitian aerodynamics ayewodinamik air pollution polisyon lè air resistance
    [Show full text]
  • Piezoelectric Solutions: Piezo Components & Materials
    Piezoelectric Solutions Part I - Piezo Components & Materials Part II - Piezo Actuators & Transducers BAUELEMENTE, TECHNOLOGIE, ANSTEUERUNG Part III - Piezo Actuator Tutorial PIEZOWWW.PICERAMIC.DE TECHNOLOGY Contents Part I - Piezo Components & Materials .......... .3 Part II - Piezo Actuators & Transducers . .40 Part III - Piezo Actuator Tutorial ........ .73 Imprint PI Ceramic GmbH, Lindenstrasse, 07589 Lederhose, Germany Registration: HRB 203 .582, Jena local court VAT no .: DE 155932487 Executive board: Albrecht Otto, Dr . Peter Schittenhelm, Dr . Karl Spanner Phone +49 36604-882-0, Fax +49-36604-882-4109 info@piceramic .com, www .piceramic .com Although the information in this document has been compiled with the greatest care, errors cannot be ruled out completely . Therefore, we cannot guarantee for the information being complete, correct and up to date . Illustrati- ons may differ from the original and are not binding . PI reserves the right to supplement or change the information provided without prior notice . All contents, including texts, graphics, data etc ., as well as their layout, are subject to copyright and other protective laws . Any copying, modification or redistribution in whole or in parts is subject to a written permission of PI . The following company names and brands are registered trademarks of Physik Instrumente (PI) GmbH & Co . KG : PI®, PIC®, NanoCube®, PICMA®, PILine®, NEXLINE®, PiezoWalk®, NEXACT®, Picoactuator®, PIn- ano®, PIMag® . The following company names or brands are the registered trademarks of their
    [Show full text]
  • Piezoelectric Crystal Experiments for High School Science and En- Gineering Students
    Paper ID #14540 MAKER: Piezoelectric Crystal Experiments for High School Science and En- gineering Students Mr. William H. Heeter, Porter High School Engineering Dept. My name is William (Bill) Heeter. I graduated from Texas A&M with an Engineering degree in 1973. I worked in Industrial Distribution for over 30 years before becoming a high school pre-engineering teacher. I have been teaching engineering and technology for the past 13 years. I have been a Master Teacher for ”Project Lead the Way”, CTE co-Director, CTE Building Chair, Technology Teacher. My students have received many awards and college scholarships. One group of students received a provisional U.S. Patent. Several students have seen their work actually produced by industry, including the ordering touch screens used by Bucky’s. Dr. Sheng-Jen ”Tony” Hsieh, Texas A&M University Dr. Sheng-Jen (”Tony”) Hsieh is a Professor in the Dwight Look College of Engineering at Texas A&M University. He holds a joint appointment with the Department of Engineering Technology and the De- partment of Mechanical Engineering. His research interests include engineering education, cognitive task analysis, automation, robotics and control, intelligent manufacturing system design, and micro/nano manufacturing. He is also the Director of the Rockwell Automation laboratory at Texas A&M University, a state-of-the-art facility for education and research in the areas of automation, control, and automated system integration. Dr. Jun Zou, Department of Electrical and Computer Engineering, Texas A&M University Jun Zou received his Ph.D. degree in electrical engineering from the University of Illinois at Urbana- Champaign in 2002.
    [Show full text]
  • Piezoelectricity of Single-Atomic-Layer Mos2 for Energy Conversion and Piezotronics
    LETTER doi:10.1038/nature13792 Piezoelectricity of single-atomic-layer MoS2 for energy conversion and piezotronics Wenzhuo Wu1*, Lei Wang2*, Yilei Li3, Fan Zhang4, Long Lin1, Simiao Niu1, Daniel Chenet4, Xian Zhang4, Yufeng Hao4, Tony F. Heinz3, James Hone4 & Zhong Lin Wang1,5 The piezoelectric characteristics of nanowires, thin films and bulk The strain-induced polarization charges in single-layer MoS2 can also crystals have been closely studied for potential applications in sensors, modulate charge carrier transport at the MoS2–metal barrier and enable transducers, energy conversion and electronics1–3.Withtheirhighcrys- enhanced strain sensing. In addition, we have also observed large piezo- 4–6 tallinity and ability to withstand enormous strain , two-dimensional resistivity in even-layer MoS2 with a gauge factor of about 230 for the materials are of great interest as high-performance piezoelectric mate- bilayer material, which indicates a possible strain-induced change in band 18 rials. Monolayer MoS2 is predicted to be strongly piezoelectric, an structure . Our study demonstrates the potential of 2D nanomaterials effect that disappears in the bulk owing to the opposite orientations in powering nanodevices, adaptive bioprobes and tunable/stretchable of adjacent atomic layers7,8. Here we report the first experimental electronics/optoelectronics. study of the piezoelectric properties of two-dimensional MoS2 and In our experiments, MoS2 flakes were mechanically exfoliated onto show that cyclic stretching and releasing of thin MoS2 flakes with an a polymer stack consisting of water-soluble polyvinyl alcohol and poly odd number of atomic layers produces oscillating piezoelectric volt- (methyl methacrylate) on a Si substrate, with the total polymer thickness age and current outputs, whereas no output is observed for flakes with tuned to be 275 nm for good optical contrast.
    [Show full text]
  • Intrinsic Piezoelectricity in Two-Dimensional Materials † † Karel-Alexander N
    Letter pubs.acs.org/JPCL Intrinsic Piezoelectricity in Two-Dimensional Materials † † Karel-Alexander N. Duerloo, Mitchell T. Ong, and Evan J. Reed* Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States ABSTRACT: We discovered that many of the commonly studied two-dimensional monolayer transition metal dichalcogenide (TMDC) nanoscale materials are piezoelectric, unlike their bulk parent crystals. On the macroscopic scale, piezoelectricity is widely used to achieve robust electromechanical coupling in a rich variety of sensors and actuators. Remarkably, our density-functional theory calculations of the piezoelectric coefficients of monolayer BN, MoS2, MoSe2, MoTe2,WS2, WSe2, and WTe2 reveal that some of these materials exhibit stronger piezoelectric coupling than traditionally employed bulk wurtzite structures. We find that the piezoelectric coefficients span more than 1 order of magnitude, and exhibit monotonic periodic trends. The discovery of this property in many two- dimensional materials enables active sensing, actuating, and new electronic components for nanoscale devices based on the familiar piezoelectric effect. SECTION: Physical Processes in Nanomaterials and Nanostructures anoelectromechanical systems (NEMS) and nanoscale adsorption20 or introduction of specific in-plane defects,21 N electronics are the final frontier in the push for paving the way to a strong miniaturization and site-specific miniaturization that has been among the dominant themes of engineering of familiar piezoelectric technology using graphene. technological progress for over 50 years. Enabled by We now report that a family of widely studied atomically thin increasingly mature fabrication techniques, low-dimensional sheet materials are in fact intrinsically piezoelectric, elucidating materials including nanoparticles, nanotubes, and (near- an entirely new arsenal of “out of the box” active components )atomically thin sheets have emerged as the key components for NEMS and piezotronics.
    [Show full text]
  • IEEE-NMDC 2012 Conference Paper
    Proceedings of the 2012 IEEE Nanotechnology Material and Devices Conference October 16-19, 2012, Hawaii, USA Investigation of PVDF-TrFE Nanofibers for Energy Harvesting Sumon Dey, Mohsen Purahmad*, Suman Sinha Ray Alexander L. Yarin, Mitra Dutta, Fellow, IEEE *[email protected] Abstract- We have investigated the copolymer polyvinylidene energy harvesting, the generated pulse width is a critical fluoride, (PVDF-trifluoroethylene) for energy harvesting. parameter which should be considered during interface circuit Polyvinylidene fluoride (PVDF) nanofibers were electrospun on indium tin oxide (ITO) coated plastic. The electrical response of design and it can strongly affect the operation of interface nanofibers at different frequencies was investigated. The circuit and the net energy gain. experimental results demonstrate that the duty cycle of electrical The aim of this paper is to describe the effect of frequency response pulses is increased as the frequency of vibration is on the generated pulse widths from randomly oriented PVDF- increased. By using the fast Fourier transform (FFT) of the TrFE nanofibers. Experimental results demonstrate the change response pulses, the maximum power extracted has been calculated. of pulse widths on changing the frequency of the applied mechanical pressure. In addition, we also calculated maximum attainable power from PVDF-TrFE nanofibers. NTRODUCTION I. I A promising method of energy harvesting is the use II. PIEZOELECTRICITY EFFECT piezoelectric materials to capitalize on the ambient vibrations. Since the demand for high-performance wireless sensors is Piezoelectricity is the result of the rearrangement of increasing continuously, energy harvesting has been the focus electronic charges in materials with no inversion symmetry of much research for this application.
    [Show full text]
  • A Review on Mechanisms for Piezoelectric-Based Energy Harvesters
    energies Review A Review on Mechanisms for Piezoelectric-Based Energy Harvesters Hassan Elahi ∗,† ID , Marco Eugeni † and Paolo Gaudenzi † Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Via Eudossiana 18, 00184 Rome, Italy; [email protected] (M.E.); [email protected] (P.G.) * Correspondence: [email protected]; Tel.: +39-327-6544166 † These authors contributed equally to this work. Received: 23 May 2018; Accepted: 28 June 2018; Published: 14 July 2018 Abstract: From last few decades, piezoelectric materials have played a vital role as a mechanism of energy harvesting, as they have the tendency to absorb energy from the environment and transform it to electrical energy that can be used to drive electronic devices directly or indirectly. The power of electronic circuits has been cut down to nano or micro watts, which leads towards the development of self-designed piezoelectric transducers that can overcome power generation problems and can be self-powered. Moreover, piezoelectric energy harvesters (PEHs) can reduce the need for batteries, resulting in optimization of the weight of structures. These mechanisms are of great interest for many researchers, as piezoelectric transducers are capable of generating electric voltage in response to thermal, electrical, mechanical and electromagnetic input. In this review paper, Fluid Structure Interaction-based, human-based, and vibration-based energy harvesting mechanisms were studied. Moreover, qualitative and quantitative analysis of existing PEH mechanisms has been carried out. Keywords: piezoelectric; energy harvesting; vibrations; aeroelastic; smart material; fluid structure interaction; piezoelectricity; review 1. Introduction The phenomenon of energy harvesting based on piezoelectric transducers can be defined as the transformation of energy absorbed by a transducer from an operating environment to electric voltage that be used on the spot for actuation or stored in batteries for future usage [1–4].
    [Show full text]
  • Structure and Properties of Lead Zirconate Titanate Thin Films by Pulsed Laser Deposition GOH WEI CHUAN
    Structure and Properties of Lead Zirconate Titanate Thin Films by Pulsed Laser Deposition GOH WEI CHUAN (B.Sc (Hons), NUS) A THESIS SUBMITTED FOR THE DEGREE OF Doctoral of Philosophy Department of Physics National University of Singapore 2005 Acknowledgements I would like to express my deepest gratitude to my supervisors, Prof. Ong Chong Kim and Dr. Yao Kui. I would like to thank Prof. Ong for giving me the opportunity to study and perform research work in the Center of Superconducting and Magnetic Materials (CSMM). His passion and enthusiasm in the search for understanding the underlying physics of the experiments have deeply influenced my mindset in conducting experiments and will continue to be my source of inspiration and guidance. Without Prof. Ong’s constant guidance and criticism, I would have lost my bearing in the vast sea of knowledge, and would not have reached this far. I would also like to express my greatest appreciation to Dr. Yao Kui in Institute of Material Research and Engineering (IMRE). His constant advice and meticulous attention to the theoretical and experimental details had deeply influenced my way of research both in designing experiments and interpreting the results. Without his supervision and encouragements in countless hours of his time, it would not be possible for me to complete my publications and thesis. For that I am in debt to him and will forever remember his advice when pursuing my future endeavors. I am indebted to my fellow colleagues in CSMM, IMRE and Department of Physics, NUS, including A/P Sow Chorng Haur, Xu Sheng Yong, Wang Shi Jie, Li Jie, Yang Tao, Tan Chin Yaw, Rao Xue Song, Chen Lin Feng, Yan Lei, Kong Lin Bing, Liu Hua Jun, Lim Poh Chong, Yu Shu Hui, Gan Bee Keen and all those have shared their time helping me and discussing with me in this project.
    [Show full text]
  • THE PIEZOELECTRIC QUARTZ RESONATOR Kanr- S. Vaw Dvrn*
    THE PIEZOELECTRIC QUARTZ RESONATOR Kanr- S. Vaw Dvrn* CoNtsxrs Page 214 I. The Contributing Properties of Quartz . d1A A. Highly Perfect Elastic Properties. B. The Piezoelectric Property 216 C. ThePiezoelectricResonator. 2t6 D. Other Factors in the Common Circuit Use of Quartz 2r8 IL The Mdchanism of Circuit Influence by Quartz. 219 A. The Piezoelectric Strain-Current Relation 219 B. The Several Circuit Uses of a Crystal Resonator. ' '. 220 C. Crystal-Controlled Oscillators. 221 III. The Importance of Constant Frequencies in Communication ' ' ' " 223 A. Carrier Current Versus Simple Telephone Circuits. 223 ,14 B. The Carrier Principle in Radio Telephony . ' ' nnA C. Precision of Frequencies Essential. D. Tactical Benefits frorn Crystal Control . 225 IV. Thelmportanceof the Orientation of Quartz Radio Elements' " ' " " ' " ' 226 A. Orientation for Desired Mechanical Properties. ... 226 B. Predimensioning: Precise Duplication of Orientation and Dimensions' " ' ' 227 C. The Efiects of Orientation on Piezoelectric Properties. 228 D. The ObliqueCuts......... 229 V. The Ranges of the Characteristics in Quartz Crystal Units ' ' ' 229 A. Size of Crystal Plate or Bar.. ' 230 B. Frequency. 230 C. Type of Vibration. 230 232 D. "Cuts". .... E. Temperature Coeffcients of Frequenry. 234 F. Temperature Range. 235 G. Load Circuit. 235 H. Activity. 2s6 I. Voltage and Power Dissipation. 237 239 J. Finish, Surface, and Mounting of Quartz Resonators ' K. Holders. 240 VI. A Commenton the Future of PiezoelectricResonators' 241 VII. ListinEs of a Few Referencesin the GeneralField of This Paper' 243 L TnB CoNrnrnurrNc PRoPERTTESoF Quanrz A. Highly Perfect Elastic Properties The excellenceof quartz for use in frequency control is expressedin the large numerical values of Q in q\r.artzresonators, which the use of this * Director of Research, Long Branch Signal Laboratory, U' S' Army Signal Corps' Also, Professor of Physics, Wesleyan University, on leave of absence' 214 PIEZOELECTRTCIUARTZ RESONATOR 2tS highly elastic material makes possible.
    [Show full text]
  • High Performance Piezoelectric MEMS Microphones
    High Performance Piezoelectric MEMS Microphones by Robert John Littrell A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Mechanical Engineering) in The University of Michigan 2010 Doctoral Committee: Professor Karl Grosh, Chair Professor David R. Dowling Professor Khalil Najafi Assistant Professor Kenn Richard Oldham TABLE OF CONTENTS LIST OF FIGURES ............................... iv LIST OF TABLES ................................ vii LIST OF ABBREVIATIONS ......................... viii LIST OF SYMBOLS .............................. x CHAPTER I. Introduction .............................. 1 1.1 Capacitive and Piezoelectric MEMS Microphones . 1 1.2 Noise ............................... 3 1.3 Sensitivity ............................ 5 1.4 Linearity ............................. 8 1.5 Piezoelectric Materials . 9 1.6 Capacitive Microphone Embodiments . 11 1.7 Piezoelectric Microphone Embodiments . 12 1.8 GapsintheLiterature...................... 13 II. Modeling ................................ 15 2.1 Noise ............................... 16 2.1.1 Microphone Transducer Noise . 16 2.1.2 Microphone Circuitry Noise . 22 2.2 Sensitivity ............................ 25 2.2.1 Cantilever Transducer Sensitivity . 25 2.2.2 Diaphragm Transducer Sensitivity . 31 2.3 Linearity ............................. 35 2.3.1 THD of a Common Source Amplifier . 36 2.3.2 THDMeasurementResonator . 37 2.4 Combining Piezoelectric Elements . 38 2.5 Microphone Optimization . 41 ii 2.5.1 CantileverTransducer. 42 2.5.2
    [Show full text]
  • A New PZT (Lead Zirconate Titanate) Piezoelectric Transducer Performances Analysis
    International Journal of Research Studies in Science, Engineering and Technology Volume 1, Issue 6, September 2014, PP 1-7 ISSN 2349-4751 (Print) & ISSN 2349-476X (Online) A new PZT (Lead Zirconate Titanate) Piezoelectric Transducer Performances Analysis Pande A.S1, Prof (Dr.) Kushare B.E.2, Prof. A.K.Pathak3 1Electrical Engineering Dept. K. K. Wagh Institute of Engineering Education and Research, Nashik (MS), India. (Research Schola) 2Professor & H.O.D., Electrical Engineering Dept, K. K. Wagh Institute of Engineering Education and Research, Nashik (MS), India 3Electrical Engineering Dept. AVCOE, Sanagamner, Ahmednagar (MS), India Abstract: Presently there is number of Current measuring devices/ instrument are widely use for measurement of low and high current measurement. In the past decades there was surprisingly low attention of Electrical sensor, this sensor are very useful for replacing some kind of equipment in our existing power system. These measuring requirements are fulfill by using conventional sources out of which Piezoelectric Transducer is having major contribution in future. Considering the rate at which conventional sources are being consumed more power, cost, size and their life into control of power system, it is necessary to adopt alternate current measure ring technology for sustainable development. Out of various current measuring systems, Piezoelectric Transducer is most cost effective in addition to its various advantages. Considering the increasing share of Piezoelectric Transducer interfaced into the system it is necessary to study the power quality and current quality and stability issues. In case of conventional type CT use of copper is cost effective way is essential. This paper presents the operating principle, the performance MATLAB/SIMULATION, and the design of a piezoelectric transducer for measuring high currents.
    [Show full text]
  • Microphone Based on Polyvinylidene Fluoride (PVDF) Micro-Pillars and Patterned Electrodes
    Microphone based on Polyvinylidene Fluoride (PVDF) micro-pillars and patterned electrodes DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Jian Xu, B.E., M.E. Graduate Program in Mechanical Engineering The Ohio State University 2010 Dissertation Committee: Marcelo Dapino, Advisor Derek Hansford Ahmet Selamet Gregory Washington c Copyright by Jian Xu 2010 ABSTRACT Piezoelectric materials have the ability to transfer energy between the electric and mechanical domains. Polyvinylidene fluoride (PVDF) exhibits higher piezoelectricity than other polymer materials such as nylon and polyvinyl chloride. PVDF is a supe- rior material for sensors because its stress constant, the ability to convert stress into electrical energy, is more than 20 times higher than that of lead zirconate titanate. Nonetheless, there is significant interest in improving the effective stress constant of PVDF devices beyond the intrinsic sensitivity of the material. Significant research has focused on improvements in material properties, such as increasing β phase ratio or artificially introducing defects, and processing, such as optimizing stretch ratio and poling temperature or applying a high electric field. This research is focused on improving the stress constant, or sensor sensitivity, by means of design. The acoustic sensor presented in this dissertation exploits the key advantages of PVDF as a sensor material by means of two key design elements aimed at increasing the charge and decreasing the effective device capacitance. The first design element is a stress amplification mechanism through the area ratio between the overall surface exposed to acoustic waves and the area of an array of PVDF micro-pillars.
    [Show full text]