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.