Seminar Report on
“NANOGENERATOR”“ELECTRICITY WITH A PINCH OF FINGER”
Presented by: Akanksha Singhal
Department of Electrical
Engineering
GBPUAT Pantnagar
Electricity Scenario In India
Total installed capacity of 303 GW.
Renewable power installed capacity is 28%.
Non renewable power installed capacity is 72%.
Contribution from natural gas, oil and hydro plants has
decreased in last four years (2012-2016).
Yearly Gross energy Generation(in GWh)
Need for Alternative Energy
Sources
We mostly depend on Coal, Oil and natural gas for our
energy needs.
Fossil fuel are non renewable.
Affect environment adversely ( acid rain, ozone layer
depletion etc.)
CO₂ released causes global warming.
Damages water system.
Effects health.
Incidents like oil spill is dangerous for species.
Dependency on other regions for supply of resources.
Prevalent Alternative Energy
Sources
Hydro energy.
Nuclear energy.
Wind energy.
Solar energy.
Geothermal energy.
Biofuel.
Tidal energy.
Piezoelectricity
The first experimental demonstration of piezoelectric
effect was in 1880 by Pierre and Jacques Curie.
They subjected prepared crystals to mechanical stress.
Originally, crystals made from quartz were used as a
material for piezoelectric crystal transducers.
This effect is observed in crystals that have no centre of
symmetry.
All molecules are polarized but net electric field is zero.
On application of stress, charge separation takes place
generating electricity.
The first serious applications work on piezoelectric
devices took place during World War I.
Japanese market grew very quickly in this field.
What is Nanogenerator?
Small electronic chip.
Uses mechanical movements/thermal energy to
generate electricity.
Made up of piezoelectric ceramic material and silicon.
As the name implies, it is extremely small in size.
The name ‘Nanogenerator’ signifies that they are
used to drive nano scale devices.
Generators is about 2 mm in diameter.
Comes in Handy when use of battery is cumbersome.
Development
of
Nanogenerator
Dr. Zhong Lin Wang of the
Georgia Institute of
Technology along with his
team is a leading researcher
in nanogeneration.
He developed Nanogenerator
in the year 2006.
The device was fabricated
with piezoelectric zinc oxide
nanowire arrays.
Energy Aimed To be harvested
Mechanical energy existing in our living environment.
Characteristics:
The magnitude of energy could be small and tiny.
The frequency range of the available signal can be quite wide
Environment can vary.
Sources of energy : light wind, body movement, muscle
stretching, acoustic/ultrasonic waves, noises, mechanical
vibrations, blood flow etc.
What is a Nanowire?
A wire of nanometer dimension.
Types of nanowires :
o metallic (e.g., Ni, Pt, Au)
o semiconducting (e.g., InP, Si, GaN,
etc.)
o insulating (e.g., SiO2,TiO2).
It can be triggered by tiny physical
motions and the excitation frequency
can be one Hz to thousands of Hz.
By integrating thousands of nanowires,
1.2 V can be developed which can
drive an LED and a small liquid crystal
display.
Fabrication Of Nanowire There are various method employed for Nanowire
generation:
Vapour-liquid-solid epitaxial (VSLE) mechanism
Metal-organic chemical vapour deposition (MOCVD)
Pulsed laser deposition (PLD)
Chemical vapour deposition (CVD)
Hydrothermal synthesis
Solution phase approaches
Construction of Nanogenerator
Integrated circuit, made
from silicone and a
piezoelectric ceramic.
Etched onto a flexible
conducting surface, called
substrate.
Zno was used to develop
Nanowire.
Why ZnO is used?
Semiconducting piezoelectric
material.
energy band gap of 3.37 eV
and large excitation binding
energy of 60 meV at room
temperature.
Zno is neutral but charges can
redistribute resulting in
positively and negatively
charged surface.
Environmental friendly and
biocompatible.
Growth occurs on large
variety of substrate materials.
Crystal structure
of ZnO
TYPES OF NANOGENERATOR
TRIBOELECTRIC PIEZOELECTRIC
VING NEG LING
PYROELECTRIC
Piezoelectric Nanogenerator
Converts external kinetic energy to electric energy.
Force can be perpendicular or parallel to the axis.
When force is applied then there is relative
displacement of cations and anions.
Stretched part attains positive charge and compressed
part attains negative charge.
VING
VING stands for vertical nanowire integrated generator.
Figures below show VING type of Nanogenerator:
LING
It has the base electrode, the laterally grown
piezoelectric nanostructure and the metal electrode for
schottky contact.
It generates AC signal.
NEG
NEG consists of metal plate electrodes, vertically
grown piezoelectric nanostructure and filler polymer
material.
Higher efficiency compared to original Nanogenerator
configuration with ZnO wire.
Triboelectric Nanogenerator
Converts the external mechanical energy into electricity.
Based on electrostatic induction.
This technology was demonstrated in the year 2012.
Three modes of operation are listed below::
Vertical Contact Separation Mode
Lateral Sliding Mode
Single Electrode Mode
Vertical Contact Separation
Mode
Two dissimilar dielectric films face with each other with electrode deposited on them.
Due to force, close contact occurs causing charge transfer. This is triboelectric effect.
One Surface lifted relative to other.
When deformation released, electron flow from one electrode to other to screen potential difference.
Lateral Sliding Mode
One surface is made to slide with respect to second
surface.
Change in contact area.
This potential difference will drive a current flow from
the top electrode to the bottom electrode in order to m
aintain equilibrium.
Single Electrode Mode
More practical and feasible.
Employed when Nanogenerator can’t remain in contact
with load continuously.
Helpful when we are utilizing energy of walking.
Pyroelectric Nanogenerator
Converts external thermal energy into electrical energy.
During generation, transmission etc a lot of energy is released as heat and this energy can be utilized.
It was introduced in 2012.
Based on Seeback effect.
It is often used as self powered temperature sensor.
The voltage produced is small.
Advantages of Nanogenerator
The problems associated with the use of batteries include
limitation in the size of the device and frequent recharging
process.
Mechanical energy is always available in and around us for
powering Nano devices.
Harvests energy from random energy(which usually remains
unused) and therefore is sustainable.
Environment friendly.
Portable.
No waste disposal problem (as involved in batteries).
Medical Applications
Piezoelectric Nanogenerator can convert the kinetic
energy of the heart during the contractions and
relaxations of the muscles to electric energy.
Can be used as cardiac function monitor.
Wearable medical electronic devices such as
implantable cardioverter defibrillators (ICD), left
ventricular assist devices (LVAD), and total artificial
hearts (TAH) etc. can be powered using it.
ICD
LVAD
Implantable Cardio
Defibrillator
Small device that are placed in the chest or abdomen.
To help treat irregular heartbeats.
Arrhythmia is a problem in ventricles (lower chambers of
heart) during which heart is not able to pump blood.
This is treated right away with an electric shock to the
heart. This treatment is called defibrillation.
Nanogenerator can be used to power the defibrillator.
Pacemaker can also be powered using it for minor problems.
When the battery exhausts, patients have to receive surgical
operations again to replace the battery of a device, causing
the patients physical pain. This is elimated by using
nanogenerator.
LVAD
A left ventricular assist device (LVAD) is a pump that we
use for patients who have reached end-stage heart
failure.
LVAD is a battery-operated, mechanical pump, which
then helps the left ventricle (main pumping chamber of
the heart) pump blood to the rest of the body.
Other Applications
Nanogenerator can be embedded in clothing for making
smart wearables.
Soon Nanogenerator might be able to power our
electronic devices like mobile phone, I-pod, tablets etc.
It is highly desired for wireless devices like sensors etc.
It can be also easily integrated in the shoe employing the
walking motion of human body.
Limitations
Complex manufacturing process.
Efficiency is not very high.
The impact is small due to the size and limited power of
Nanogenerator.
Cannot power devices which are not in regular physical
contact, such as alarm clocks.
Performance effected by environmental conditions.
Devices is strong enough to endure long-time exposure
to the vibration motion.
Packaging material has to be provide to protect the
device.
Future Research
BaTiO3 is replacing Zno in nanowire fabrication as shows better piezoelectric effect.
Integration of Nanodevice into a Nanosystem with capabilities of sensing, controlling, communicating and responding.
Hybrid Nanogenerator are being developed (To harvest both solar and mechanical energy).
Researchers in Korea have recently developed a new manufacturing technique which will improve the efficiency drastically.
In near future this mode of electricity production will prove to be highly promising.