Piezoelectricity and ferroelectricity

Piezoelectricityand ferroelectricityApplications of piezoelectric materials

Prof.Mgr.Jiří Erhart, Ph.D.

Department of Physics FP TUL

FPM - Piezoelektřina 3 2

Piezoelectriceffect

Direct effect Converse effect

Sensorsstatic

Charge generators

ForceAcceleration

Pressure

Resonators

Ultrasound

US probesSonochemistry

RF devicesResonantsensors

Quartz watchQuartz

resonators

Gas, chemicaldetector

Actuators

Nonresonant

Bendingstructures

Resonant

US motors


Piezoelectric gas ignitors

Discharge between electrodes, charge is generated by piezoelectricity – hammer impact on PZT ceramic element

Piezo ceramics (inside)

HammerElectrodes


Quartz application

Force, pressure and acceleration sensors (e.g. Kistler, Switzerland)


Accelerometer

Deformation of piezoelectric element by the inertial force from the seismic mass


Quartz

SiO2 – natural or artificial crystal, quartz clock, e.g. wrist watch

W.P.Mason: US patent No. 2,081,405 (1937) – first patent on quartz clock resonator (fork resonator)

Quartz crystalWarren Perry Mason (1900-1986)


Quartz resonators

W.G.Cady – first frequency standard - US National Bureau of Standards, 1921

1926 – radio transmitter frequency stabilization

Walter Guyton Cady (1874 –1974)


Ultrasound motor

Ultrasound piezoelectric motors – transversal travelling wave

Shinsei motor

www.krazytech.com


Ultrasound motor

Ultrasound piezoelectric motor – elliptic motion of stator surface– friction with rotor

Example: diameter 30mm

www.pcbmotor.com


Ultrasound motor

Langevin transducer

PZT ceramics

stator

rotor

Paul Langevin (1872 -1946)


Ultrasound motor - PILine®

Elliptic motion of the tip joined with PZT ceramics element

www.pi.ws


Ultrasound atomization of liquids

Medicines application to mucous membrane in small dropletsAir humidificationAerosol deposition onto textile materials etc.

Droplet size is easilycontrollable by frequencyIt is in the range ofµmfor frequency 1-2 MHz


Ultrasound atomization of liquids

Liquid surface moves due to ultrasound wave

Average droplet size

Narrow distribution of droplet sizeProduction of atomized liquid amount is controllableDroplet size is controllable

FS

amFTFP

32

365.0rf

rρ

σ=


Liquid atomizers

• Ultrasound humidifiers

• Drug inhalers


Electronic cigarette

Atomiser inside cigaretteUS patent 20070267031 (2007)


Ultrasound generationand application

• Medical – diagnostics, healing

• Technology - welding, cleaning, NDT, sonochemistry, …


Piezoelectric transformer - Rosentype

US patent No.2,830,274 (1958), C.A.Rosen et al.

Piezoelectric transformer - Rosen type


Rosen type transformer

• Longitudinal plate vibration

• Common mechanical deformation

INOUT


Piezoelectric transformers – commercial products

Integrated with electronics – CCFL electronics

• Rosen-type (Fuji & Co., Japan)

• “Transoner” (Face Electronics, USA)

• Multilayer (Noliac A/S, Denmark)


Rosen type PT

Radial poling - nonhomogeneous

IN OUT

ceramics electrode polarization

OUT

IN

ceramics electrode polarization

rrr

UrE

1)ln(

)(12

=


Rosen type PT

Rectangular Rosen PT No. 2APC841 14mm/7mm/th.1mm

0

2

4

6

8

10

12

14

16

18

100 1000 10000 100000 1000000

Load [Ω]

Gai

n [-

]

0

10

20

30

40

50

60

70

80

Eff

icie

ncy

[%]

Gain Efficiency

Disc Rosen PT No. 1APC841 diam. 20mm/th.0.8mm

0

1

2

3

4

5

6

7

8

1000 10000 100000

Load [Ω]

Gai

n [-

]

0

2

4

6

8

10

12

14

16

Eff

icie

ncy

[%]

Gain Efficiency


Rosen type PT

Rectangular Rosen PT APC 841, l = 14mm, w = 7mm, b = 1mm,

V = 98mm3 No-load parameters ZL→∞, η→0

(((( )))) 2212 ====∞∞∞∞UU fr = 113.85 kHz

Optimum load parameter ZL = 10kΩ (((( )))) 312 ====OPTUU fr = 113.05 kHz

%77====OPTηηηη fr = 113.05 kHz

Peak power PIN = 56.5mW fr = 113.10 kHz POUT = 43.6mW fr = 113.08 kHz

Peak power density PIN/V = 0.58Wcm-3

POUT/V = 0.44Wcm-3 Input and Output impedance

ZIN = 167Ω fr = 112.9 kHz ZIN = 92.2kΩ fa = 115.4 kHz ZOUT = 1.68kΩ fr = 113.0 kHz ZOUT = 14.5MΩ fa = 123.4 kHz

Disc Rosen PT APC 841, r = 10mm, b = 0.8mm,

V = 251mm3 No-load parameters ZL→∞, η→0

(((( )))) 1912 ====∞∞∞∞UU fr = 120.25 kHz

Optimum load parameter ZL = 11kΩ (((( )))) 512 ====OPTUU fr = 119.60 kHz

%15====OPTηηηη fr = 119.60 kHz

Peak power PIN = 251.9mW fr = 119.63 kHz POUT = 37.6mW fr = 119.60 kHz

Peak power density PIN/V = 1.00Wcm-3

POUT/V = 0.15Wcm-3 Input and Output impedance

ZIN = 20.5Ω fr = 120.25 kHz ZIN = 342kΩ fa = 128.94 kHz ZOUT = 7.2kΩ fr = 120.21 kHz ZOUT = 54.0kΩ fa = 120.48 kHz


Power density for PT - comparison

Power density increased substantionally from the first PT’s application

K.Uchino: Piezoelectric motors and transformer, in Piezoelectricity, Springer Verlag 2008


Piezoelectric actuation

Direct piezoelectric effect – sensors

Converse piezoelectric effect – actuators, ultrasound generation

Sheard - mode

S5

15


Piezoelectric coefficients

Mechanical deformation is proportional to voltage

piezoelectriccoefficients d31, d33

Typical values d31≈100-300pC/N (10-12C/N=10-12m/V), d33≈ 200-600pC/N for PZT ceramics

x3

x1

x2

S3

S1

S2

T3

T2

T1

E3

tUE

EdS

EdS

EdS

/3

3333

3312

3311

====


Bending deformation, operation in static, quasistatic or dynamicmode for the actuator

Antiparallel (series) Parallel (electrical driving of one or both elements)

Piezoelectric ceramic bimorph

PZT

Metal

+

+


Bimorph parameters

• (Free) stroke

• Blocking force

• Resonance frequency

• Resonance deflection

voltage

stroke

force


Stroke, deflection

(Free) stroke (parallel bimorph)

Without metallic plate

( )( ) V

tshtthhs

Lthds

mE

mmm

mm

311

22311

23111

3642

6

++++

−=δ

Vh

Ld2

231

4

3=δ


Blocking force

Blocking force (parallel bimorph)

Without metallic plate

( )V

L

wth

s

dF m

Ebl

+−=

11

31

2

3

VL

hw

s

dF

Ebl11

31

2

3−=


Bimorph’s resonance

• Resonance frequency (with metallic plate)

• Deflection at the resonance (without metallic plate)

( ) ( )( )

8751.7,6941.4,8751.1

,2

,

)1(14

42131

3

1

4

2

321

11

11

2

32

112

2

=λ=λ=λρρ

===

+++++

ρπ+λ

=

P

mmm

E

EP

miri

Ch

tB

s

sA

BCB

ABB

sL

thf

( )32

2231

12

1,,

2

)cosh()cos(14

)sinh()sin(3

whIA

EIa

a

f

LLh

LLVd

=ρ

=π=Ω

ΩΩ+ΩΩΩ

=δ


Piezoelectric ceramic unimorph

Metallicmembrane

PZT ceramics

Agelectrode

Similar to bimorphin circular arrangement

Complicated mathematicalsolution


Unimorph’s parameters

(static) deflection- homogeneous unimorph

- heterogeneous unimorph )(2

28

3)( 22

21

231 ar

h

h

h

Vdr −

−=δ

)(4

3)( 22

231 ar

h

Vdr −=δ


Piezoelectric ceramic actuators

Bending elements (bimorph, unimorph, moonie, cymbal, THUNDER, Helimorph, RAINBOW)

Deflections up to 1-3mm, forces up to 0.1N!

Unimorph (membrane)

Bimorph

Electrode

PZT

Metallic plate


THUNDER®

TH in layer UNimorphDrivER and sensorSpecial high temperature – mechanical pre-stress

Deflections up to 8mm, force up to 100N!


HELIMORPH ®

Double spiral bimorph structure

High deflection up to 5mm, force up to 1N!

Drawback - brittleness


RAINBOW ®

Reduced And IN ternallyBiased Oxide Wafer

Monolithic ceramic structure

Internal gradient of chemical composition within plate thickness – piezoelectric coefficient gradient and very high permissible deformation up to 500%!


Moonie and cymbal

Moonie Cymbal

Composite structures – metallic cups and PZT plate are glued together; radial motion of ceramics is transformed to the axial motion of cups center

Deflection up to 50µm, small force; very high deflection sensitivity as a sensor of hydrostatic pressure


Operating parameters of bending actuators


Vibration of body inside the viscous liquid

Vibration of infinite plate– damped vibrations, penetration depthδ

Mechanical tension caused by viscous forces– phase shift

z

tjeuu ω−= 0

( )tzjz eeuv ωδδ −−= 0

ρωηδ 2=

)4

cos(0

πωωρητ +−= tu


Vibration of sphere in viscous liquid

Viscous drag force at harmonic vibration motion

Piezoelectric bimorph is used for the vibration generation and force sensing at the same time

ρωηδω 2

,0 ≡= − tjeuu

dt

duRRu

RRF

++

+=δω

ηρπδ

πη92

12

316 2


Bimorph

PZT plate

Metallic plate

Bimorphsubmergedinto water


Bimorph vibration submerged into liquid

Bimorph is approximated by the sphere inside liquid

Forced vibrations in liquid

Me, K, bin – effective mass, bimorph’s stiffness, internal damping

( ) ( )

+=

+=

=++++ −

R

Rb

RRM

eFKydt

dybb

dt

ydMM

i

tjinie

δδ

πηδρπ

ω

16

,29

132 2

3

02

2


Bimorph’s resonance

Mechanical resonance of bimorph is registered electrically by the bimorph, impedance spektrum

- Free in air – resonance frequency

- Damping inside liquid – resonance frequency

Width of resonance peak

e

ii M

Knf

π2=

ie

in

ie MM

bb

MM

K

++=

+=−= γωγωω ,,

21 2

022

02max

γ3


Princip le of the measurement by bimorph

• Calibration for the known liquid – radius estimate for the equivalent sphere

• Impedance spektrum of bimorph vibrating inside liquid→ γ, ωmax

• Viscosity and density calculation


Typical result

Second resonance of bimorphs inside liquid


Resonance parameters


Multilayer actuators

Many thin PZT layers in single segmentMultilayer segment are stacked together

with mechanical amplification by lever arms (Cedrat Technologies, France)

High blocking forces (kN), very small deflections (≈1-10µm) without mechanical amplification



Piezoelectric fuel injection module

Cedrat Technologies, Francie


Actuator parameters comparison

Low deflection – high blocking force

Craig D. Near, Piezoelectric Actuator Technology, Presented at SPIE Smart Structures and Materials

Conference, February 27, 1996


Deflection amplification for piezoelectric actuators

Deflection is not high enough for the most direct applications

Deflection amplification – lever mechanismor hydraulics

Piston

PiezostackHydraulicchamber

Piezostack

Lever


Piezoelectric valves

Ball valve Poppett valve

piezo-stack 2x THUNDER


Micropump

Dosage of small volumes of liquids – by piezoelectric bending elements

Bimorph as an active valve element


Operating mode forpiezoelectric element

(a) transversal or (b) longitudinal mode of piezoelectric element - membrane


Throttle valve

Throttle valve operated by ultrasonic piezoelectric motor - US patent No. 4,915,074

US motor


Pyroelectricity applications

• IR sensors for remote control

• Proximity sensor – door opening, guarding of space, parking sensor etc.

• Night vision – VIDICON camera

• Temperature distribution – IR camera


Recommended reading

J.Zelenka: Piezoelectric resonators, Elsevier, 1986A.H.Meitzler, H.M.O’Brian, H.F.Tiersten: Definition and measurement of radial mode coupling factors in

piezoelectric ceramic materials with large variations in Poisson’s ratio, IEEE Trans. Sonics Ultrason. SU-20, 3 (1973) 233-239

N.T.Adelman, Y.Stavsky, E.Segal: Radial vibrations of axially polarized piezoelectric ceramic cylinders, J.Acoust.Soc.Am. 57, 2 (1975) 356-360

A.Ballato, J.Ballato: Accurate electrical measurements of modern ferroelectrics, Ferroelectrics 182(1996) 29-59

IRE Standards on Piezoelectric Crystals: Determination of the Elastic, Piezoelectric, and Dielectric Constants—The Electromechanical Coupling Factor, Proceedings IRE (1958) 764–778

P.Hána, L.Burianová, D.Barošová, J.Zelenka, Ferroelectrics 224(1999) 39–46N.T.Adelman, Y.Stavsky: Flexural-extensional behavior of composite piezoelectric circular plates,

J.Acoust.Soc.Am. 67, 3 (1980) 819-822J.G.Smits, A.Ballato: Dynamic admittance matrix of piezoelectric cantilever bimorphs,

J.Microelectromechanical Systems 3, 3 (1994) 105-112J.G.Smits, S.I.Dalke, T.K.Cooney: The constituent equations of piezoelectric bimorphs, Sensors and

Actuators A 28 (1991) 41-61Q.M.Wang, L.E.Cross: Performance characteristics of piezoelectric cantilever bending actuators,

Ferroelectrics 215(1998) 187-213


Thank you for your attention!

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Piezoelectricity and ferroelectricity