INTRODUCTION

GENERATING ELECTRICITY USING PIEZOELECTRIC EFFECT

BYM.SANJEEV KUMAR (11J41AO269)

INTRODUCTIONPiezoelectricity was discovered by Curie brothers in 1880.The name Piezo originates from the Greek word piezein, which means to squeeze or press.

PIEZOELECTRIC EFFECT

Appearance of an electric potential across certain faces of a crystal when it is subjected to mechanical pressure.Conversely, when an electric field is applied to one of the faces of the crystal it undergoes mechanical distortion.

The crystals become polarized and produce an emf or voltage that is proportional to the amount of force

PIEZOELECTRIC EFFECT

WHAT IS A CRYSTAL?A class of materials arranged in a definite pattern in three dimensions (quartz and Rochelle Salt common examples).

All non centrosymmetric crystals are exhibits piezoelectric effect.

MATERIALS

NATURALSYNTHETICQuartzLead zirconate titanate (PZT)Rochelle SaltZinc oxide (ZnO)TopazBarium titanate (BaTiO3)SucroseGallium orthophosphate (GaPO4)TendonPotassium niobate (KNbO3)SilkLead titanate (PbTiO3)EnamelLithium tantalate (LiTaO3)DentinLangasite (La3Ga5SiO14)DNASodium tungstate (Na2WO3)

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Without any external stress-Centers of charges coincide-charges are reciprocallycancelled-electrical neutral unit cell

Applied external stress-Internal structure is deformed.separation of charge centers.dipoles are generated.

MATHEMATICAL EXPRESSION

POWER GENERATING SIDEWALK

Charging of mobile using vibrations & soundZinc oxide nano wires converted sound-caused vibrations into electricity.Scientists from Nokia and Queen Mary University of London have succeeded in doing so.

GYMS AND WORKPLACESVibrations caused from machines in the gym.At the workplaces, piezoelectric crystal are laid in the chairs for storing energy.Utilizing the vibrations in the vehicle like clutches, gears etc.

Recently piezoelectric floors have debuted in a handful of innovative dance clubs around the world.

APPLICATIONS

APPLICATIONS

Sound waves striking a PZ material produce an electrical signal2. Can be used to detect sound (and echoes)!

ADVANTAGESDISADVANTAGESUnaffected by external electromagnetic fields.

May get affected by long use at high temperatures

Pollution Free

Crystal is prone to crack if overstressed.

Low Maintenance

Can pick up stray voltages in connecting wires

Easy replacement of equipment.

CONCLUSIONPiezoelectricity 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.

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