A

REPORT

ON

SOUND ENERGY AND ELECTRICITY

BY

ADRITA MAJUMDER, ECE1 08

A REPORT SUBMITTED IN PARTIAL FULLFILLMENT OF THE

REQUIREMENTS OF

HU481: TECHNICAL REPORT WRITING

13TH MARCH 2014-02-27

ACADEMY OF TECHNOLOGY

AEDCONAGAR, HOOGHLY- 712121

CERTIFICATE BY THE SUPERVISORS S.CHATTERJEE

Assistant Professor, Department of Engineering Science and Humanities,

Academy Of Technology, Adisaptagram

S.CHATTERJEE

Assistant professor, department f engineering science and humanities

Academy of technology, Adisaptagram

This is to certify that technical report entitled sound energy and electricity is a document of

work done by Adrita Majumder under our supervision during the period January 2014 to

march 2014

...........................................

S.CHATTERJEE

............................................

S.CHATTERJEE

STATEMENT BY THE CANDIDATEAdrita Majumder

B.Tech 4th Semester

Department of ECE, Roll Number 08

Academy Of Technology

I hereby state that the technical presentation entitled sound energy and electricity has been

prepared by me to fulfill the requirement of HU481 during the period January 2014 to March

2014.

ACKNOWLEDGEMENTI would really like to thank every person who has helped to complete my report successfully.

All the websites where I have taken help from. All my friends who have helped to chose this

topic and collect every bit of information about the topics. A special thanks to my best friend

Rajarshi without whom completion of this very report would have been just impossible.

Definitely my parents and my professors are worth mentioning who have kept supporting me

throughout and have kept faith that I could do it.

ABSTRACTWe all are well aware of the crisis of electricity that we, the present generations are facing. If

we can ‘non -technically’ define what sound energy is, we would say it is the most neglected

form of energy which is only considered to be a wastage. But the actual scenario is a bit

different. Since the population explosion the consumption of food, space has increased. So

has increased the consumption of electrical energy. But as we all are well known to the

theorem of energy conservation- Energy can neither be created nor be destroyed, it can be

converted from one form to another. So here we change the energy which is commonly

available – sound to the energy which our world is scarce of – electricity.

Since we are actually talking about the conversion of a form of energy to the other, we must

remember that the conversion of energy is in accordance with the law of conservation of

energy – energy can neither be created nor be destroyed, it can be changed from one form to

the other. Chapter 1 deals with the various devices like piezoelectric crystal transducer, sonea

converts the sound energy to electrical energy. their exact structure and function has been

clearly defined. Chapter 2 deals with the acoustic sound harvesting that is the way by which

sound converted to electricity can be stored and utilised in future. Chapter 3 gives us a real

life experiment where sound energy was harvested in London and from that harvested sound

electricity was generated. In chapter 4 the various applications of this conversion of sound

energy to electrical energy has been discussed. How the various application of this technique

will make our life-style easier is seriously dealt with. Chapter 5 talks about the merits and

demerits of using this conversion technology.

Finally we conclude that after population explosion, since the consumption of electricity has

been increasing, there is an utter lack in the resources which produce electricity. So sound

energy conversion to electricity is one of the best measures that can give the permanent

solution to the lack of electricity, in this generation.

LIST OF FIGURES

Fig 1.1 Is It Possible To Convert Sound Energy To Electricity

Fig 2.1 Piezoelectric Crystal

Fig 2.2 SONEA

Fig 4.1 The Power Of Footfall Being Harvested In London Olympic Games

Fig 5.1 Sound Conversion Into Electromagnetic Energy

Fig 5.2 Transducer Chip In Human Heart

Fig 5.3 Piezo Electric Crystal Transducer

Fig 7.1 Schematic Representation Of Energy Conversions

TABLE OF CONTENTSTITLE PAGE NUMBER

Certificate by the supervisors i

Statement by candidate ii

Acknowledgement iii

Abstract iv

List of figures v

Introduction 1

Devices that convert sound energy to electricity 2

Acoustic sound harvesting 4

Harvesting the power of footfall 5

Applications 6

Advantages and disadvantages of the conversion technique 8

Conclusion 9

Bibliography 10

INTRODUCTIONConverting sound into electricity works on a simple mechanism. If heat is applied to any

enclosed area, the air inside it expands increasing the pressure inside. This pressurized air,

then moves through a filter or opening on one side, producing a simple clear sound at a

standard frequency. That is the basic idea behind the system. Focused and directed frequency

makes it easier to extract energy.

Well, not quite, however good old-fashioned sound just might do the trick thanks to the work

by University of Utah Physicist Orest Symko and his students who have developed a way

to turn excess heat into sound and electricity. If it sounds too good to be true, well then you

might be surprised to hear that it actually works! It works via a very simple and well known

process. If you take a source of heat and apply to any enclosed area, the air inside it will

expand increasing the pressure inside. This pressurized air will then move through a filter or

opening on one side, producing a simple clear sound at a standard frequency. That’s the key

to the system. The more focused and directed the frequency is, the easier it is to extract energy

from.

We all know sound energy is a mechanical energy which travels in the form of wave.

Longitudinal waves are of alternating pressure deviation from the equilibrium pressure,

causing local region of compression and rarefaction, while transverse wave (in solid) are

waves of alternating shear and stress at right angle to the direction of propagation. When

sound wave travel through a medium mater in that medium is periodically displaced and thus

oscillates with sound wave. The sound wave displace back and forth between the potential

energy of compression or lateral displacement strain of the matter and the kinetic energy of

the oscillation. As sound energy is a mechanical energy it could be converted into electricity

as mechanical energy could be converted into electricity by the law of thermodynamics.

FIG 1.1 IS IT POSSIBLE TO CONVERT SOUND ENERGY TO ELECTRICITY?

DEVICES THAT CONVERT SOUND ENERGY TO ELECTRICITYPiezoelectric are materials capable of turning mechanical energy into electricity, and can be

substances as simple as cane sugar, bones, or quartz. Much research in this field has been

focused on transforming the movement of a person running, or even the impact of a bullet,

into a small electrical current, but although these advanced applications are not yet available

in consumer products, scientists have been using piezoelectric materials in environmental

sensors and speakers for years.

FIG 2.1 PIEZOELECTRIC CRYSTAL

The Korean researchers were interested in reversing this process however. "Just as speakers

transform electric signals into sound, the opposite process - of turning sound into a source of

electrical power - is possible," said Young Jun Park and Sang-Woo Kim, authors of the article

in journal Advanced Materials.

Piezoelectric create an electrical charge under stress, and thus zinc oxide, the main ingredient

of calamine lotion, was bent into a field of nano wires sandwiched between two electrodes.

The researchers subjected the sandwich to sound waves of 100 decibels which produced an

electrical current of about 50 milli-volts.

FIG 2.2 SONEA

Sonea are devices which can convert sound energy to electricity. This a bit different from the

other devices because this not only converts sound energy to electricity but also that it has a

cell which can store the electricity for future use. Not always do we need the entire electricity

created so it is sometimes necessary to store the energy so that it can be used whenever we are

lacking electricity.

ACOUSTIC SOUND HARVESTING

Acoustic energy is generated and unused all around us. Whether it is the constant hum of an

HVAC unit behind a building, an airplane taking off at the airport or a train departing the

station, acoustic energy is cast off as a nuisance or ear sore. Most of these locations try to

absorb as much of this energy as possible or are in remote locations so that their customers do

not have to be susceptible to the high amount of noise. But with the large focus on 'green

energy' as of late, efficiency and harnessing all possible forms of energy has come to the

forefront and the loss of any type of energy has become a sin.

Acoustic energy harvesting is the process by which energy is derived from external noise

sources, captured, stored, and controlled for small wireless autonomous devices. Acoustic

energy harvesting is not as popular as the other types of energy harvesting method since

sound waves have lower power density. However, in this age of efficiency and alternative

energy sources research, acoustic energy harvesting has become something that can't be

overlooked since it is one of the vastly available energy sources. From the initial stages of this

project, we have managed to finish up the final draft for the product design. During these

phases, the goal was to develop the specifications for a small device that could harness energy

from ambient noise and convert it into usable electrical energy. The main focus during this

portion of the project was on technical research, theoretical calculation, and data acquisition

in order to determine the best combination that yielded the best results.

AOUSTIC ENERGY HARVESTING DEVICE

The device was model based on the Side Branch Helmholtz Resonator, which consists of a

neck, cavity chamber, and membrane attached at the end of the chamber. The membrane is

connected to piezoelectric material that converts the vibrations caused by the sound into

electrical energy. This energy will then be directed to a storage device that will be capable to

autonomously stored. As for the storage device, we will be using CYMBET CBC EVAL 09

Ener Chip CP, an energy harvesting evaluation board that can track and measured the energy

generation while at the same time having the ability to store and channelled the collected

energy.

HARNESSING THE POWER OF FOOTFALLEndless amounts have been written about what is the right path to a low-carbon future – but

not much of that commentary has focused on the role that literal paths could play. Yet in the

future we may all be generating energy wherever we go, whether we're walking, driving or

sitting on the train, using a technique known as energy-harvesting.

There are two main approaches. One is to use mechanical technology to capture the energy

and convert it into electricity and the other is to use piezoelectric materials, which produce

electricity when they are put under pressure – when someone steps on them or drives over

them, for example. One of the best-known uses of the technique was in a club in Rotterdam,

which installed an energy-generating dance floor, where the dancers created their own light

show. While in the UK, a company, Pavegen, has generated energy from schoolchildren

running to their next lesson, from thousands of runners at this year's Paris Marathon, revellers

at the Bestival music festival on the Isle of Wight and spectators travelling to watch the

London 2012 Olympic Games via West Ham tube station. The technology is ideal for

anywhere that attracts crowds, so ticket barriers at train and tube stations are an obvious

application, but the concept will also work at shopping centres, sports venues, even airport

terminals. And as a technique that produces more energy when more people travel across the

energy-producing materials, it's a particularly elegant solution to matching supply with

demand. As well as harnessing the power of pedestrians, energy harvesting also works well in

roads and on rails. Innowattech, has been conducting tests on embedding piezo-materials into

roads and railways to generate energy as vehicles pass over them, which is then stored in

batteries which can be used to power roadside lights or feed into the grid.

FIG 4.1 THE POWER OF FOOTFALL BEING HARVESTED IN LONDON OLYMPIC

GAMES

APPLICATIONS Researchers in Japan and Germany have converted energy from sound waves into

electromagnetic energy, trapping a magnetic "spin current" between metal layers. In the

experiment, when sound waves are directed at an interface between the thin metal layer and

magnetic material, electrical signals are generated at a pair of electrodes attached above.

When the sound waves reach the magnetic material, this creates a spin current that gets picked

up by three layers of metal. This is where the exercise class-sounding reverse spin Hall effect

kicks in, transforming it into an electrical voltage.

FIG 5.1 SOUND CONVERSION INTO ELECTROMAGNETIC ENERGY

Recent exeperimentations have come to a conclusion that our own heart beat can chanrge our

phone. An experiment was performed in Russia where a transducr chip was surgically

implemented in the heart of a human being. The lubb and dupp sounds of the heart creates

sonic vibrations which by external circuitry can charge a phone.

FIG 5.2 TRANSDUCER CHIP IN HUMAN HEART

Not only this, but also a phone with a piezo electric crystal transducer can convert sound

energy into electricity and charge a phone. A piezo electric crystal transducer delivers electric

power by converting sonic waves into electricity and hence it can charge a phone. So

basically talking over th mobile phone charges it.

FIG 5.3 PIEZO ELECTRIC CRYSTAL TRANSDUCER

ADVANTAGES AND DISADVANTAGES OF CONVERSION OF SOUND

TO ELECTRICITY

MERITS

As sound has enormous amount energy with it, it could be used by converting it into

electric energy for various purposes

Sound energy is a mechanical energy so according to law of thermodynamics

mechanical energy could be converted into electric energy

Sound energy could be converted by different methods by creating apparatus using

curtain (diaphragm) magnet and conductor ,by converting Sound energy to heat

energy and then heat energy to electric energy ,by using transducers such as

piezoelectric material which converts mechanical strain to electric energy and vice4

versa

Piezoelectric crystals are the crystals which converts mechanical strain to electric

energy

The strain applied to piezoelectric material by sound energy could be converted into

electricity

In this aspect lot of research is to be done but on a positive note this could surely be

done which could solve the energy problem of the entire world

DEMERITS

Lots of work is to be done in this field.

Its efficiency is not that good so improvement is being required.

It is bit costlier as a whole setup would be done.

It could not be used in the places where decibel of sound is very low.

CONCLUSIONResearcher Dr. Sang-Woo Kim said, "The sound that always exists in our everyday life and

environments has been overlooked as a source. This motivated us to realise power generation

by turning sound energy from speech, music or noise into electrical power. Currently, the

researchers have created a prototype that converts sounds around 100 decibels (think: noisy

traffic) to 50 milli-volts of electricity. Here's how it works: a pad absorbs sound waves and

causes zinc oxide wires mounted between electrodes to compress and release, creating an

electrical current that can be used to charge a battery. Fifty milli-volts isn't enough to charge a

mobile phone, but Dr. Kim said that the technology could be improved by using different

materials. Fortunately, the current prototypes create enough energy to be usable in small, low-

power sensors and implantable devices

FIG 7.1 SCHEMATIC REPRESENTATION OF ENERGY CONVERSIONS

If we will be able to convert sound energy to electric energy efficiently it could help us to

reduce the scarcity of electrical energy globally and help in the development of mankind and

reduction of CO2 as electric energy is one of the cleanest energy. The noise pollution in the

road would be able to convert into electric energy and lights the street lighting, signals and

various other electrical appliances. The noise pollution in runway could be used to produce

electricity. The electricity produce in nuclear power station could increase as the sound

produce during nuclear fission also could be used to get more electric energy. The noise

pollution in industries could be used to produce electricity and work certain low voltage

machine its scope doesn’t end.

BIBLIOGRAPHY

[1] “Piezoelectricity”, Wikipedia, The Free Encyclopedia, Wikimedia foundation, 2006,

http://en.wikipedia.org/wiki/Piezoelectricity, 24/01/2014.

[2] “Transducer”, Wikipedia, The Free Encyclopedia, Wikimedia foundation, 2006,

http://en.wikipedia.org/wiki/Transducer, 24/01/2014.

[3]“Sonea”,http://www.yankodesign.com/2009/09/09/sonea-converts-sound-to-energy/,

26/02/2014.’

[4] “Researchers convert soundwaves into electromagnetic energy, silence no longer golden’’ ,

http://www.engadget.com/2011/09/20/researchers-convert-soundwaves-into-electromagnetic-

energy-sile/, 28/02/2014.