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)
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
10.
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
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
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.