This document discusses piezoelectricity and its use in energy harvesting. It begins with a brief history of piezoelectricity's discovery. It then explains the basic components and working principle of a piezoelectric energy harvesting circuit using diodes, a capacitor, switch, and LED. Applications discussed include using piezoelectric sensors in floors, gym equipment, vehicles, keyboards to harvest vibration energy. Both advantages like being pollution-free and disadvantages like low output are summarized. The document concludes that piezoelectric energy harvesting is a promising green energy source.

1. BY- AVILASH PAUL , SOUGATA ROY

2.  INTRODUCTION
 MATERIALS NEEDED
 CIRCUIT DIAGRAM
 WORKING PRINCIPAL
 APPLICATION
 ADVANTAGES &
 DISADVANTAGES
 CONCLUSION

3.  Piezoelectricity was discovered by Curie brothers in
1880.
 It is the generation of electric field from applied
pressure.
 It is observed in crystalline material with no inversion
symmetry.
 The internal generation of a mechanical strain
resulting from an applied electrical field.

4.  PIEZOELECTRIC SENSOR
 4 DIODES
 CAPACITOR
 SWITCH
 LED
 BATTERY

6.  The positive & negative charges are symmetrically distributed
in a crystal.
 Piezoelectric sensor are not piezoelectric until the random
ferroelectric domains are aligned by a process known as
poling.
 Poling consists of inducing a dc voltage across the material.

7.  When pressure is applied on the piezoelectric sensor
a negative charge is produced .
 The charge goes through the rectifier which rectified
the charge AC to DC .
 The capacitor is used to stabilized the charge .
 When the circuit is closed the charge pass through
the capacitor and from the switch as a result the LED
will glow.

10.  Charging pad (piezoelectric
sensor) are under the
footpaths collecting the
energy from the vibration.
 Charging pads are connected
with lithium ions
batteries(which can be used
further)

11.  Vibration caused by the
machines in gym.
 At work place
piezoelectric sensors are
laid on the chairs.
 Using the vibration of the
vehicle like clutches and
gears etc.

12.  Piezoelectric crystals
are laid under the
mobile key and
keyboard.
 For every key vibration
created .
 These vibration can be
use for charging
purpose.

13.  Idea was researched in USA.
 To power the battle field
equipment by generators
embedded in the soldiers
boots.
 The idea then abounded due
to discomfort.
 Boots with comfort and with
this features are invented.

14.  The output voltage from one piezoelectric crystal in
millivolts(mv) range , which is different for different
crystals .
 And the wattage is microwatt range.
 In order to achieve greater voltage piezoelectric
crystal can be placed in series.
 Use charged batteries for backup supplies.

15.  It is unaffected by external magnetic field.
 It is pollution free.
 It has low maintenance.
 Easily replacement of equipments.
 It is small in size.
 It has good frequency response.

16.  It can’t be used for truly static measurements.
 Temperature sensitivity.
 It can be cracked if overstress is applied.
 The crystal give off voltage but it’s not a battery.
There is very little energy available.
 May get effected by long use in high temperature.

17.  Piezoelectric is a very revolutionary source of green
energy.
 With low cost energy can be generated and without
polluting the environment.
 It can be used on daily basis converting the
surrounding vibrating energy to electrical energy.
 And can be used for other works or can be stored for
further uses.