This document summarizes nanogenerators, which are piezoelectric transducers at the nanoscale that harness mechanical energy and convert it to electrical energy. Dr. Zhong Lin Wang and his colleagues at Georgia Tech have made significant advances in developing nanogenerators using zinc oxide nanowires over the last decade. Nanogenerators consist of a base electrode, piezoelectric nanostructures such as ZnO nanowires, and a counter electrode. When the nanowires are bent or flexed, a voltage is generated via the piezoelectric effect. Nanogenerators have applications powering small electronics and can harvest energy from tiny motions like heartbeats or footsteps.

1. NANOGENERATOR
Navin Kumar
09EAXEC075

2. Piezoelectric Transducer
• Ability to create electrical potential when compressed,
expanded or changed in shape (Mechanical energy to
Electrical energy).
• The voltage generated can be quiet high.
• Made up of piezoelectric
crystals like quartz and
topaz.
• Unaffected by external
electromagnetic fields.
• Can be used both as
generators and actuators.

3. Introduction

4. Developers of Nanogenerators
Dr. Zhong Lin (Z.L.) Wang and his colleagues at Georgia Institute of Technology,
Georgia State, USA have made significant leaps in developing nanogenerators
over the last decade.

5. A Nano Scale Piezoelectric Transducer
(Nanogenerator)
• Harnesses the body's energy.
• Made of Zinc Oxide (ZnO) wires called Nanowires.
• Produces 45 millivolts whenever the zinc wire is pulled
back and forth.
• With simultaneous output from many nanowires, we
can generate high
power.
• The wires have a
diameter of 100 to
300 nm and length of
about 10 to 100
micron.

6. Inside A Nanogenerator
• Consists of an integrated
circuit.
• Components are made from
ITO (Indium tin oxide) and a
piezoelectric ceramic.
• Nanowire bends and generates
an electrical charge.
• ITO electrode captures that
charge.
• Several electrodes capture
power from millions of
nanowires.

7. Inside A Nanogenerator
• Piezoelectric effect creates
an electrical field inside the
nanostructure.
• Relative displacement of
cations with respect to
anions in its crystalline
structure.
Potential distribution for a ZnO NW at
a lateral bending force of 80
nanonewtons is shown.

8. Working Principle
• Generates DC

9. Working Principle
• Generates AC

10. Types of Nanogenerators

11. 1. Vertical nanowire Integrated Nanogenerator
(VING)
• 3 parts :
a. base electrode,
b. vertical piezoelectric
nanostructure, &
c. counter electrode.
• Nanowires grown from
the base electrode to
the counter electrode.
• Counter electrode
motion induces the
deformation of the
nanowire.

12. 2. Lateral nanowire Integrated Nanogenerator
(LING)
• 3 parts :
a. base electrode,
b. lateral piezoelectric nanostructure, &
c. counter electrode.
• Integrated on a
flexible substrate.
• Individual
NW is subjected to
high tensile strain.
• Allows for
amplification by
series connection
of units.

13. DC Nanogenerator Driven by Ultrasonic Waves
• Integrating a Platinum
(Pt) coated electrode
with vertically aligned
ZnO NW.
• Pt enhances the
conductivity of the
electrode.
• Nanowire arrays were
placed beneath a
zigzag metal
electrode with a small
gap.

14. DC Nanogenerator Driven by Ultrasonic Waves
• Top electrode moves
downward and
pushes the NW
leading to a lateral
bending.
• Due to the rectifying
action caused by
partial contact, the
output electric signal
exhibits a DC
characteristic.

15. Sources which Nanogenerators can exploit
• For Large scale applications (from wherever periodic
kinetic energy exists) :
1. Wind,
2. Ocean Waves.
• Small scale applications :
1. Tiny physical motion,
2. Inhalation of lung,
3. Heartbeat,
4. Muscle movement,
i.e. Any kind of movement!!

16. Applications
• Powering conventional electronics :
1. Light Emitting Diode (LED),
2. Liquid Crystal Display (LCD), and
3. Laser Diode.
• To power your personal gadgets
and phones.
• Self-powered nano/micro
devices.
• Implantable power devices.
• Smart Wearable Systems.

17. Applications
• Smart Wearable Systems – Power Shoes

18. Applications
• Smart Wearable Systems – A Power Shirt

19. THANK YOU