In order to tackle the increasing global energy consumption and consumers, we need to develop and implement efficient, clean, and renewable power sources. This presentation's objective is to introduce an alternative source of energy by using piezoelectric materials.

1. Presented by:
Rohan Choudhury &
Shreyan Datta

2. Conventional technologies of harvesting energy may have high
efficiencies in meeting the demand, but have a significant impact on the
environment and resources.
● Fossil fuels like coal, oil, petroleum, natural gas and liquified
petroleum gas (LPG) are not sustainable in nature.
● The usage of fossil fuels which are carbon-intensive in their
composition, involves the emission of carbon dioxide, a
greenhouse gas.
Thus, nowadays, most of the research in the field of energy harvesting is
to develop alternative sources of energy that are renewable and do not
involve environmentally damaging techniques in the process of their
retrieval.

3. ● Paul-Jacques Curie and Pierre Curie discovered the Piezoelectric
effect in 1880.
● They found it in crystals like tourmaline, quartz, topaz, cane sugar
and Rochelle salt.
● First applications were made during World War I with piezoelectric
ultrasonic transducers (used in SONAR for submarines).
HISTORY
Paul Curie and Jacques Curie

5. WHAT IS IT?
● The Piezoelectric Effect refers to a change in electric polarization that is produced in
certain materials when they are subjected to mechanical stresses.
● This stress-dependent change in polarization manifests as a measurable potential
difference across the material.
● Referred to as the direct piezoelectric effect, this phenomenon is observable in many
naturally available crystalline materials, including quartz, Rochelle salt, and even
human bone. Engineered materials, such as lithium niobate and lead zirconate titanate
(PZT), exhibit a more pronounced piezoelectric effect.
● The inverse piezoelectric effect refers to a deformation of these materials that results
from the application of an electric field.

6. a. Unperturbed molecule
b. Molecule subjected to an external force
c. Polarizing effect on the material surfaces

7. ● A piezoelectric material produces an electric charge when the
substance is subjected to a mechanical stress. Each molecule is
polarized, where one end is more negatively charged and the other
end is positively charged.
● In a monocrystal, the polar axes of all of the dipoles lie in one
direction.
● Whereas, in a polycrystal, there are different regions with different
polar axes.
● A monocrystal is symmetrical, and a polycrystal is asymmetrical.
● In order to harvest the piezoelectric effect, the polycrystal is heated
up using a strong electric field. Molecules get heated up due to the
electric field which then forces the dipole to align almost in the same
direction.

8. Arrangement of dipoles in Monocrystal

9. Arrangement of dipoles in Polycrystal

10. This is the general working circuit of a single piezo plate generator, or transducer. We
pass the alternating current through a full wave bridge rectifier to convert it into
Direct current. Then we store this energy by means of capacitor, which can be later
discharged by a load, thus providing electricity to the load applied.

18. Piezoelectric generators can be simply
placed underneath floor tiles, which can
help in harvesting energy when anyone
steps on it.
This can be very much effective in public
places like
supermarkets, shopping complexes, and
parks. The money saved on energy
consumption can then be invested in
maintenance thus elevating the standard
and
appeal of the place concerned.

19. 1. Movement of vehicles are always constant on busy roads and
highways so, power can be generated constantly by this concept.
2. Power generated from ‘Piezo-smart roads’ concept is Greenpower
and no harm to the environment.
3. This power can be very well utilized for the street lightning and other
small scale purposes.
4. This source of electrical energy is a long term investment having
merits of being a continuous source, independent and unaffected by
climatic conditions.

20. 1. Implementing this concept is a little bit tedious.
2. The present day roads need to be relayed again in order to implement
this concept.
3. This will result in traffic congestions all over the city and needs a critical
plan of implementation and management.

22. ● The concept doesn’t involve any exclusive input requirements, as
it is just harvested by the consumers themselves without any
participation.
● But, this concept has got some limiting issues when it comes to
practically implementing them in structures in the real world.
● With further study and research over the years the limitations
could be overcome and the long-term benefits surely are worth
enough for enduring the shortcomings temporarily.
● Thus, this concept of the overall method manifests a promising
solution to the existing energy crisis.