Physik Instrumente PI CAT125E R3 Piezoelectric Ceramic Products

PI_CAT125E_R3_Piezoelectric_Ceramic_Products Fundamentals of Piezo Technology

User Manual: Physik Instrumente Catalogs, Brochures & Certificates

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PIEZO TECHNOLOGY

FUNDAMENTALS, CHARACTERISTICS AND APPLICATIONS

PIEZOCERAMIC

MATERIALS

COMPONENTS

INTEGRATION

Piezoelectric

Ceramic Products

FUNDAMENTALS, CHARACTERISTICS AND APPLICATIONS

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Contents

PI Ceramic – Leaders in Piezoelectric Technology .....................................3

Product Overview ...............................................................6

Fundamentals of Piezo Technology

Piezoelectric Effect and Piezo Technology ...........................................8

Electromechanics ...............................................................10

Dynamic Behavior ..............................................................12

Piezo Ceramics – Materials, Components, Products

Material Properties and Classification ..............................................14

Soft and Hard Piezo Ceramics ..................................................14

Lead-Free Materials ..........................................................15

Overview ...................................................................16

Material Data ..................................................................18

Temperature Dependence of the Coefficients .....................................20

Manufacturing Technology

Pressing Technology .........................................................22

Co-firing, Tape Technology, Multilayer ..........................................23

Flexibility in Shape and Design .................................................24

PICMA® Multilayer Actuators with Long Lifetime ..................................25

Metallization and Assembling Technology .......................................26

Piezo Ceramic Components: Dimensions ...........................................27

Testing Procedures .............................................................30

Integrated Components, Sub-Assemblies ...........................................31

Applications

Application Examples for Piezoceramic Elements ....................................32

Pumping and Dosing Techniques with Piezo Drives ................................33

Ultrasound Applications in Medical Engineering ..................................34

Ultrasonic Sensors ...........................................................35

Piezoelectric Actuators ........................................................37

Vibration Control ............................................................39

Adaptronics .................................................................40

Energy from Vibration – Energy Harvesting ......................................40

Ultrasonic Machining of Materials ..............................................41

Sonar Technology and Hydroacoustics .........................................41

PI Milestones ..................................................................42

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

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 owners: μManager,

LabVIEW, Leica, Linux, MATLAB, MetaMorph, Microsoft, National Instruments, Nikon, Olympus, Windows, Zeiss.

PIEZO TECHNOLOGY

Core Competences

of PI Ceramic

! Standard piezo com-

ponents for actuators,

ultrasonic and sensor

applications

! System solutions

! Manufacturing of piezo-

electric components of

up to several million

units per year

! Development of

custom-engineered

solutions

! High degree of flexibi-

lity in the engineering

process, short lead

times, manufacture of

individual units and

very small quantities

! All key technologies

and state-of-the-art

equipment for ceramic

production in-house

! Certified in accordance

with ISO 9001,

ISO 14001 and OHSAS

18001

PI Ceramic is one of the world’s market lead -

ers for piezoelectric actuators and sensors. PI

Ceramic provides everything related to piezo

ceramics, from the material and components

right through to the complete integration.

PI Ceramic provides system solutions for

research and industry in all high-tech mar-

kets including medical engineering, mechan-

ical engineer ing and automobile manufac-

ture, or semiconductor technology.

Materials Research and Development

PI Ceramic develops all its piezoceramic

materials itself. To this end PI Ceramic main-

tains its own laboratories, prototype manu-

facture as well as measurement and testing

stations. Moreover, PI Ceramic works with

leading universities and research institutions

at home and abroad in the field of piezoelec-

tricity.

Flexible Production

In addition to the broad spectrum of standard

products, the fastest possible realization of

customer-specific requirements is a top pri-

ority. Our pressing and multilayer technology

enables us to shape products with a short

lead time. We are able to manufacture indi-

vidual prototypes as well as high-volume

production runs. All processing steps are

undertaken in-house and are subject to con-

tinuous controls, a process which ensures

quality and adherence to deadlines.

Certified Quality

Since 1997, PI Ceramic has been certified

according to the ISO 9001 standard, where

the emphasis is not only on product quali-

ty but primarily on the expectations of the

customer and his satisfaction. PI Ceramic

is also certified according to the ISO 14001

(environmental management) and OHSAS

18001 (occupational safety) standards,

which taken together, form an Integrated

Management System (IMS). PI Ceramic is

a subsidiary of Physik Instrumente (PI) and

develops and produces all piezo actuators for

PI’s nanopositioning systems. The drives for

PILine® ultrasonic piezomotors and NEXLINE®

high-load stepping drives also originate from

PI Ceramic.

LEADERS IN PIEZOELECTRIC TECHNOLOGY

PI Ceramic

Company building of PI Ceramic in Lederhose, Thuringia, Germany.

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OUR MISSION

Reliability and Close Contact with our Customers

PI Ceramic provides

! Piezoceramic materials

(PZT)

! Piezoceramic

components

! Customized and appli-

cation-specific ultrasonic

transducers/transducers

! PICMA® monolithic

multilayer piezo actuators

Miniature piezo actuators

! PICMA® multilayer

bender actuators

! PICA high-load piezo

actuator

! PT Tube piezo actuators

! Preloaded actuators

with casing

! Piezocomposites –

DuraAct patch

transducers

Our aim is to maintain high, tested qual-

ity for both our standard products and for

custom-engineered components. We want

you, our customers, to be satisfied with the

performance of our products. At PI Ceramic,

customer service starts with an initial infor-

mative discussion and extends far beyond

the shipping of the products.

Advice from Piezo Specialists

You want to solve complex problems – we

won’t leave you to your own devices. We

use our years of experience in planning,

developing, designing and the production

of individual solutions to accompany you

from the initial idea to the finished product.

We take the time necessary for a detailed

understanding of the issues and work out

a comprehensive and optimum solution at

an early stage with either existing or new

technologies.

PI Ceramic supplies piezo-ceramic solutions

to all important high-tech markets:

! Industrial automation

! Semiconductor industry

! Medical engineering

! Mechanical and precision engineering

! Aviation and aerospace

! Automotive industry

! Telecommunications

After-Sales Service

Even after the sale has been completed,

our specialists are available to you and can

advise you on system upgrades or technical

issues. This is how we at PI Ceramic achieve

our objective: Long-lasting business rela-

tions and a trusting communication with

customers and suppliers, both of which

are more important than any short-term

success.

PIEZO TECHNOLOGY

STATE-OF-THE-ART MANUFACTURING TECHNOLOGY

Experience and Know-How

Developing and manufacturing piezoceram-

ic components are very complex processes.

PI Ceramic has many years of experience in

this field and has developed sophisticated

manufacturing methods. Its machines and

equipment are state of the art.

Rapid Prototyping

The requirements are realized quickly and

flexibly in close liaison with the customer.

Prototypes and small production runs of

custom-engineered piezo components are

available after very short processing times.

The manufacturing conditions, i.e. the

composition of the material or the sintering

temperature, for example, are individually

adjusted to the ceramic material in order to

achieve optimum material parameters.

Precision Machining Technology

PI Ceramic uses machining techniques from

the semiconductor industry to machine the

sensitive piezoceramic elements with a

particularly high degree of precision. Spe-

cial milling machines accurately shape the

components when they are still in the “green

state“, i.e. before they are sintered. Sintered

ceramic blocks are machined with precision

saws like the ones used to separate indi-

vi dual wafers. Very fine holes, structured

ceramic surfaces, even complex, three-

dimen sional contours can be produced.

Automated Series Production –

Advantage for OEM Customers

An industrial application often requires large

quantities of custom-engineered compo-

nents. At PI Ceramic, the transition to large

production runs can be achieved in a reliable

and low-cost way while maintaining the high

quality of the products. PI Ceramic has the ca-

pacity to produce and process medium-sized

and large production runs in linked automat-

ed lines. Automatic screen printers and the

latest PVD units are used to metallize the

ceramic parts.

Automated processes optimize throughput

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Piezoelectric Components

! Various different versions in many dif-

ferent geometries such as disks, plates,

tubes, customized shapes

! High resonant frequencies to 20 MHz

OEM Adaptations

! Piezo transducers for ultrasonic

applications

! Assembly of complete transducer

components

! 2D or line arrays

DuraAct Piezo Patch Transducers

! Actuator or sensor, structural health

monitoring

! Bendable and robust, preloaded due to

lamination

Control Electronics

! Different performance classes

! OEM modules and benchtop devices

IN-HOUSE DEVELOPMENT AND PRODUCTION

Product Overview

PIEZO TECHNOLOGY

PICMA® Multilayer Piezo Actuators

! Low piezo voltage to 120 V

! High stiffness

! Travel ranges to 100 µm

PICA High-Load Actuators

! Travel ranges to 300 µm

! Forces to 100 kN

PICMA® Multilayer Bending Actuators

! Bidirectional displacement to 2 mm

! Low operating voltage to 60 V

! Contractors, variable contours

Piezo Actuators with

Customized Equipment

! For use in a harsh environment

! Position and temperature monitoring

! For cryogenic temperatures

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Piezoelectric Effect and Piezo Technology

Piezoelectric materials convert electrical ener-

gy into mechanical energy and vice versa.

The piezoelectric effect is now used in many

everyday products such as lighters, loud-

speakers and signal transducers. Piezo actua-

tor technology has also gained acceptance

in automotive technology, because piezo-

controlled injection valves in combustion

engines reduce the transition times and signi-

ficantly improve the smoothness and exhaust

gas quality.

From the Physical Effect to Industrial Use

The word “piezo“ is derived from the Greek

word for pressure. In 1880 Jacques and Pier-

re Curie discovered that pressure generates

electrical charges in a number of crystals

such as Quartz and Tourmaline; they called

this phenomenon the “piezoelectric effect“.

Later they noticed that electrical fields can

deform piezoelectric materials. This effect is

called the “inverse piezoelectric effect“. The

industrial breakthrough came with piezo-

electric ceramics, when scientists discovered

that Barium Titanate assumes piezoelectric

characteristics on a useful scale when an

electric field is applied.

Piezoelectric Ceramics …

The piezoelectric effect of natural mono-

crystalline materials such as Quartz, Tour-

maline and Seignette salt is relatively small.

Polycrystalline ferroelectric ceramics such as

Barium Titanate (BaTiO3) and Lead Zirconate

Titanate (PZT) exhibit larger displacements

or induce larger electric voltages. PZT pie-

zo ceramic materials are available in many

modifications and are most widely used

for actuator or sensor applications. Special

dopings of the PZT ceramics with e.g. Ni, Bi,

Sb, Nb ions make it possible to specifically

optimize piezoelectric and dielectric parame-

ters.

… with Polycrystalline Structure

At temperatures below the Curie tempera-

ture, the lattice structure of the PZT crystal-

lites becomes deformed and asymmetric.

This brings about the formation of dipoles

and the rhombohedral and tetragonal cry-

stallite phases which are of interest for pie-

zo technology. The ceramic exhibits spon-

taneous polarization (see Fig. 1). Above the

Curie temperature the piezoceramic material

loses its piezoelectric properties.

Direct Piezoelectric Effect

Mechanical stresses arising as the result

of an external force that act on the piezo-

electric body induce displacements of the

electrical dipoles. This generates an elec-

tric field, which produces a corresponding

electric voltage. This direct piezoelectric

effect is also called the sensor or generator

effect.

Inverse Piezoelectric Effect

When an electric voltage is applied to an

unrestrained piezoceramic component it

brings about a geometric deformation. The

movement achieved is a function of the

polarity, of the voltage applied and the

direction of the polarization in the device.

The application of an AC voltage produ-

ces an oscillation, i.e. a periodic change of

the geometry, for example the increase or

reduction of the diameter of a disk. If the

body is clamped, i.e. free deformation is

constrained, a mechanical stress or force

is generated. This effect is frequently also

called the actuator or motor effect.

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

Fig. 1.

(1)

Unit cell with symmetrical,

cubic Perovskite structure,

T >

(2) Tetragonally distorted unit

cell, T<T

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

PIEZO TECHNOLOGY

Fig. 2. Electric dipoles in

domains:

(1) unpolarized,

ferroelectric ceramic,

(2) during and

(3) after the poling

(piezoelectric ceramic).

Ferroelectric Domain Structure

One effect of the spontaneous polarization

is that the discrete PZT crystallites become

piezoelectric. Groups of unit cells with the

same orientation are called ferroelectric

domains. Because of the random distribu-

tion of the domain orientations in the cera-

mic material no macroscopic piezoelectric

be havior is observable. Due to the ferro-

electric nature of the material, it is possible to

force permanent reorientation and alignment

of the differ ent domains using a strong elec-

tric field. This process is called poling (see

Fig. 2).

Polarization of the Piezoceramics

The poling process results in a remnant

polarization Pr which coincides with a

remnant expansion of the material and

which is degraded again when the mecha-

nical, thermal and electrical limit values of

the material are exceeded (see Fig. 3). The

ceramic now exhibits piezoelectric pro-

perties and will change dimensions when

an electric voltage is applied. Some PZT

ceramics must be poled at an elevated tem-

perature.

When the permissible operating tempe-

rature is exceeded, the polarized ceramic

depolarizes. The degree of depolarization is

depending on the Curie temperature of the

material.

An electric field of sufficient strength can

reverse the polarization direction (see Fig.

4). The link between mechanical and electri-

cal parameters is of crucial significance for

the widespread technical utilization of piezo

ceramics.

Fig. 3. The butterfly curve shows the typical

deformation of a ferroelectric “soft“ piezo ceramic

material when a bipolar voltage is applied.

The displacement of the ceramic here is based

exclusively on solid state effects, such as the ali-

gnment of the dipoles. The motion produced

is therefore frictionless and non-wearing.

Fig. 4. An opposing electric field will only

depolarize the material if it exceeds the

coercivity strength Ec. A further increase in the

opposing field leads to repolarization, but in

the opposite direction.

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

-Ec

-Pr

-Ps

-Ec

-Pr

-Ps

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FUNDAMENTAL EQUATIONS AND PIEZOELECTRIC COEFFICIENTS

Electromechanics

Polarized piezoelectric materials are charac-

terized by several coefficients and relation-

ships. In simplified form, the basic relation-

ships between the electrical and elastic

properties can be represented as follows :

D = d T + εTE

S = sET + d E

These relationships apply only to small elec -

trical and mechanical amplitudes, so-called

small signal values. Within this range the

relationships between the elastic deformati-

on (S) or stress (T) components and the com-

ponents of the electric field E or the electric

flux density D are linear.

Assignment of Axis

The directions are designated by 1, 2, and

3, corresponding to axes X, Y and Z of the

classical right-hand orthogonal axis set. The

rotational axes are designated with 4, 5 and 6

(see Fig. 5). The direction of polarization (axis

3) is established during the poling process

by a strong electrical field applied between

the two electrodes. Since the piezoelectric

material is anisotropic, the corresponding

physical quantities are described by tensors.

The piezoelectric coefficients are therefore

indexed accordingly.

Permittivity ε

The relative permittivity, or relative dielec-

tric coefficient, ε is the ratio of the absolute

permittivity of the ceramic material and the

permittivity in vacuum (ε

= 8.85 x 10-12 F/m),

where the absolute permittivity is a measu-

re of the polarizability. The dependency of

the permittivity from the orientation of the

electric field and the flux density is described

by indexes.

Examples

T permittivity value in the polarizati-

on direction when an electric field is

applied parallel to the direction of the

polarity (direction 3), under conditions

of constant mechanical stress (T = 0:

“

free

“

permittivity).

S permittivity if the electric field and

dielectric displacement are in direc-

tion 1 at constant deformation (S = 0:

“clamped“ permittivity).

Piezoelectric Charge or Strain Coefficient,

Piezo Modulus d

The piezo modulus is the ratio of induced

electric charge to mechanical stress or of

achievable mechanical strain to electric field

applied (T = constant).

Example

mechanical strain induced per unit of

electric field applied in V/m or charge

density in C/m2 per unit pressure in N/

m2, both in polarization direction.

Piezoelectric Voltage Coefficient gij

The piezoelectric voltage coefficient g is

the ratio of electric field E to the effective

mechanical stress T. Dividing the respec-

tive piezoelectric charge coefficient dij by

the corresponding permittivity gives the

corresponding gij coefficient.

Example

describes the electric field induced in

direction 3 per unit of mechanical stress

acting in direction 1. Stress = force per

unit area, not necessarily orthogonal.

D electric ﬂux density,

or dielectric

displacement

T mechanical stress

E electric ﬁeld

S mechanical strain

d piezoelectric charge

coefﬁcient

T dielectric permittivity

(for T = constant)

sE elastic coefﬁcient

(for E = constant)

Fig. 5. Orthogonal

coordinate system to

describe the properties

of a poled piezoelectric

ceramic. The polarization

vector is parallel to the

3 (Z)-axis.

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

PIEZO TECHNOLOGY

Elastic Compliance sij

The elastic compliance coefficient s is the

ratio of the relative deformation S to the

mechanical stress T. Mechanical and elec-

trical energy are mutually dependent, the

electrical boundary conditions such as

the electric flux density D and field E must

therefore be taken into consideration.

Examples

s33

E the ratio of the mechanical strain in

direction 3 to the mechanical stress

in the direction 3, at constant electric

ﬁeld (for E = 0: short circuit).

s55

D the ratio of a shear strain to the

effective shear stress at constant

dielectric displacement (for D = 0: open

electrodes).

The often used elasticity or Young’s mo-

dulus Yij corresponds in a ﬁrst approximati-

on to the reciprocal value of the correspon-

ding elasticity coefﬁcient.

Frequency Coefﬁcient Ni

The frequency coefficient N describes

the relationship between the geometrical

di mension A of a body and the corresponding

(series) resonance frequency. The indices

designate the corresponding direction of

oscillation N = fsA.

Examples

N3 describes the frequency coefficient

for the longitudinal oscillation of a

slim rod polarized in the longitudinal

direction.

N1 is the frequency coefﬁcient for the

transverse oscillation of a slim rod

polarized in the 3-direction.

is the frequency coefficient of the

thick ness

shear oscillation of a thin

disk.

NP is the frequency coefficient of the

planar oscillation of a round disk.

Nt is the frequency coefficient of the

thickness oscillation of a thin disk

polarized in the thickness direction.

Mechanical Quality Factor Qm

The mechanical quality factor Q

character-

izes the “sharpness of the resonance“ of

a piezoelectric body or resonator and is

primarily determined from the 3 dB band-

width of the series resonance of the system

which is able to oscillate (see Fig. 7 typical

impedance curve). The reciprocal value

of the mechanical quality factor is the

mechanical loss factor, the ratio of effecti-

ve resistance to reactance in the equivalent

circuit diagram of a piezoelectric resonator at

resonancem (Fig. 6).

Coupling Factors k

The coupling factor k is a measure of how

the magnitude of the piezoelectric effect is

(n o t an efficiency factor!). It describes the

ability of a piezoelectric material to convert

electrical energy into mechanical energy and

vice versa. The coupling factor is determi-

ned by the square root of the ratio of stored

mechanical energy to the total energy ab-

sorbed. At resonance, k is a function of the

corresponding form of oscillation of the

piezoelectric body.

Examples

k33 the coupling factor for the longitudinal

oscillation.

k31 the coupling factor for the transverse

oscillation.

kP the coupling factor for the planar radial

oscillation of a round disk.

kt the coupling factor for the thickness

oscillation of a plate.

k15 the coupling factor for the thickness

shear oscillation of a plate.

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The electromechanical behavior of a piezo-

electric element excited to oscillations can

be represented by an electrical equivalent

circuit diagram (s. Fig. 6). C0 is the capaci-

tance of the dielectric. The series circuit, con-

sisting of C1, L1, and R1, describes the change

in the mechanical properties, such as elastic

deformation, effective mass (inertia) and

mechanical losses resulting from internal

friction. This description of the oscillatory

circuit can only be used for frequencies

in the vicinity of the mechanical intrinsic

resonance.

Most piezoelectric material parameters are

determined by means of impedance mea-

surements on special test bodies according

to the European Standard EN 50324-2 at

resonance.

Fig. 7. Typical impedance curve

Fig. 6. Equivalent circuit diagram

of a piezoelectric resonator

Thin disk

Plate

Rod

Shear plate

Tube

radial

thickness

transverse

longitudinal

thickness shear

transversal

thickness

Shape Oscillations Electrically Mechanically

induced induced

Type Mechanical Series resonance displacement voltage

deformation frequency (small signal) (small signal)

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impedance Z

Frequency f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

ƒs =NP

ƒs =Nt

ƒs =N1

ƒs =N3

ƒs =N5

ƒs ≈Nt

ƒs ≈N1

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

TH U

OD >> TH

L >> W >> TH

3LL ≈ W >> TH

UL >> W >> TH

L >> OD >> TH

OSCILLATION MODES OF PIEZOCERAMIC ELEMENTS

Dynamic Behavior

PIEZO TECHNOLOGY

Figure 7 illustrates a typical impedance cur-

ve. The series and parallel resonances, fs and

fp, are used to determine the piezoelectric

parameters. These correspond to a good ap-

proximation to the impedance minimum fm

and maximum fn.

Oscillation States of Piezoelectric

Components

Oscillation states or modes and the de-

formation are decided by the geometry of the

element, mechano-elastic properties and

the orientations of the electric field and the

polarization. Coefficients see p. 10, speci-

fic values see p. 18. dimensions see p. 27.

The equations are used to calculate approx-

imation values.

Shape Oscillations Electrically Mechanically

induced induced

Type Mechanical Series resonance displacement voltage

deformation frequency (small signal) (small signal)

∆OD = U

d31OD

∆L = U

d31L

∆TH = d33U

∆L = U

d31L

∆TH = d33U

∆L = d33U

∆L = d15U

U = – F3

4g33TH

πOD2

U = – F3

g33L

W TH

U = – F3

g15 TH

L W

U = – F1

g31

WWW.PICERAMIC.COM

Material Properties and Classiﬁcation

PI Ceramic provides a wide selection of

piezoelectric ceramic materials based on

modified Lead Zirconate Titanate (PZT) and

Barium Titanate. The material properties

are classified according to the EN 50324

European Standard.

In addition to the standard types described

here in detail, a large number of modifica-

tions are available which have been adapted

to a variety of applications.

Internationally, the convention is to divide

piezo ceramics into two groups. The terms

“soft“ and “hard“ PZT ceramics refer to

the mobility of the dipoles or domains and

hence also to the polarization and depolar-

ization behavior.

“Soft“ Piezo Ceramics

Characteristic features are a comparably

high domain mobility and resulting “soft

ferroelectric“ behavior, i.e. it is relatively

easy to polarize. The advantages of the

“soft“ PZT materials are their large piezo-

electric charge coefficient, moderate per-

mittivities and high coupling factors.

Important fields of application for “soft“

piezo ceramics are actuators for micro-

positioning and nanopositioning, sensors

such as conventional vibration pickups,

ultrasonic transmitters and receivers for

flow or level measurement, for example,

object identification or monitoring as well

as electro-acoustic applications as sound

transducers and microphones, through

to their use as sound pickups on musical

instruments.

“Hard“ Piezo Ceramics

“Hard“ PZT materials can be subjected to

high electrical and mechanical stresses.

Their properties change only little under the-

se conditions and this makes them particu-

larly ideal for high-power applications. The

advantages of these PZT materials are the

moderate permittivity, large piezo electric

coupling factors, high qualities and very

good stability under high mechanical loads

and operating fields. Low dielectric losses

facilitate their continuous use in resonance

mode with only low intrinsic warming of

the component. These piezo elements

are used in ultrasonic cleaning (typically

kHz frequency range), for example, the

machining of materials (ultrasonic welding,

bonding, drilling, etc.), for ultra sonic pro-

cessors (e.g. to disperse liquid media), in

the medical field (ultrasonic tartar removal,

surgical instruments etc.) and also in sonar

technology.

PIEZO TECHNOLOGY

Piezoelectric ceramics, which nowadays

are based mainly on Lead Zirconate-Lead

Titanate compounds, are subject to an ex-

emption from the EU directive to reduce

hazardous substances (RoHS) and can there-

fore be used without hesitation. PI Ceramic is

nevertheless aiming to provide high-per for-

mance lead-free piezoceramic materials and

thus provide materials with a guaranteed

future. PI Ceramic is currently inves tigating

technologies to reliably manufacture

lead-free ceramic components in series

pro duc tion.

First Steps Towards Industrial Use

with PIC700

The PIC700 material, which is currently in

laboratory production, is the ﬁrst lead-free

piezo ceramic material being offered on

the market by PI Ceramic. PIC700 is based

on Bismuth Sodium Titanate (BNT) and

has very similar characteristics to Barium

Titanate materials. PIC700 is suitable for

ultrasonic transducers in the MHz range as

well as sonar and hydrophone applications.

Characteristics of the Lead-Free

Piezo Ceramic Material

The maximum operating temperature of

the BNT-based ceramic is around 200 °C.

The permittivity and piezoelectric coupling

factors of BNT components are lower than

those of conventional, PZT materials. Even

though PIC700 is suitable for a number of

applications, an across-the-board replace-

ment for PZT piezoelectric elements in

technical applications is not in sight at the

moment.

Lead-Free Materials

Lead-Free and with High Linearity

Piezoceramic actuators exhibit nonlinear

displacement behavior: The voltage applied

is thus not a repeatable measure for the

position reached. Sensors must therefore

be used in applications where the position

is relevant. The crystalline PIC050 material,

in contrast, has a linearity which is signi-

ficantly improved by a factor of 10 so that a

position sensor is not necessary.

PIC050 is used for actuators and nanoposi-

tioning systems with the tradename Picoac-

tuator®. They have the high stiffness and

dynamics of actuators made of PZT material

but their displacement is limited: Travel of

up to +/-3 μm results with a maximum pro-

file of 20 mm.

Picoactuator® in Nanopositioning

In precision positioning technology, Physik

Instrumente (PI) uses these actuators precis-

ly where this small displacement with high

dynamics and accuracy is required. The

high linearity means that they can operate

without position control which otherwi-

se sets an upper limit for the dynamics of

the system as a result of the limited control

bandwidth.

Since it is used in positioning systems

the PIC050 material is only supplied as a

translational or shear actuator in predeﬁ-

ned shapes. The standard dimensions are

similar to those of the PICA shear actuators

(see www.piceramic.com).

Crystalline Piezo Material for Actuators

The PIC050 crystal forms translucent layers in the Picoactuator®.

High-dynamics nanopositioning

system with Picoactuator®

technology.

Typical dimensions of cur-

rent PIC 700 components

are diameters of 10 mm and

thicknesses of 0.5 mm.

WWW.PICERAMIC.COM

Material Properties and Classification

Material

designation

General description of the material properties

“Soft“-PZT

Classification in accor-

dance with EN 50324-1

ML-Standard

DOD-STD-1376A

PIC151 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: High permittivity, large coupling factor,

high piezoelectric charge coefficient

Suitable for: Actuators, low-power ultrasonic transducers,

low-frequency sound transducers. Standard material for

actuators of the PICA series: PICA Stack, PICA Thru

600 II

PIC255 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Very high Curie temperature, high permittivity,

high coupling factor, high charge coefficient, low mechanical

quality factor, low temperature coefficient

Suitable for: Actuator applications for dynamic operating

conditions and high ambient temperatures (PICA Power series),

low-power ultrasonic transducers, non-resonant broadband

systems, force and acoustic pickups, DuraAct patch transducers,

PICA Shear shear actuators

200 II

PIC155 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Very high Curie temperature, low mechanical

quality factor, low permittivity, high sensitivity (g coefficients)

Suitable for: Applications which require a high g coefficient

(piezoelectric voltage coefficient), e.g. for microphones and

vibration pickups with preamplifier, vibration measurements

at low frequencies

200 II

PIC153 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: extremely high values for permittivity, coupling

factor, high charge coefficient, Curie temperature around 185 °C

Suitable for: Hydrophones, transducers in medical diagnostics,

actuators

600 VI

PIC152 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Very high Curie temperature

Suitable for: Use at temperatures up to 250 °C

(briefly up to 300 °C).

200 II

PIEZO TECHNOLOGY

Material

designation

General description of the material properties

“Hard“-PZT

Classification in accor-

dance with EN 50324-1

ML-Standard

DOD-STD-1376A

PIC181 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Extremely high mechanical quality factor,

good temperature and time constancy of the dielectric and

elastic values

Suitable for: High-power acoustic applications, applications in

resonance mode

100 I

PIC184 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Large electromechanical coupling factor, moderate-

ly high quality factor, excellent mechanical and electrical stability

Suitable for: High-power ultrasound applications, hydroacoustics,

sonar technology

100 I

PIC144 Material: Modified lead zirconate titanate

Characteristics: Large electromechanical coupling factor, high

quality factor, excellent mechanical and electrical stability, high

compressive resistance

Suitable for: High-power ultrasound applications, hydroacoustics,

sonar technology

100 I

PIC241 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: High mechanical quality factor, higher permittivity

than PIC181

Suitable for: High-power acoustic applications, piezomotor drives

100 I

PIC300 Material: Modified Lead Zirconate-Lead Titanate

Characteristics: Very high Curie temperature

Suitable for: Use at temperatures up to 250 °C

(briefly up to 300 °C).

100 I

Lead-Free Materials

PIC050 Material: Spezial crystalline material

Characteristics: Excellent stability, Curie temperature >500 °C

Suitable for: High-precision, hysteresis-free positioning in

open-loop operation, Picoactuator®

PIC700 Material: Modified Bismuth Sodium Titanate

Characteristics: Maximum operation temperature 200 °C,

low density, high coupling factor of the thickness mode

of vibration, low planar coupling factor

Suitable for: Ultrasonic transducers > 1MHz

WWW.PICERAMIC.COM

Soft PZT materials Hard PZT materials Lead-free

materials

Unit PIC151

PIC255/

PIC2521)

PIC155

PIC153

PIC152

PIC181

PIC1842)

PIC1442)

PIC241

PIC300

PIC110

PIC7002)

Physical and dielectric properties

Density ρg/cm37.80 7.80 7.80 7.60 7.70 7.80 7.75 7.95 7.80 7.80 5.50 5.6

Curie temperature Tc°C 250 350 345 185 340 330 295 320 270 370 150 2003)

Relative permittivity in the polarization direction

to polarity

ε33

Τ/ε0

ε11

Τ/ε0

2400

1980

1750

1650

1450

1400

4200 1350 1200

1500

1015

1250

1500

1650

1550

1050

950

950 700

Dielectric loss factor tan δ10-3 20 20 20 30 15 3 5 4 5 3 15 30

Electromechanical properties

Coupling factor kp

k31

k33

k15

0.62

0.53

0.38

0.69

0.62

0.47

0.35

0.69

0.66

0.62

0.48

0.35

0.69

0.62 0.48

0.58

0.56

0.46

0.32

0.66

0.63

0.55

0.44

0.30

0.62

0.65

0.60

0.48

0.30

0.66

0.50

0.46

0.32

0.64

0.63

0.48

0.43

0.25

0.46

0.32

0.30

0.42

0.18

0.15

0.40

Piezoelectric charge coefficient d31

d33

d15

10-12 C/N

-210

500

-180

400

550

-165

360

600

300

-120

265

475

-100

219

418

-110

265

-130

290

265

-80

155

-50

120

Piezoelectric voltage coefficient g31

g33

10-3 Vm/N

-11.5

-11.3

-12.9

-11.2

-11.1

24.4

-10.1

-9.8

-9.5

-11.9

Acousto-mechanical properties

Frequency coefficients Np

Hz·m

1950

1500

1750

1950

2000

1420

2000

1960

1500

1780

1990

1960

2250

1920

2270

1640

2010

2110

2195

1590

1930

2035

2180

1590

2020

2190

1590

1550

2140

2350

1700

2100

3150

2300

2500

Elastic compliance coefficient S11

S33

E10-12 m2/ N

15.0

19.0

16.1

20.7

15.6

19.7

11.8

14.2

12.7

14.0

12.4

15.5

12.6

14.3

11.1

11.8

Elastic stiffness coefficient C33

D1010 N/m210.0 11.1 16.6 14.8 15.2 13.8 16.4

Mechanical quality factor Qm100 80 80 50 100 2000 400 1000 400 1400 250

Temperature stability

Temperature coefficient of εΤ

(in the range -20 °C to +125 °C)

TK ε33

10-3 / K

Time stability (relative change of the parameter per decade of time in %)

Relative permittivity

Coupling factor

Cε

-1.0

-2.0

-4.0

-2.0

-5.0

-8.0

SPECIFIC PARAMETERS OF THE STANDARD MATERIALS

Material Data

PIEZO TECHNOLOGY

Recommended operating temperature:

50 % of Curie temperature.

1) Material for the Multilayer tape

technology.

2) Preliminary data, subject to change

3) Maximum operating temperature

The following values are valid approxima-

tions for all PZT materials from

PI Ceramic:

Speciﬁc heat capacity:

WK = approx. 350 J kg-1 K-1

Speciﬁc thermal conductivity :

WL = approx. 1.1 W m-1 K-1

Poisson‘s ratio (lateral contraction):

σ = approx. 0.34

Coefﬁcient of thermal expansion:

α3 = approx. -4 to -6 × 10-6 K-1

(in the polarization direction, shorted)

α1 = approx. 4 to 8 × 10-6 K-1

(perpendicular to the polarization direction,

shorted)

Static compressive strength:

> 600 MPa

The data was determined using test

pieces with the geometric dimensions laid

down in EN 50324-2 standard and are typical

values.

All data provided was determined 24 h to

48 h after the time of polarization at an am-

bient temperature of 23 ±2 °C.

A complete coefﬁcient matrix of the individ-

ual materials is available on request. If you

have any questions about the interpretation

of the material characteristics please contact

PI Ceramic (info@piceramic.com).

Soft PZT materials Hard PZT materials Lead-free

materials

Unit PIC151 PIC255/

PIC2521)

PIC155 PIC153 PIC152 PIC181 PIC1842) PIC1442) PIC241 PIC300 PIC110 PIC7002)

Physical and dielectric properties

Density ρg/cm37.80 7.80 7.80 7.60 7.70 7.80 7.75 7.95 7.80 7.80 5.50 5.6

Curie temperature Tc°C 250 350 345 185 340 330 295 320 270 370 150 2003)

Relative permittivity in the polarization direction

to polarity

ε33

Τ/ε0

ε11

Τ/ε0

2400

1980

1750

1650

1450

1400

4200 1350 1200

1500

1015

1250

1500

1650

1550

1050

950

950 700

Dielectric loss factor tan δ10-3 20 20 20 30 15 3 5 4 5 3 15 30

Electromechanical properties

Coupling factor kp

k31

k33

k15

0.62

0.53

0.38

0.69

0.62

0.47

0.35

0.69

0.66

0.62

0.48

0.35

0.69

0.62 0.48

0.58

0.56

0.46

0.32

0.66

0.63

0.55

0.44

0.30

0.62

0.65

0.60

0.48

0.30

0.66

0.50

0.46

0.32

0.64

0.63

0.48

0.43

0.25

0.46

0.32

0.30

0.42

0.18

0.15

0.40

Piezoelectric charge coefficient d31

d33

d15

10-12 C/N

-210

500

-180

400

550

-165

360 600 300

-120

265

475

-100

219

418

-110

265

-130

290

265

-80

155

-50

120 120

Piezoelectric voltage coefficient g31

g33

10-3 Vm/N

-11.5

-11.3

-12.9

27 16 25

-11.2

-11.1

24.4

-10.1

-9.8

-9.5

16 -11.9

Acousto-mechanical properties

Frequency coefficients Np

Hz·m

1950

1500

1750

1950

2000

1420

2000

1960

1500

1780

1990

1960

2250

1920

2270

1640

2010

2110

2195

1590

1930

2035

2180

1590

2020

2190

1590

1550

2140

2350

1700

2100

3150

2300

2500

Elastic compliance coefficient S11

S33

E10-12 m2/ N

15.0

19.0

16.1

20.7

15.6

19.7

11.8

14.2

12.7

14.0

12.4

15.5

12.6

14.3

11.1

11.8

Elastic stiffness coefficient C33

D1010 N/m210.0 11.1 16.6 14.8 15.2 13.8 16.4

Mechanical quality factor Qm100 80 80 50 100 2000 400 1000 400 1400 250

Temperature stability

Temperature coefficient of εΤ

(in the range -20 °C to +125 °C) TK ε33 10-3 / K 6465 2 3 5 2

Time stability (relative change of the parameter per decade of time in %)

Relative permittivity

Coupling factor

Cε

-1.0

-2.0

-4.0

-2.0

-5.0

-8.0

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Temperature Dependence of the Coefﬁcients

∆ C/C (%) ∆ C/C (%)

∆ k31 / k31 (%)





∆ fs/ fs (%)

Temperature curve of the

capacitance C

 Materials: PIC151,

PIC255 and PIC155

 Materials: PIC181,

PIC241 and PIC300

Temperature curve of the

resonant frequency of the

transverse oscillation fs

 Materials: PIC151,

PIC255 and PIC155

 Materials: PIC181,

PIC241 and PIC300

Temperature curve of the

coupling factor of the

transverse oscillation k31

 Materials: PIC151,

PIC255 and PIC155

 Materials: PIC181,

PIC241 and PIC300



∆ fs/ fs (%)





∆ k31 / k31 (%)

PIEZO TECHNOLOGY

∆ d31 / d31 (%)



∆ d31 / d31 (%)

∆ L/L (%)

Thermal strain in the polarization direction Thermal strain perpendicular to the polarization

direction ∆ L/L (%)

1. Heating

Cooling

2. Heating

1. Heating

Cooling

2. Heating

1. Heating

Cooling

2. Heating

1. Heating

Cooling

2. Heating



Speciﬁc Characteristics

Thermal properties using the example of

the PZT ceramic PIC255

! The thermal strain exhibits different

behavior in the polarization direction and

perpendicular to it.

! The preferred orientation of the domains

in a polarized PZT body leads to an

anisotropy. This is the cause of the varying

thermal expansion behavior.

! Non-polarized piezoceramic elements are

isotropic. The coefficient of expansion is

approximately linear with a TK of approx

2 · 10-6 / K.

! The effect of successive temperature

changes must be heeded particularly in

the application. Large changes in the cur-

ve can occur particularly in the first tem-

perature cycle.

! Depending on the material, it is possib-

le that the curves deviate strongly from

those illustrated.

Temperature curve of

the piezoelectric charge

coefficient d31

 Materials: PIC151,

PIC255 and PIC155

 Materials: PIC181,

PIC241 and PIC300

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Piezo Components Made by Pressing

Technology

Piezoceramic bulk elements are manufac-

tured from spray-dried granular material

by mechanical hydraulic presses. The com-

pacts are either manufactured true to size,

taking into account the sintering contraction,

or with machining excesses which are then

reworked to achieve the required precision.

The sintered ceramic material is hard and

can be sawn and machined, if required.

Screen printing is used to metallize the pie-

zo elements and sputtering processes (PVD)

are employed for thin metallizing layers. The

sintered elements are then polarized.

Stack Design for Actuators

Piezo actuators are constructed by stacking

several piezoceramic bulk elements and

intermediate metal foils. Afterwards an ou-

ter insulation layer made of polymer mate-

rial is applied.

Final inspection

Manufacture of Piezo Components

Using Pressing Technology

Assembling and joining technology for

actuators, sound transducers, transducers

Polarization

Application of electrodes: Screen

printing, PVD processes, e.g. sputtering

Lapping, grinding, surface grinding,

diamond cutting

Thermal processing

Sintering at up to 1300 °C

Pressing and shaping

Granulation, spray drying

Milling

Pre-sintering (calcination)

Mixing and grinding

of the raw materials

Piezoceramic disks

with center hole

EFFICIENT PROCESSES FOR SMALL, MEDIUM-SIZED AND LARGE PRODUCTION RUNS

Manufacturing Technology

PIEZO TECHNOLOGY

Film Technology for Thin Ceramics

Components

Thin ceramic layers are produced by tape

casting. This process can achieve minimal

individual component thicknesses of only

50 μm.

The electrodes are then applied with special

screen printing or PVD processes.

Multilayer Piezo Actuators: PICMA®

Multilayer co-firing technology is an espe -

cially innovative manufacturing process.

The first step is to cast tapes of piezocera-

mic materials which are then provided with

electrodes while still in the green state. The

component is then laminated from individ-

ual layers. In the following electrodes and

ceramic are sintered together in a single

processing step.

The patented PICMA® design comprises an

additional ceramic insulation layer which

protects the inner electrodes from environ-

mental effects. Any further coatings made of

polymer material, for example, are therefore

not required. This means that PICMA® piezo

actuators remain stable even when subject

to high dynamic load. They achieve a higher

reliability and a lifetime which is ten times

longer than conventional multilayer piezo

actuators with a polymer insulation.

After the mechanical post-processing is com-

plete, the multilayer actuators are provided

with contact electrodes and are polarized.

PICMA® actuators with patented,

meander-shaped external electrodes

for up to 20 A charging current

Co-firing Process / Multilayer Technology / Piezo

Components inCeramics Tape Technology

Final inspection

Polarization

Application of contact electrodes,

termination

Grinding

Thermal processing

Binder burn out and sintering

at up to 1100 °C

Isostatic pressing

Laminating

Application of electrodes

by screen printing

Tape casting

Slurry preparation

Fine grinding of the raw materials

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Shaping of Compacts

Components such as disks or plates can be

manufactured at low cost with a minimum

thickness from as low as 0.2 mm. Inboard

automatic cutoff saws produce such pieces in

large numbers.

Modern CNC technology means the sintered

ceramic elements can be machined with the

highest precision. Holes with diameters of

down to 0.3 mm can be produced. Almost

any contours can be shaped with accuracies

to one tenth of a millimeter. Surfaces can be

structured and the components can be milled

to give a three-dimensional fit.

Ultrasonic machining processes are used

to manufacture thin-walled tubes with wall

thicknesses of 0.5 mm.

Robot-Assisted Series Production

Automated assembly and production lines

use fast pick-and-place devices and comput-

er-controlled soldering processes, for ex-

ample. An annual production run of several

million piezoelectric components and more

is thus no problem.

All Possible Shapes Even with

Full-Ceramic Encapsulation

PI Ceramic can manufacture almost any

shape of PICMA® multilayer piezo actua-

tor using the latest production technology.

Hereby, all surfaces are encapsulated with

ceramic insulation.

We can manufacture not only various ba-

sic shapes, e.g. round or triangular cross-

sections, but also insulated center holes on

benders, chips or stack actuators, making it

easier to integrate them.

Special milling machines work the sensitive

ceramic ﬁlms in the green state, i.e. befo-

re sintering. The individual layers are then

equipped with electrodes and laminated.

The co-ﬁring process is used to sinter the

ceramic and the internal electrodes together,

the same process as with PICMA® standard

actuators.

Flexibility in Shape and Design

Centerless, cylindrical grinding of piezoceramic rods

PIEZO TECHNOLOGY

The internal electrodes and the ceramic of

PICMA® multilayer actuators are sintered

together (co-ﬁring technology) to create a

monolithic piezoceramic block. This pro-

cess creates an encapsulating ceramic lay-

er which provides protection from humi-

dity and from failure caused by increased

leakage current. PICMA® actuators are there-

fore far superior to conventional, polymer-

insulated multilayer piezo actuators in terms

of reliability and lifetime. The monolithic

ceramic design also gives rise to a high

resonance frequency, making the actuators

ideal for high-dynamic operation.

Large Temperature Range – Optimum

UHV Compatibility – Minimal Outgassing

– Neutral in Magnetic Fields

The particularly high Curie temperature

of 320 °C gives PICMA® actuators a usa-

ble temperature range of up to 150 °C, far

beyond the 80 °C limit of conventional mul-

tilayer actuators. This and the exclusive use

of inorganic materials provide the optimum

conditions for use in ultra-high vacuums: No

outgassing and high bake-out temperatures.

PICMA® piezo actuators even operate in the

cryogenic temperature range, albeit at re -

duced travel. Every actuator is constructed

exclusively of non-ferromagnetic materials,

giving them extremely low residual magne-

tism of the order of a few nanotesla.

Low Operating Voltage

In contrast to most commercially available

multilayer piezo actuators, PICMA® actu-

ators achieve their nominal displacement

at operating voltages far below 150 V. This

characteristic is achieved by using a parti c-

ularly ﬁne-grained ceramic material which

means the internal layers can be thin.

The PICMA® actuators are at least partially

protected by the following patents:

German Patent No. 10021919

German Patent No. 10234787

German Patent No. 10348836

German Patent No. 102005015405

German Patent No. 102007011652

US Patent No. 7,449,077

PICMA® Multilayer Actuators with Long Lifetime

Automatic soldering machine with PICMA® actuators

WWW.PICERAMIC.COM

Thick-Film Electrodes

Screen printing is a standard procedure to ap-

ply the metal electrodes to the piezoce-ram ic

elements. Typical film thicknesses here are

around 10 μm. Various silver pastes are used

in this process. After screen print ing these

pastes are baked on at tempera-tures above

800 °C.

Thin-Film Electrodes

Thin-film electrodes are applied to the

ceramic using modern PVD processes

(sputtering). The typical thickness of the

metallization is in the range of 1 μm. Shear

elements must be metallized in the polar-

ized state and are generally equipped with

thin-film electrodes.

PI Ceramic has high-throughput sputtering

facilities which can apply electrodes made of

metal alloys, preferably CuNi alloys and no-

ble metals such as gold and silver.

Soldering Methods

Ready-made piezo components with

connecting wires are manufactured by

specially trained staff using hand solder-

ing processes. We have the latest automatic

soldering machines at our disposal to solder

on miniaturized components and for larger

production runs. Soldered joints which must

be extremely reliable undergo special visu-

al inspections. The optical techniques used

for this purpose range from the stereomi-

cro-scope through to camera inspection sys-

tems.

Mounting and Assembling Technology

The joining of products, e. g. with adhesives,

is carried out in the batch production using au-

tomated equipment which executes the nec-

essary temperature-time-regime (e.g. curing

of epoxy adhesives) and hence guarantees

uniform quality. The choice of adhesive and

the curing regime are optimized for every

product, taking into consideration the mate-

rial properties and the intended operational

conditions. Specifically devel-oped dosing

and positioning systems are used for com-

plex special designs. The piezoceramic stack

actuators of the PICA series, high-voltage

bender-type actuators and ultrasonic trans-

ducers are constructed in jointing processes

and have proved successful many times over

in the semi-conductor industry and in medical

engineering thanks to their high reliability.

Fully loaded sputtering equipment

THE COMPLETE PROCESS IS IN-HOUSE

Metallization and Assembling Technology

PIEZO TECHNOLOGY

! P indicates the

poling direction.

! The dimensions are

mutually dependent

and cannot be

chosen arbitrarily.

! The minimum

dimensions are

determined by

physical and

technological limits.

The thickness or

wall thickness, for

example, is limited

by the mechanical

strength of the

ceramic during

machining.

! Maximum thickness

for polarization:

30 mm

Labeling of the polarity

The surface of the

electrode which is at

the positive potential

during polarization is

marked with a dot or

a cross. Alternatively

and particularly for

thin-film electrodes

the direction of

polarization is marked

by coloring the

electrode material:

A reddish color

indicates the electrode

which was at the

positive potential

during the polarization.

Standard tolerances

Dimensions, as fired

± 0.3 mm resp. ± 3 %

Length L, width W (dimensions; tolerance)

< 15 mm; ± 0.15 mm < 40 mm; ± 0.25 mm

< 20 mm; ± 0.20 mm < 80 mm; ± 0.30 mm

Outer diameter OD,

inner diameter ID

(dimensions; tolerance)

< 15 mm; ± 0.15 mm < 40 mm; ± 0.25 mm

< 20 mm; ± 0.20 mm < 80 mm; ± 0.30 mm

Thickness TH (dimensions; tolerance)

< 10 mm; ± 0.05 mm < 40 mm; ± 0.15 mm

< 20 mm; ± 0.10 mm < 80 mm; ± 0.20 mm

Disk / Outer diameter OD: 2 to 80 mm

rod / cylinder Thickness TH: 0.15 to 30 mm

Plate / block Length L: 1 to 80 mm,

Width W: 1 to 60 mm,

Thickness TH: 0.1 to 30 mm

Shear plate Length L: max. 75 mm,

Width W: max. 25 mm,

Thickness TH: 0.2 to 10 mm

Tube Outer diameter OD: 2 to 80 mm,

Inner diameter ID: 0.8 to 74 mm,

Length L: max. 30 mm

Ring Outer diameter OD: 2 to 80 mm,

Inner diameter ID: 0.8 to 74 mm,

Thickness TH: max. 70 mm

Bender elements Length L: 3 to 50 mm,

constructed in Width W: 1 to 25 mm,

series / parallel Thickness TH: 0.4 to 1.5 mm

Round bender elements on request.

Preferred dimensions:

Diameter: 5 to 50 mm,

Thickness: 0.3 to 2 mm

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

Dimension Tolerance

Deviation from flatness < 0.02 mm

(slight bending of

thin disks or plates

is not taken

into account)

Deviation < 0.02 mm

from

parallelism

Deviation <_ 0.4 mm

from

concentricity

Frequency ± 5 % (< 2 MHz)

tolerance ± 10 % (>

= 2 MHz)

Tolerance of ± 20 %

electric capacitance

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

DIMENSIONS

Piezoceramic Components

WWW.PICERAMIC.COM

Components with standard dimensions can

be supplied at very short notice on the basis

of semi-finished materials in stock. Extreme

values cannot be combined. Geometries

which exceed the standard dimensions are

available on request.

 Disk / rod / cylinder  Disk / rod

with defined resonant frequency

 Plate / block

 Electrodes: Fired silver

(thick film) or PVD

(thin film, different

materials: e. g. CuNi or

Au)

 Points: Resonant

frequency > 1 MHz

Circles: Resonant

frequency < 1 MHz

Electrodes: Fired silver

(thick film) or PVD

(thin film, different

materials: e. g. CuNi or

Au)

 Electrodes: Fired silver

(thick film) or CuNi or Au

(thin film)

Standard Dimensions

TH OD in mm

in mm

3 5 10 16 20 25 35 40 45 50

0.20 •••••

0.25 •••••

0.30 ••••••

0.40 •••••••

0.50 •••••••••

0.75 ••••••••••

1.00 ••••••••••

2.00 ••••••••••

3.00

••••••••••

4.00

••••••••••

5.00

••••••••••

10.00

••••••••••

20.00

••••••••••

TH OD in mm

in MHz

3 5 10 16 20 25 35 40 45 50

.00 •••••

5.00 ••••••

4.00 •••••••

3.00 ••••••••

2.00 ••••••••

1.00 ••••••••

0.75 oooooooo

0.50 ooooooo

0.40

oooooo

0.25

oooo

0.20

ooo

TH LxW in mm

in mm

4 x 4 5 x 5 10 x 10 15 x 15 20 x 20 25 x 20 25 x 25 50 x 30 50 x 50 75 x 25

0.20 •••••

0.25 •••••

0.30 •••••••

0.40 •••••••

0.50 •••••••••

0.75 ••••••••••

1.00 ••••••••••

2.00 ••••••••••

3.00

••••••••••

4.00

••••••••••

5.00

••••••••••

10.00

••••••••••

20.00

••••••••

PIEZO TECHNOLOGY

Rings

* Tolerances as fired,

s. table p. 27

Design

Tubes

Design

Tubes with special electrodes

Design

Quartered outer

electrodes

Soldering instructions

for users

All our metallizations

can be soldered in

conformance with

RoHS. We recom-

mend the use of a

solder with the com-

position Sn 95.5. Ag

3.8. Cu 0.7. If the

piezoceramic element

is heated throughout

above the Curie

temperature, the

material is depolari-

zed, and there is thus

a loss of, or reduction

in, the piezoelectric

parameters.

This can be prevented

by adhering to the

following conditions

under all circum-

stances when solde-

ring:

! All soldered

contacts must be

point contacts.

! The soldering times

must be as short

as possible (≤ 3 sec).

! The speciﬁc

soldering

temperature must

not be exceeded.

 Disk / rod

with defined resonant frequency

Wrap-around

contacts

OD in mm TH in mm Electrodes:

10 / 16 / 20 / 20 / 25 / 40 0.5 / 1.0 / 2.0 Fired silver

(thick ﬁlm)

or PVD (thin ﬁlm)

OD in mm ID in mm TH in mm Electrodes:

10 2.7 0.5/1.0/2.0 Fired silver

10* 4.3* 0.5/1.0/2.0 (thick film)

10* 5* 0.5/1.0/2.0 or CuNi

12.7 5.2* 0.5/1.0/2.0 (thin film)

25 16* 0.5/1.0/2.0

38 13* 5.0/6.0

50 19.7* 5.0/6.0/9.5

OD in mm ID in mm L in mm Electrodes:

76 60 50 Inside:

40 38 40 Fired silver

20 18 30 (thick ﬁlm)

10 9 30 Outside:

10 8 30 Fired silver

6.35 5.35 30 (thick ﬁlm)

3.2 2.2 30 or CuNi or Au

2.2 1.0 20 (thin ﬁlm)

OD in mm ID in mm L in mm Electrodes:

20 18 30 Inside:

10 9 30 Fired silver

10 8 30 (thick ﬁlm)

6.35 5.53 30 Outside:

3.2 2.2 30 Fired silver

2.2 1.0 30 (thick ﬁlm)

or CuNi or Au

(thin ﬁlm)

Disks with special electrodes (wrap-around contacts)

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

∆L

Polarisation

axis

Impendanz Z

Frequenz f

fmfn

∆ L

(2)

–

(3)

–

(1)

–

P C/m2

E kV/cm

-Ec

-Pr

-Ps

–

1(r)

3(r)

Radialschwingung

Dickenschwingung

Radialschwingung

Dickenschwingung

Längsschwingung

Radialschwingung

Dickenschwingung

TH P

(1)

(2)

Ti, Zr

Längsschwingung

Dickenschwingung

1(r)

TH TH

(Z)

2(Y)

(X)1

(Z)

2(Y)

(X)1

WTH

WWW.PICERAMIC.COM

Comprehensive quality management con-

trols all production process at PI Ceramic,

from the quality of the raw materials through

to the finished product. This ensures that

only released parts that meet the quality

speci fications go on for further processing

and delivery.

Electrical Testing

Small-Signal Measurements

The data for the piezoelectric and dielectric

properties such as frequencies, impedanc-

es, coupling factors, capacitances and loss

factors is determined in small-signal mea -

s urements.

Large-Signal Measurements

DC measurements with voltages of up

to 1200 V are carried out on actuators to de-

termine the strain, hysteresis and dielectric

strength in an automated routine test.

Geometric and Visual Testing Processes

For complex measurements, image pro-

cessing measurement devices and white-

light interferometers for topographical

exami nations are available.

Visual Limit Values

Ceramic components must conform to

certain visual specifications. PI Ceramic has

set its own criteria for the quality assess-

ment of the surface finishes, which follow

the former MIL-STD-1376. A large variety

of appli cations are taken into account, for

special requirements there are graduated

sorting categories. Visual peculiarities must

not negatively affect the functioning of the

component.

The finish criteria relate to:

! surface finish of the electrode

! pores in the ceramic

! chipping of the edges, scratches, etc.

Quality Level

All tests are carried out in accordance with

the DIN ISO 2859 standardized sampling

method. The AQL 1.0 level of testing ap-

plies for the electrical assessment, for ex-

ample. A special product specification can

be agreed for custom-engineered products.

This includes the relevant release records,

plots of the measured values or individual

measured values of certain test samples

through to the testing of each individual

piece, for example.

Measurement of Material Data

The data is determined using test pieces

with the geometric dimensions laid down

in accordance with the EN 50324-2 stan-

dard and are typical values (see p. 14 ff).

Con- formance to these typical parameters

is documented by continual testing of the

individual material batches before they are

released. The characteristics of the individ-

ual product can deviate from this and are

determined as a function of the geometry,

varia-tions in the manufacturing processes

and measuring or control conditions.

STANDARDIZED PROCEDURES PROVIDE CERTAINTY

Testing Procedures

PIEZO TECHNOLOGY

Ceramics in Different Levels of Integration

PI Ceramic integrates piezo ceramics into

the customer’s product. This includes both

the electrical contacting of the elements ac-

cording to customer requirements and the

mounting of components provided by the

customer, i. e. the gluing or the casting of

the piezoceramic elements. For the custom-

er, this means an accelerated manu facturing

process and shorter lead times.

Sensor Components – Transducers

PI Ceramic supplies complete sound trans-

ducers in large batches for a wide variety

of application fields. These include OEM as-

semblies for ultrasonic flow measurement

technology, level, force and acceleration

measurement.

Piezo Actuators

The simplest form for a piezo actuator is

a piezo disk or plate, from which stack

actuators with correspondingly higher

displacement can be constructed. As an

alternative, multilayer actuators are man-

ufactured in different lengths from piezo

films with layer thicknesses below 100 μm.

Shear actuators consist of stacks of shear

plates and are polarized such that they have

a displacement perpendicular to the field

applied. Bender actuators in different ba-

sic forms are constructed with two layers

(bimorph) by means of multilayer techno-

logy and thus provide a symmetric displace-

ment.

Piezo actuators can be equipped with

sensors to measure the displacement and

are then suitable for repeatable position-

ing with nanometer accuracy. Piezo actua-

tors are often integrated into a mechanical

system where lever amplification increases

the travel. Flexure guiding systems then

provide high stiffness and minimize the

lateral offset.

Piezo Motors

Piezo ceramics are the drive element for

piezomotors from Physik Instrumente (PI),

which make it possible to use the special

characteristics of the piezo actuators over

longer travel ranges as well.

PILine® piezo ultrasonic motors allow for

very dynamic placement motions and can

be manufactured with such a compact form

that they are already being used in many

new applications.

Piezo stepping drives provide the high

forces which piezo actuators generate over

several millimeters. The patented NEXLINE®

and NEXACT® drives from PI with their

complex construction from longitudinal,

shear and bender elements and the nec-

essary contacting are manufactured com-

pletely at PI Ceramic.

FROM THE CERAMIC TO THE COMPLETE SOLUTION

Integrated Components, Sub-Assemblies

WWW.PICERAMIC.COM

Medical engineering, biotechnology, me-

chanical engineering or production techno-

logy through to semiconductor technology

– countless fields benefit from the piezo-

electric characteristics of the components.

Both the direct and the inverse piezoelectric

effect have industrial applications.

Direct Piezoelectric Effect

The piezo element converts mechanical

quantities such as pressure, strain or accel-

eration into a measureable electric voltage.

Mechano-Electrical Transducers

! Sensors for acceleration and pressure

! Vibration pickups, e.g. for the detection of

imbalances on rotating machine parts or

crash detectors in the automotive field

! Ignition elements

! Piezo keyboards

! Generators, e. g. self-supporting energy

sources (energy harvesting)

! Passive damping

Acousto-Electrical Transducers

! Sound and ultrasound receivers,

e.g. microphones, level and flow

rate measurements

! Noise analysis

! Acoustic Emission Spectroscopy

Inverse Piezoelectric Effect

The piezo element deforms when an electric

voltage is applied; mechanical motions or

oscillations are generated.

Electro-Mechanical Transducers

Actuators, such as translators, bender ele-

ments, piezo motors, for example:

! Micro- and nanopositioning.

! Laser Tuning

! Vibration damping

! Micropumps

! Pneumatic valves

Electro-Acoustic Transducers

! Signal generator (buzzer)

! High-voltage sources / transformers

! Delay lines

! High-powered ultrasonic generators:

Cleaning, welding, atomization, etc.

Ultrasonic signal processing uses both

effects and evaluates propagation times,

reflection and phase shift of ultrasonic wa-

ves in a frequency band from a few hertz

right up to several megahertz.

Applications are e. g.

! Level measurement

! Flow rate measurement

! Object recognition and monitoring

! Medical diagnostics

! High-resolution materials testing

! Sonar and echo sounders

! Adaptive structures

VERSATILE AND FLEXIBLE

Application Examples for Piezo Ceramic Products

PIEZO TECHNOLOGY

Increasing miniaturization places conti-

nuously higher demands on the components

used, and thus on the drives for microdosing

systems as well. Piezoelectric elements pro-

vide the solution here: They are reliable, fast

and precise in operation and can be shaped

to fit into the smallest installation space. At

the same time their energy consumption is

low, and they are small and low-cost. The

dosing quantities range from milliliter, mi-

croliter, nanoliter right down to the picoliter

range.

The fields of application for piezoelectric

pumps are in laboratory technology and

med ical engineering, biotechnology, chemi-

cal analysis and process engineering which

frequently require reliable dosing of minute

amounts of liquids and gases.

Micro-Diaphragm Pumps,

Microdosing Valves

The drive for the pump consists of a pie-

zo-electric actuator connected to a pump

diaphragm, usually made of metal or sili-

con. The deformation of the piezo element

changes the volume in the pump chamber,

the drive being separated from the medium

to be pumped by the diaphragm. Depen-

ding on the drop size and the diaphragm lift

thus required, and also the viscosity of the

medium, they can be driven directly with pie-

zo disks, piezo stack actuators or by means

of levered systems.

Their compact dimensions also make the-

se dosing devices suitable for lab-on-a-chip

applications.

Piezo drives are also used for opening and

closing valves. The range here is from a

simple piezo element or bender actuator for

a diaphragm valve, preloaded piezo stack ac-

tuators for large dynamics and force through

to piezo levers which carry out fine dosing

even at high backpressure.

In the automotive industry, fuel injection

systems driven by multilayer stack actuators

are also microdosing valves.

Peristaltic Pumps, Jet Dispensers

So-called peristaltic pumps are ideal in

cases where liquids or gases are to be

dosed accurately and also as evenly and

with as little pulsing as possible. The

external mechanical deformation of the

tube forces the medium to be transported

through this tube. The pumping direction is

determined by the control of the individual

actuators.

The drive element consists of flat piezo bend -

er elements, compact piezo chip actuators

or piezo stack actuators, depending on the

power and size requirements. Bender ac-

tuators are suitable mainly for applications

with low backpressure, e.g. for liquids with

low viscosity.

Piezo actuators are better able to cope with

higher backpressure and are suitable for

dosing substances with higher viscosity, but

require more space.

Piezoelectric Microdispensers,

Drop-on-Demand

Piezoelectric microdispensers consist of a

liquid-filled capillary which is shaped into

a nozzle and a surrounding piezo tube.

When a voltage is applied, the piezo tube

contracts and generates a pressure wave

in the capillary. This means that individual

drops are pinched off and accelerated to a

velocity of a few meters per second so that

they can travel over several centimeters.

The volume of the drop varies with the

properties of the medium transported, the

dimensions of the pump capillaries and the

control parameters of the piezo actuator.

Micro-channels etched into silicon can also

be used as nozzles.

Pumping and Dosing Techniques with Piezo Drives

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The piezoelectric effect is used for a lar-

ge number of applications in the life sci-

ences: For example, for imaging in medical

diagnostics, in therapy for the treatment of

pain, for aerosol generation or the remo-

val of tartar from teeth, for scalpels in eye

surgery, for monitoring liquids, such as in

the detection of air bubbles in dialysis, or

also as a drive for dispensers and micro-

pumps.

If high power densities are required, as is

the case with ultrasonic tartar removal or for

surgical instruments, for example, “hard“

PZT materials are used.

Ultrasonic Instruments in Surgical and

Cosmetic Applications

Nowadays, instruments with ultrasonic

drives allow minimally invasive surgical

techniques in eye and oral surgery, for ex-

ample. Devices for liposuction are also of-

ten based on ultrasonic technology. Piezo

elements have long been used as ultrasonic

generators to remove mineral deposits on

human teeth.

The principle is always similar and works

just like ultrasonic material machining:

Piezoceramic composite systems made of

ring disks clamped together are integrated

in a sonotrode in the form of a medical in-

strument. This transmits vibration amplitu-

des in the μm range at operating frequen-

cies of around 40 kHz.

Ultrasound Imaging – Sonography

The big advantage of sonography is the

harmlessness of the sound waves, which is

why the method is widely used. The ultra-

sonic transmitter contains a piezo element,

which generates ultrasonic waves and also

detects them again. The ultrasonic trans-

mitter emits short, directional sound wave

pulses which are reflected and scattered by

the tissue layers to different degrees. By

measuring the propagation time and the

magnitude of the reflection an image of the

structure under investigation is produced.

Ultrasound Applications in Medical Engineering

Instruments for the removal of tartar with ultrasound,

OEM product. The piezo disks can be clearly seen.

PIEZO TECHNOLOGY

Ultrasound Therapy

This method involves irradiating the tissue

with ultrasonic waves by means of an ultra-

sonic transmitter. On the one hand, mechan-

ical, longitudinal waves generate vibrations

in the tissue, on the other, they convert part

of the ultrasonic energy into heat.

Typical working frequencies are in the ran-

ge 0.8 to over 3 MHz, both continuous wave

and pulsed wave ultrasonic techniques

being used in the application. The vibrati-

on amplitudes transmitted are in the range

around 1 μm.

Different effects are achieved depending

on the energy of the radiation. High-energy

shock waves are used to destroy kidney

stones, for example. Low-energy shock wa-

ves effect a type of micro-massage, and are

used for the treatment of bones and tissue

and in physiotherapy among other things.

In cosmetic applications ultrasonophoresis,

i.e. the introduction of drugs into the skin, is

becoming increasingly important.

Aerosol Production

Ultrasound makes it possible to nebulize

liquids without increasing the pressure or

the temperature, a fact which is of crucial

importance particularly for sensitive sub-

stances such medicines.

The process is similar to high-frequency

ultrasonic cleaning – a piezoceramic disk

fixed in the liquid container and oscillating

in resonance generates high-intensity ultra-

sonic waves. The drops of liquid are created

near the surface by capillary waves.

The diameter of the aerosol droplets is

determined by the frequency of the ultra-

sonic waves: The higher the frequency, the

smaller the droplets.

For direct atomization, where the piezo

element oscillating at high frequency is in

direct contact with the liquid, the piezo sur-

face is specially treated against aggressive

substances.

Flow Rate Measurement

In many areas the measurement of flow

rates is the basis for processes operating

in a controlled way. In modern building

services, for example, the consumption

of water, hot water or heating energy is

recorded and the supply as well as the

billing is thus controlled.

In industrial automation and especially in

the chemical industry, volume measurement

can replace the weighing of substance

quantities.

Not only the flow velocity, but also the

concentration of certain substances can be

detected.

The measurement of the propagation time

is based on the transmitting and receiving

of ultrasonic pulses on alternating sides

in the direction of flow and in the opposi-

te direction. Here, two piezo transducers

operating as both transmitter and receiver

are arranged in a sound section diagonally

to the direction of flow.

The Doppler effect is used to evaluate the

phase and frequency shift of the ultraso-

nic waves which are scattered or reflected

by particles of liquid. The frequency shift

between the emitted wave front and the

reflected wave front received by the same

piezo transducer is a measure of the flow

velocity.

Ultrasonic Sensors:

Piezo Elements in Metrology

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Level Measurement

For propagation time measurements the

piezo transducer operates outside the

medium to be measured as both transmit-

ter and receiver. It emits an ultrasonic pulse

in air which is reflected by the content. The

propagation time required is a measure of

the distance travelled in the empty part of

the container.

This allows non-contact measurements

whereby the level of liquids, and also solids,

in silos for example, can be measured.

The resolution or accuracy depends on how

well the ultrasonic pulse is reflected by the

respective surface.

Submersible transducers, or tuning fork

sensors, are almost exclusively used as lev-

el switches; several of these sensors at dif-

ferent heights are required to measure the

level. The piezo transducer excites a tuning

fork at its natural frequency. When in con-

tact with the medium to be measured, the

resonance frequency shifts and this is eval-

uated electronically. This method works re-

liably and suffers hardly any breakdowns.

Moreover, it is independent of the type of

material to be filled.

Detection of Particles and Air Bubbles

The ultrasonic bubble sensor provides a

reliable control of liquid transport in tubes.

The sensor undertakes non-contact detec-

tion of the air and gas bubbles in the liq-

uid through the tube wall, and thus allows

continuous quality monitoring.

The application possibilities are in the

medical, pharmaceutical and food technol-

ogy fields. The sensors are used to mon-

itor dialysis machines, infusion pumps or

transfusions. Industrial applications include

control technology, such as the monitoring

of dosing and filling machines, for example.

Acceleration and Force Sensors,

Force Transducer

The key component of the piezoelectric

acceleration sensor is a disk of piezoelec-

tric ceramic which is connected to a seismic

mass. If the complete system is accelerated,

this mass increases the mechanical defor-

mation of the piezo disk, and thus increases

the measurable voltage. The sensors detect

accelerations in a broad range of frequencies

and dynamics with an almost linear char-

acteristic over the complete measurement

range.

Piezoelectric force sensors are suitable

for the measurement of dynamic tensile,

compression and shearing forces. They can

be designed with very high stiffness and can

also measure high-dynamic forces. A very

high resolution is typical.

Ultrasonic Sensors:

Piezo Elements in Metrology

Example of a tuning fork for level measurement,

OEM product

PIEZO TECHNOLOGY

Piezoelectric translators are ceramic solid

state actuators which convert electrical en-

ergy directly into linear motion with theo-

retically unlimited resolution. The length

of the actuator changes by up to 0.15 % in

this process. The actuators simultaneously

generate large static and dynamic forces.

Their special characteristics mean that piezo

actuators are ideal for semiconductor, opti-

cal and telecommunications applications.

They are also used in the automotive ﬁeld,

in pneumatic valve technology and vibration

damping, and for micropumps.

PI Ceramic provides not only hundreds

of standard versions but also special cus-

tom-ized versions quickly and reliably. The

actuators can be equipped with position

sensors for applications requiring high

closed-loop linearity of motion.

Piezo Systems with

High Force Generation: PICA

So-called high-voltage piezo actuators are

manufactured from piezoceramic disks in

a stack construction. The individual layers

are produced by pressing technology. Ap-

plica-tions for the high-load actuators can

be found in mechanical engineering for out-

of-round rotations, for example, in active vi-

bration control or for switching applications.

Many modifications are possible:

! Customized materials

! Layer thickness and thus voltage range

! Dimensions and basic form

! Force ranges resp. custom load

! Design and material of end pieces

! Extra-tight length tolerances

! Integrated piezoelectric sensor disks

! Special high / low temperature versions

! Vacuum-compatible and non-magnetic

versions

Piezoelectric Actuators

Piezo Actuators from

PI Ceramic

! Motion with sub-

nanometer resolution

! High forces (up to

over 50,000 N), high

load capacity (up to

100 MPa)

! Microsecond

response

! Free of play and fric-

tion

! Minimum power

consumption when

maintaining its

position

! Non-wearing

! High reliability

(> 109 switching

cycles)

! Suitable for vacuum

use and cleanrooms

! Can operate at

cryogenic

temperatures

! Magnetic ﬁelds have

no inﬂuence and

are themselves not

inﬂuenced

Choice of piezo stack actuators

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Reliable Piezo Actuators with

Low Operating Voltage: PICMA®

PICMA® multilayer actuators are construct-

ed using tape technology and are subse-

quently sintered in the multilayer co-firing

process. The special PICMA® PZT ceramic

and its manufacturing technique produce an

ideal combination of stiffness, capacitance,

displacement, temperature stability and

lifetime. The typical operating voltage of the

PICMA® multilayer actuators is 100 to 120 V.

PICMA® piezo actuators are the only mul-

tilayer actuators in the world with ceramic

encapsulation. This technology protects the

PICMA® actuators from environmental influ-

ences, in particular humidity, and ensures

their extremely high reliability and perfor-

mance even under harsh industrial oper-

ating conditions. The lifetime of PICMA®

actuators is significantly better than that of

piezo actuators with conventional polymer

encapsulation.

Since PICMA® piezo actuators do not re-

quire additional polymer insulation and can

be operated up to 150 °C they are ideal for

use in high vacuum. They even work, at a

reduced travel, in the cryogenic temperature

range.

Many fields of application benefit from

this reliability: Precision engineering and

precision machining as well as switches

and pneumatic or hydraulic valves. Further

applications can be found in the fields of ac-

tive vibration control, nanotechnology, me-

trology, optics and interferometry.

Preloaded Actuators – Levers –

Nanopositioning

PICMA® piezo actuators from PI Ceramic

are the key component for nanoposition-

ing systems from Physik Instrumente (PI).

They are supplied in different levels of in-

tegration: As simple actuators with position

sensor as an optional extra, encased with

or without preload, with lever amplifica-

tion for increased travel, right through to

high-performance nanopositioning systems

where piezo actuators drive up to six axes by

means of zero-wear and frictionless flexure

guidings.

What they all have in common is a motion

resolution in the nanometer range, long

lifetimes and outstanding reliability. The

combination of PICMA® actuators, flex-

ure guiding and precision measurement

systems produces nanopositioning devices

in the highest performance class.

The fields of application range from

semiconductor technology, metrology,

microscopy, photonics through to bio-

technology, aerospace, astronomy and cryo-

genic environments.

Piezo nanopositioning system

with parallel kinematics and

displacement sensors

Piezoelectric PICMA® actuators

Lever amplified system

Piezoelectric Actuators

PIEZO TECHNOLOGY

If a mechanical system is knocked off

balance, this can result in vibrations which

adversely affect plants, machines and sen-

sitive devices and thus affect the quality of

the products. In many applications it is not

possible to wait until environmental influ-

ences dampen the vibration and bring it to

a halt; moreover, several interferences usu-

ally overlap in time, resulting in a quite con-

fusing vibration spectrum with a variety of

frequencies.

The vibrations must therefore be insulated

in order to dynamically decouple the ob-

ject from its surroundings and thus reduce

the transmission of shocks and solid-

borne sound. This increases the precision

of measuring or production processes

and the settling times reduce significant-

ly, which means higher throughputs are

possible. Piezoelectric components can

dampen vibrations particularly in the low-

er frequency range, either actively or pas-

sively.

Passive Vibration Insulation

Elastic materials absorb the vibrations and

reduce them. Piezo elements can also be

used for this: They absorb the mechani-

cal energy of the structural vibrations and

convert it into electrical energy at the same

time. This is subsequently converted into

heat by means of parallel electrical resistors,

for example.

Passive elements are installed as close to

the object to be decoupled as possible.

The conventional passive methods of vibra-

tion insulation are no longer sufficient for

many of today’s technologies. Movements

and jolts caused by footfall, fans, cooling

systems, motors, machining processes etc.

can distort patterns e.g. when micromachin-

ing to such an extent that the result is un-

usable.

Active Vibration Insulation

In this process, counter-motions compen-

sate or minimize the interfering vibrations,

and they do this as close to the source as

possible. To this end a suitable servo loop

must initially detect the structural vibrations

before the counter-motions are actively

generated.

Adaptive materials, such as piezoceram-

ic plates or disks, can act as both sensors

and actuators. The frequency range and the

mass to be damped determine the choice of

suitable piezo actuators. This also requires

an external voltage source and suitable

control electronics.

Multilayer ceramic construction produces

increased efficiency. Multilayer piezoelec-

tric actuators, such as the PICMA multilayer

translators, for example, can be used any-

where where precisely dosed alternating

forces are to act on structures.

The main application fields are in aero-

nautics and aerospace, where fuel must

be saved, for example, or the oscillations

of lattice constructions for antennas are to

be damped. One of the objectives when

building vehicles and ships is to minimize

noise in the interior. In mechanical engineer-

ing for example, the vibrations of rotating

drives are increasingly being insulated and

actively suppressed.

Vibration Control

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Industrial Applications of the Future

The development of adaptive systems is

increasing in significance for modern in-

dustry. Intelligent materials are becoming

more and more important here, so-called

“smart materials“ which possess both sen-

sor and actu ator characteristics. They detect

changed environmental conditions such as

impact, pressure or bending loads and react

to them.

Piezo ceramics belong to this group of

adaptive materials. The piezoelectric Dura-

Act patch transducers provide a compact

solution. They are based on a thin piezo-

ceramic film which is covered with elec-

trically conducting material to make the

electrical contact and are subsequently

embedded in an elastic polymer composite.

The piezoceramic element, which is brittle

in itself, is thus mechanically preloaded and

electrically insulated and is so robust that it

can even be applied to curved surfaces with

bending radii of only a few millimeters.

The transducers are simply glued to the cor-

responding substrate or already integrated

into a structure during manufacture, where

they detect or generate vibrations or contour

deformations in the component itself. The

size of the contour change here is strong-

ly dependent on the substrate properties

and ranges from the nanometer up into the

millimeter range.

Even under high dynamic load the construc-

tion guarantees high damage tolerance, reli-

ability and a lifetime of more than 109 cycles.

They have low susceptibility to wear and

defects because the transducers are solid

state actuators and thus do not contain any

moving parts.

Adaptive Systems, Smart Structures

A deformation of the substrate gives rise to an

electrical signal. The DuraAct transducer can

therefore detect deformations with precision

and high dynamics.

To dispense with the need for batteries and

the associated servicing work, it is possible

to use energy from the surrounding environ-

ment. Piezo elements convert kinetic energy

from oscillations or shocks into electrical

energy.

The robust and compact DuraAct trans-

ducers can also be used here. Deformations

of the substrate cause a deformation of the

DuraAct patch transducer and thus gener-

ate an electrical signal. Suitable transducer

and storage electronics can thus provide a

decentralized supply for monitoring systems

installed at locations which are difficult to

access.

Energy from Vibration – Energy Harvesting

The DuraAct patch transducer contracts when a

voltage is applied. Attached to a substrate it acts

as a bender element in this case.

U U

PIEZO TECHNOLOGY

Ultrasonic applications for the machining

of materials are characterized mainly by

their high power density. The applications

typically take place in resonance mode in or-

der to achieve maximum mechanical power

at small excitation amplitude.

The ferroelectric “hard“ PZT materials are

particularly suitable for these high-power

ultrasonic machining applications. They

exhibit only low dielectric losses even in

continuous operation, and thus consequent-

ly only low intrinsic warming.

Their typical piezoelectric characteristics

are particularly important for the high me-

chanical loads and operating field strengths:

Moderate permittivity, large piezoelectric

coupling factors, high mechanical quality

factors and very good stability.

Ultrasound for Bonding:

Joining Techniques

Ultrasonic bonding processes can be used

to bond various materials such as thermo-

plastics, and metallic materials like aluminum

and copper and their alloys. This principle is

used by wire bonders in the semiconductor

industry and ultrasonic welding systems, for

example.

The ultrasonic energy is generated primarily

via mechanically strained piezo ring disks,

amplified by means of a so-called sonotro-

de and applied to the bond. The friction of

the bonding partners then generates the

heat required to fuse, or weld, the materials

together around the bond.

Shaping by Machining

Apart from the welding processes, the ul-

trasonic processing of hard mineral or cry-

stalline materials such as ceramic, graphite

or glass, especially by ultrasonic drilling or

machining, like vibration lapping, is increas-

ingly gaining in importance.

This makes it possible to produce geometri-

cally complex shapes and three-dimensional

contours, with only a small contact pressure

being required. Specially shaped sonotrodes

are also used here as the machining tool.

Ultrasonic Machining of Materials

Sonar Technology and Hydroacoustics

Sonar technology systems (sonar = sound

navigation and ranging) and hydroacou-

stic systems are used for measuring and

position-finding tasks especially in mari-

time applications. The development of

high-resolution sonar systems, which

was driven by military applications, is now

increasingly being replaced by civil applica-

tions.

Apart from still used submarine positioning

sonars, systems are used for depth measu-

rements, for locating shoals of fish, for sub-

surface relief surveying in shallow waters,

underwater communication, etc.

A diverse range of piezo components is

used, ranging from the simple disk or

plate and stacked transducers through

to sonar arrays which make it possible

to achieve a linear deflection of the directivi-

ty pattern of the ultrasonic wave.

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1992

1994

1998

2001

1987

1970

1991

1993

The PI Group Milestones

A SUCCESS STORY

PIEZO TECHNOLOGY

2004

2015

2002

2011

2014

2007

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CAT125E R3 Piezoelectric Ceramic Products 12/2016. 0; Subject to change without notice. © Physik Instrumente (PI) GmbH & Co. KG 2016

All contents, including texts, graphics, data etc., as well as their layout,

are subject to copyright and other protective laws. Any copying, modi-

fication or redistribution in whole or in parts is subject to a written

permission of PI.

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. Illustrations may differ from the original and are not bind-

ing. PI reserves the right to supplement or change the information

provided without prior notice.

Headquarters

GERMANY

PI Ceramic GmbH

Lindenstrasse

Lederhose

Phone +49 36604 882-0

Fax +49 36604 882-4109

info@piceramic.com

www.piceramic.com

Physik Instrumente (PI)

GmbH & Co. KG

Auf der Roemerstrasse 1

76228 Karlsruhe

Phone +49 721 4846-0

Fax +49 721 4846-1019

info@pi.ws

www.pi.ws

PI miCos GmbH

Freiburger Strasse 30

Eschbach

Phone +49 7634 5057-0

Fax +49 7634 5057-99

info@pimicos.com

www.pi.ws

Subsidiaries

USA (East) & CANADA USA (West) & MEXIKO

PI (Physik Instrumente) L.P.

Auburn, MA 01501

www.pi-usa.us

PI (Physik Instrumente) L.P.

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www.pi-usa.us

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PI (Physik Instrumente) L.P.

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www.physikinstrumente.co.uk

ITALY NETHERLANDS

Physik Instrumente (PI) S. r. l.

Bresso

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Vilanova i la Geltrú

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JAPAN

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Tokyo

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PI Japan Co., Ltd.

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(PI Shanghai) Co., Ltd.

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TAIWAN

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For ID / MY / PH / SG / TH / VNM

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PI_CAT125E_R3_Piezoelectric_Ceramic_Products Fundamentals of Piezo Technology

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