1. Piezoelectric and Pyroelectric Properties of Polymers

2. Contents Polymers Classifications Properties of Polymers
Electrical Properties
Piezoelectricity
Pyroelectricity

3. Polymers
A polymer is a large molecule(macromolecule) composed of repeating structural units.
These sub units are typically connected by covalent chemical bond.

4. Polymer Building Blocks
Hydrogen
Carbon (key)
Oxygen
Nitrogen
Fluorine
Silicon
Sulfur
Chlorine

5. Classifications of Polymers
Linear polymer
Branch and cross-linked polymers
Homo polymers, co-polymers and alternate co-polymers
Cristalline, amorphous and semi cristalline polymers
Polar and non-polar polymers

6. Properties of polymers
Electrical properties
Mechanical properties
Physical properties
Chemical properties

8. Piezoelectricity
Jacques Curie
The word is derived from the Greek piezein, which means to squeeze or press.
The effect known as piezoelectricity was discovered by brothers Pierre and Jacques Curie when they were 21 and 24 years old in 1880.
Piezoelectric Effect is the ability of certain materials to generate an electric charge in respond to applied mechanical stress.
Pierre

10. The work in the area of piezoelectric polymers has led to the development of strong piezoelectric activity in polyvinylidene fluoride (PVDF) and its copolymers with trifluoroethylene ( TrFE) and tetrafluoroethylene (TFE).
These semicrystalline fluoropolymers represent the state of art in piezoelectric polymers.

11. Pyroelectricity
The word is derived from the Greek pyr, which means to fire.
The pyroelectricity discovered by David Brewster in 1824.
Pyroelectricity is the ability of certain materials to generate a temporary voltage when they are heated or cooled.
The change in temperature modifies the position of the atoms slightly within the crystal structure, such that the polarization of the material changes.
This polarization changes gives rise to a voltage across the crystal. If the temperature stays constant at its new value, the pyroelectric voltage gradually disappears due to leakage current.

12. Pyroelectric charge in minerals develops on the opposite faces of the asymmetric crystals. The direction in which the propagation of the charge tends toward is usually constant through a pyroelectric material, but in some material this direction can be changed by a nearby electric field. These materials are said to exhibit ferroelectricity.
All pyroelectric materials are also piezoelectric, however some piezoelectric materials have a crystal symmetric that does not allow pyroelectricity.

13. Classes of Pyroelectric Polymer

14. Piezometer System

15. Force Set
Probes
Piezo-material

17. Piezoelectric Constants

18. Comparison of piezoelectric properties of some semicrystalline polymeric materials

19. Applications and Future Considerations
The application potential for piezoelectric and other electroactive polymers is immense. To date, ferroelectric polymers have been incorporated into numerous sensing and actuation devices for a wide array of applications. Typical applications include devices in medical instrumentation, robotics, optics, computers, and ultrasonic, underwater and electroacoustic transducers.
One important emerging application area for electroactive polymers is in the biomedical field where polymers are being explored as potential artificial muscle actuators, as invasive medical robots for diagnostics and microsurgery, as actuator implants to stimulate tissue and bone growth, and as sensors to monitor vascular grafts and to prevent block ages. Such applications are ideal for polymers since they can be made to be biocompatible and they have excellent conformability and impedance matching to body fluids and human tissue.