Appearance of an electric potential across certain faces of a crystal when it is subjected to mechanical pressure

1. Presented To: RETHWAN FAIZ
Group Members:
FARHIN, REHNUMA 14-25520-1
MIRAZ, MAGFURUL AWWAL 14-25537-1
AHMED, MD. FOYSAL 14-25539-1
CHOWDHURY, TULSI 14-25727-1
MUIN, MUHTASIM 14-25600-1
RAHMAN, MD. RABBI 14-26318-1

2. Content
 What is Piezoelectricity
 What is Piezoelectric materials
 Mechanism of Piezoelectric
 Motion of Piezoelectric Actuators
 Common Piezoelectric materials
 Configurations
 Hardware Features
 Applications of Piezoelectric
 Advantages and Disadvantages
 Artificial materials
 Signal Conditioning
 Conclusion

3. What is Piezoelectricity ?
 Piezoelectricity is the electric charge that accumulates
in certain solid materials in response to applied
mechanical stress. The word Piezoelectricity means
electricity resulting from pressure.
 The larger circles represent silicon atoms, while the
smaller ones represent oxygen.

4. What is Piezoelectric?
Piezoelectric:
 Piezoelectrics are materials that can create electricity when
subjected to a mechanical stress.
 They will also work in reverse, generating a strain by the
application of an electric field.
 The word originates from the greek word “piezein”, which
means “to press”. Discovered in 1880 by Pierre Curie in
quartz crystals

5. Mechanism of Piezoelectric
 The nature of the piezoelectric effect is closely related to the
occurrence of electric dipole moments in solids. The latter may
either be induced for ions on crystal lattice sites with asymmetric
charge surroundings or may directly be carried by molecular
groups. The dipole density or polarization (dimensionality
[Cm/m3] ) may easily be calculated for crystals by summing up
the dipole moments per volume of the crystallographic unit cell.
As every dipole is a vector, the dipole density P is a vector field.
Dipoles near each other tend to be aligned in regions called
Weiss domains. The domains are usually randomly oriented, but
can be aligned using the process of poling, a process by which a
strong electric field is applied across the material, usually at
elevated temperatures. Not all piezoelectric materials can be
poled.

6. A piezoelectric disk generates a voltage when
deformed (change in shape is greatly
exaggerated)

7. • Shear actuators
• Disk bimorph
• Bimorph blenders

8. Common Piezoelectric Materials

9. • Red indicates the crystal
• Arrows indicate the direction of applied force
• The compression design features high rigidity, making it useful for
implementation in high frequency pressure and force sensors

11. • Infineon C164CI 16 bit Processor
• 20 MHz clock rate
• 256kB SRAM
• 256kB Flash ROM
• CAN 2.0B controller
• 250 kbps raw data rate
• RS-232 Interface
• 115.2 kbps UART
• DB-9 serial interface
• 3 channel LISA interface
• Left, Right, and microphone channels
• Optional pre-amp for microphone

12. Applications of Piezoelectric
 Power generating sidewalk
 Gyms and workplaces
 Mobile keypads and keyboards

13. Applications of Piezoelectric

14. Applications of Piezoelectric

15. Applications of Piezoelectric

16.  Polycrystalline, piezoceramics are man made
materials which are forced to become piezoelectric
by applying large electric field.
 High charge sensitivity
 Materials available which operate at 1000 F (540
C)
 Characteristics vary with temperature

18. Advantages and Disadvantages

19. • 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.

20. Thank You