The document provides a comprehensive overview of piezoelectric ceramics, including their definition, fabrication, processing methods, types, applications, and advantages and disadvantages. Piezoelectricity is the ability of certain materials to generate an electric charge in response to mechanical stress, and this effect can be used in various applications like sensors, actuators, and energy harvesting. Key production steps involve mixing metal oxides to achieve a dense crystalline structure, and specific operational limits must be adhered to prevent depolarization.

1. Seminar And Technical Writing on
“Piezoelectric Ceramics Or Piezoceramics”
Presented to— Presented by-
Prof.Debasish Sarkar Abhisek Das
120CR0391

2. Outline->
1.Introduction
2.Fabrication
3.Processing
4.Types
5.Applications
6.Advantages & Disadvantages
7.Conclusion
8.Reference

3. Introduction
 What is piezoelectric?
Pizo or piezein > squeeze or press and
electron > amber, an ancient source of electric charge.
» Piezoelectricity is a concept of conversion of mechanical energy to electrical
energy and viceversa, not by any electromagnetic principle but by the process of
Polarization.
» Piezo-electricity, or pressure electricity, is defined as polarization induced by
the application of external force.

4.  Piezoelectricity is the ability of some materials to generate an electric charge
in response to applied mechanical Stress.
 The piezoelectric effect is reversible.
 Direct piezoelectric effect: charge separation due to stress.
 converse piezoelectric effect: occurence of stress and strain when electric
field is applied.
 Happens in insulating materials, Insulating Ferroelectric materials with
a permanent dipole, In crystals(only crystals without symmetry centre) .

5. The microscopic origin of the piezoelectric effect is the displacement of
ionic charges within a crystal structure.
 In the absence of external strain, the charge distribution is symmetric and the
net electric dipole moment is zero.
 However when an external stress is applied, the charges are displaced and
the charge distribution is no longer symmetric and a net polarization is
created.
 In order to create a net piezoelectric effect, the material must be:
a. a pure crystal (difficult to realize in most cases)
b. the crystal domains must be brought into alignment during poling .

6. Operational Limits Of piezoelectric
Materials
 During normal operation, a piezoelectric material is either strained
(to create an electric potential) or is subjected to an electric
potential (to create a strain).
 However, care must be taken to operate the material within the
parameters specified by the manufacturer.
 Electrical depolarization can occur if a piezoelectric material is
subjected to extreme electric fields (or voltages) which will cause it
to lose (or significantly degrade) its piezoelectric effects.
 Mechanical depolarization can occur if a material is excessively
strained to the point where the crystal domains are significantly
disturbed.
 Thermal depolarization can occur if a material subjected to
temperatures beyond the *Curie point” of the material.

7. How are Piezoelectric ceramics made?
 Fine powders of the component metal oxides are mixed in specific
proportions, then heated to form a uniform powder.
 The powder is mixed with an organic binder and is formed into
structural elements.
 The elements are fired according to a specific time and temperature
program, during which the powder particles sinter and the material
attains a dense crystalline structure.
 The elements are cooled, then shaped or trimmed to specifications.
Electrodes are applied to a conducting material, which is connected
to the elements.

8. Crystal Structure and Dipole Moments
 A traditional piezoelectric ceramic is a mass of
perovskite crystals.
 Each crystal consists of a small tetravalent metal
ion, usually titanium or zirconium, in a lattice of
larger divalent metal ions, usually lead or barium,
and 02~ ions.
 At temperatures below the Curie point, however,
each crystal has tetragonal or rhombohedral
symmetry and a dipole moment.
 Above the Curie point each perovskite crystal in
the fired ceramic element exhibits a cubic
symmetry with no dipole moment.

9. Processing of Piezoelectric Ceramic

10. Types of Piezoelectric Materials
 1. Naturally occurring crystals: Berlinite (AIPO4), cane sugar, Quartz,
Rochelle
salt, Topaz, Tourmaline Group Minerals, and dry bone (apatite crystals)
 2. Man-made crystals: Gallium orthophosphate (GaPO4), Langasite
(La3Ga5Si014)
 3. Man-made ceramics: Barium titanate (BaTiO3), Lead titanate
(PbTiO3),Lead zirconate titanate - more commonly known as PZT,
Potassium niobate (KNbO3), Lithium niobate (LiNbO3), Lithium
tantalate (LiTaO3)
 4. Polymers: Polyvinylidene fluoride (PVDF)

11. Impact of Piezoelectric Materials

12. Applications of Piezoelectric ceramics
 The principle is adapted to piezoelectric motors, sound or ultrasound
generating devices, and many other products.
 Generator action is used in fuel-igniting devices, solid state batteries, and
other products.
 Motor action is adapted to piezoelectric motors, sound or ultrasound
generating devices, and many other products.
 Generators Sensors Actuators Transducers .
 Transducers: convert mechanical energy into electrical energy (or vice versa)
e.g. Mechanical to electrical: record player, strain gauge. cigarette lighter.
e.g. Electrical to mechanical: production of ultrasonic waves.

14. Implementation Of Piezoelectricity In
Practical life
 Energy Harvesting: Vibrations from industrial machinery can also be harvested
by piezoelectric materials to charge batteries for backup supplies or to power
low-power microprocessors and wireless radios.
 Piezoelectric elements are also used in the detection and generation of sonar
waves.
 Inkjet printers: On many inkjet printers, piezoelectric crystals are used to
drive the ejection of ink from the inkjet print head towards the paper.
 Diesel engines: High-performance common rail diesel engines use
piezoelectric fuel.
 injectors, first developed by Robert Bosch GmbH, instead of the more
common solenoid valve devices.

15.  Piezoelectric motors: Piezoelectric elements apply a directional force
to an axle, causing it to rotate. Due to the extremely small distances
involved, the piezo motor is viewed as a high-precision replacement
for the stepper motor.
 A recent application of piezoelectric ultrasound sources is
piezoelectric surgery also known as piezosurgery.Piezosurgery is a
minimally invasive technique that aims to cut a target tissue with
little damage to neighboring tissues. It has the ability to cut
mineralized tissue without cutting neurovascular tissue and other soft
tissue, thereby maintaining a blood-free operating area, better
visibility and greater precision.
 Ultrasonic piezo-sensors are used in the detection of acoustic
emissions in acoustic emission testing.

16. Advantages & Disadvantages

17. Conclusion
 Piezoelectricity is a revolutionary source for “GREEN ENERGY” .
 Flexible piezoelectric materials are attractive for power harvesting
applications because of their ability to withstand large amounts of
strain.
 Convert the ambient vibration energy surrounding them into electrical
energy.
 Electrical energy can then be used to power other devices or stored
for later use.

18. References
 "Introduction to Ceramics" by W.D. Kingery, H.K. Bowen, and D.R. Uhlmann.
 "Piezoelectric Ceramics" by A. Safari and S. Safari.
 Fundamentals of Piezoelectric Sensorics: Mechanical, Dielectric, and
Thermodynamical Properties of Piezoelectric Materials" by B. Jaffe, W. R.
Cook, and H. Jaffe. (Journal of the Acoustical Society of America).
 "Review of the piezoelectric properties of ceramics with perovskite
structures" by A.S. Bhalla, L.E. Cross, and R. Roy. (Journal of the American
Ceramic Society).

19. THANK YOU!!