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Direct Piezoelectric

 Actuators

Brandon Withers

ECE 5320 Mechatronics

 Assignment #1

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Outline

Major Applications

History of Piezoelectricity

Piezomaterials

Characteristics of Piezoactive Materials

Piezoelectric Actuator Possibilities PI PT120-140 Piezoceramic Tubes

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To Explore Further

Piezo Tutorials-- http://www.piezo.com/appdata.html 

-- http://www.morganelectroceramics.com/piezoguide8.html 

Manufacturers of Piezoelectric Actuators-- http://www.adaptronics.com 

-- http://www.morganelectroceramics.com 

-- http://www.piezo.com 

-- http://www.physikinstrumente.de/products/index.php 

Great Site With Many Links to Web DocumentsDealing With Piezoelectronics

-- http://citeseer.nj.nec.com/528109.html 

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Major Applications

Fiber alignment switching, splicing and

stretching modulation

Micro-assembly and micro-handling systems Micro-embossing

Laser cavity tuning/stabilization

Beam steering/alignment Ultrasonic welding

Ultrasonic cleaning

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History of Piezoelectricity

1880 – Curie brothers first examined the piezoelectriceffect on crystal materials which have the ability toproduce electrical charges in response to externally

applied forces. This is called the direct effect and isreciprocal so that the piezoelectric material also changesits dimensions under applied electrical charges.

1922 – Langevin proposed the first Actuator based oncrystal materials.

Late 1960s – Discovery of PZT (lead titanium-zirconate)increased the number of applications.

1988 – First market use of multilayer actuators (MLAs)derived from the high capacitor technology.

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PiezomaterialsMaterials that exhibit a significant and useful piezoelectric effect fall

into three main groups:

 Crystals

- Natural (quartz, Rochelle salt)

- Synthetic (lithium sulfate, ammonium dihydrogen phosphate)

 Polarized ferroelectric ceramics (main piezomaterials for engineering

applications and must be artificially polarized)

- Lead Zirconate Titanate (PZT)

- Barium Titanate- Lead Magnesium Niobate

- Modified Lead Titanate

- Bismuth Titatnate

 Polymer fibers

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Characteristics of Piezoactive

MaterialsPiezoelectric materials are crystalline solids whose asymmetric structures

create an electric dipole moment in the crystal lattice, which is sensitive to both

elastic strain and applied electrical field.

“Piezoelectric Actuators Tutorial” 

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Characteristics of Piezoactive

Materials (cont.)PZT materials get their remnant polarization during a process known as the

poling process. During this process the material is subjected to a high electric

field at the Curie temperature and then slowly cooled with the field applied.

When a stress is applied it generates an electrical field through the inversepiezoelectric effect. Since the ceramic is a dielectric medium, the electrical

displacement is related to the electrical field by the following equations:

S = sE T + dE  

D = εT E + dT

S = strain (m) sE = compliance of the material (m2/N)

T = stress (N/m2) ε T = permittivity under constant stress (F/m)

E = electric field (V/m) d = piezoelectric constant (m/V or C/N) 

D = dielectric displacement (C/m2)

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Characteristics of Piezoactive

Materials (cont.)

“The Mechatronics Handbook” 

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Piezoelectric Actuator Possibilities

“The Mechatronics Handbook” 

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Piezoelectric Actuators Possibilities

(cont.)

“The Mechatronics Handbook” 

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PI PT120-140 Piezoceramic Tubes

 Application Examples

 Micropositioning

 Scanning, Microscopy (STM, AFM, etc.)

 Fiber Stretching / Modulation of OpticalPath Length

 Micro Pumps / Ink-Jet Printing

 Micromanipulators

 Ultrasonic and Sonar Applications

These monolithic components contract laterally

(radially) and longitudinally when a voltage is applied

between their inner and outer electrodes. Multi-

electrode tubes are available to provide XYZ motion

for use in manipulation and scanning microscopy

applications“PT120 – PT140 Piezoceramic Tubes” 

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PI PT120-140 Piezoceramic Tubes

“PT120 – PT140 Piezoceramic Tubes” 

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PI PT120-140 Piezoceramic Tubes

Tube actuators are not

designed to withstand large

forces, but their high resonant

frequencies make them

especially suitable for dynamicoperation.

“PT120 – PT140 Piezoceramic Tubes” 

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PI PT120-140 Piezoceramic Tubes

Useful Equations

“PT120 PT140 Piezoceramic Tubes”