N0ISE…

IS IT ENERGY??..

IDEATE-UJJWAL.

Parth RanaArch DesaiVidit Dave

TOPIC:

How can we utilize

sound energy for

useful purposes?

NEED:Currently we are on the verge

of exhausting all the fossil fuel

reserves we have. In these

circumstances alternatives are

to be looked at. One such

alternative is also sound, which

is omnipresent.

PRINCIPLE:

Sound creates pressure

waves. These pressure

wave are capable of doing

mechanical work, thus this

mechanical energy is

where our focus lies.

THIS DIAGRAM SHOWS HOW SOUND

WAVE TRAVERSE IN ANY MEDIUM BY

COMPRESSION AND RAREFRACTION.

AND THIS IS THE FORM OF ENERGY.

OUR DEMONSTRATION:

We have constructed a series microphone system. This system consists of a metal plate, moved by the pressure exerted by sound waves. The coils attached at the back of the plate, under the effect of pressure conduct induced current, generated by change in flux under magnetic field.

On connecting the series of these coils, we can generate current.

C.R.O. Readings of a typical

microphone.(Courtesy: Clifton Laboratories)

The oscilloscope readings shown before

are taken when it was spoken as loudly as

would be comfortable for a short duration.

The peak-to-peak voltage is 140 mV.

Circuit arrangement for rectification of the electrical output.

LIMITATIONS:

Will require highly advance technology to

manufacture the sheets we have discussed

about.

Large system. 100 sq. feet area generates

only about 50 volts.

Very high and constant noise intensity

required for proper functioning.

The output at load is very low also because of

the power dissipation at the circuit elements.

FUTURE PROSPECTS:

The system is capable of producing about 0.5

microamperes and 5 millivolt, thus optimizing

the size of such coils and magnets, using

industrial production; just the way transistors

were developed after the miniaturization of

vacuum tube, long sheets with hundreds of

such components can be connected and

placed in public area where the intensity of

noise is very high, for example the traffic

signals, railway platforms etc.

Also rectification of the output waves can

be done to eliminate the reverse currents

due to negative fluxes. If we just estimate

the output, considering future

technologies and assuming cluster of

about 100,000 such coils in a 100 sq. feet

surface area sheet, we can get an output

of about 50 volts, which can run single ELV

LED traffic light!

Future work of the proposed idea encompasses

further amplification of the crystal

output to a greater extent. Future lies in the

inclusion of advanced material used to design

the piezoelectric crystal which further amplifies

the crystal output in terms of voltage as

well as current. A study could be carried out

from the variety of piezoelectric crystals and

after comparing the results, the choice of the

optimum material for the best performing crystal

could be devised

Piezoelectric Component

This is Piezoelectric Component , in which there are two axis mechanical & electrical, if we give pressure along mechanical axis because of the molecular structure the the electrons gather one side of electrical axis and the p.d. will be generated.

Why Piezo?

Using piezoelectric crystal in place of coil, we can get better results. Using modified diaphragm, we can utilize the pressure in efficient way.

Typical piezoelectric transducer prodcucesabout 0.15mA across 10kΩat 25 Hz frequency.

Charging of NOKIA Lumia 925

using ZnO Piezo:

Courtesy: Queen Mary University of London (QMUL)

Research paper published on 10th july,2014

Zinc Oxide can be made into nanorods or nanowires, which can be coated onto almost any surface. When this surface is squashed or bent, the nanorods then generate a high voltage. This means they respond to vibration and movement created by everyday sound e.g. our voices. If you then put electrical contacts on both sides of the rods you can use the voltage they generate to charge a phone.

In order to make it possible to produce these nanogenerators at scale, the team developed a process whereby they could spray on the nanorod chemicals – almost like nanorod graffiti – to cover a plastic sheet in a layer of Zinc Oxide. When put into a mixture of chemicals and heated to just 90 °C, the nanorods grew all over the surface of the sheet.

This experiment was performed in controlled conditions so it has some

limitations. so we cant use it for mass production.

That can be improved using MEMS technology .

Generation by Piezoelectric

Crystal using MEMS

technology: Microelectromechanical systems (MEMS): is the technology

of very small devices; it merges at the Nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology.

Piezoelectric materials, which turn produce electric charge when pressure is applied to its ends is a very useful tool for generation of electricity using low intensity vibrations.

With the development in fabrication methods, it has become possible to fabricate micro level systems, sensitive to the vibrations and provide electrical output using piezoelectric crystals.

One such micro system, consisting of PZT-5A crystal and cantilever system is one of the many researched ways to utilize sound vibrations and generate output from it.

The piezoelectric crystal and cantelever

are arranged (A) as shown in the figure:

Here, results at various sound intensities and

resonant frequencies are as follows (B) :

Distance

(cm)

Resonant

Frequency(Hz)

Sound

Intensity(dB)

Output

Voltage(mVrms)

1 62 78.6 26.7

3 62 75.6 13.3

5 69 74.0 8.7

From one particular reference (C), further information regarding the outputs from such systems are obtained:

"For the development of the MEMS devices, Jeonet al. (D) have successfully developed the firs MEMS based micro-scale power generator using d33 mode of PZT material. A 170μm × 260μm PZT beam has been fabricated. A maximum output power of 1.01μW across the load of 5.2MΩ at its resonance frequency of 13.9 kHz has been observed. The corresponding energy density is 0.74mWh/cm2, which compares favorably to the values of lithium ion batteries.

Fang et al. (E) successfully developed a PZT MEMS power-generating device based onthe d31 mode of piezoelectric transducers that uses top and bottom laminated electrodes. ThePiezoelectric MEMS Power Generators for Vibration Energy Harvesting 139 cantilever size is of 12μm thick silicon layer, 2000μm × 500μm cantilever in length and width 500μm × 500μm metal mass (length × height), which generated 1.15μW of effective power when connected to a 20.4kΩ resistance load, leading to a 432mV ac voltage. An improved device was announced later that under the 608Hz resonant frequency, the device generated about 0.89V AC peak–peak voltage output to overcome germanium diode rectifier toward energy storage. The power output obtained was of 2.16μW. “

However, the sound intensities are too high while dealing with this experiment, but with improvement in manufacturing technologies, more sensitive generators can be produces.

MEMS Industry will become $22 Billion market by 2018 and constant research continues in this field.

Hence, Micro generators may turn out to be a complete replacement of the mechanical generators we have made.

REFERENCES:

(A),(B): Acoustic Energy Harvesting Using Piezoelectric Generator for Low Frequency Sound Waves Energy Conversion: Haris Fazilah Hassan , Syed Idris Syed Hassan, Rosemizi Abd Rahim International Journal of Engineering and Technology

(C):Piezoelectric MEMS Power Generators for Vibration Energy Harvesting-Wen Jong Wu and Bor Shiun Lee

(D):Y. B. Jeon, R. Sood, J. H. Jeong and S. G. Kim. MEMS power generator with transversemode thin film PZT. Sensors and Actuators a-Physical. 2005

(E): H. B. Fang, J. Q. Liu, Z. Y. Xu, L. Dong, D. Chen, B. C. Cai and Y. Liu. A MEMS-based piezoelectric power generator for low frequency vibration energy harvesting. Chinese Physics Letters. 2006

H. B. Fang, J. Q. Liu, Z. Y. Xu, L. Dong, L. Wang, D. Chen, B. C. Cai and Y. Liu. Fabrication and performance of MEMS-based piezoelectric power generator for vibration energy harvesting. Microelectronics Journal. 2006

If, in future, this technology

is put into such

applications,

Noise will not be a source

of pollution, but an energy!

Thank You!