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Under Guidance Of: PRESENTED BY:Dr SHAHANAZ AYUB 130433901(Associate Professor) (Electronics and Comm. Engg.)Deptt. Of Electronics and Comm. Engg. 3rd Year BIET JHANSI BIET JHANSI

E-NOSE

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Content Introduction

Definition and explanation

History

Need of an e-nose

Working principle

Sensor technology in e-nose

Performing an analysis with an e-nose

Applications

Conclusion

References

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Electronic noses are engineered to mimic the mammalian olfactory system.

Instrument designed to allow repeatable identifications and classifications of aroma

mixtures.

Determines the various characteristics properties of the odour while eliminating

operator fatigue.

Introduction- electronic nose(e-nose)

e-sensing

Refers to the capability of reproducing human senses using sensor arrays and

pattern recognition systems.

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Definition: electronic nose(e-nose)

Device intended to detect odour or flavors.

Can be seen as arrays of sensors able to generate

electrical signals in response to either simple or

complex volatile compounds present in the

gaseous sample.

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The first electronic noses were reported by Wilkens and Hatman in 1964

including Redox reactions.

The term electronic nose appeared around 1980s.

IN 1989, At conference of NATO chemo sensory information processing was

detected.

Finally first conference dedicated to e-nose was held in 1990.

History of e-nose

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The human sniffers are costly when compared to electronic nose.

Speedy, reliable new technology of the gas sensors are used in the electronic

nose

Detection of hazardous or poisonous gas is not possible with a human sniffer.

An e-nose also overcomes other problems associated with the human

olfactory system.

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Need of an e-nose

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Electronic noses include three major parts:

i. a sample delivery system

ii. a detection system

iii. a computing system

Working Principle

Sample delivery system

Enables the generation of the headspace (volatile compounds) of a

sample.

The system then injects this headspace into the detection system

of the e-nose.

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Detection System

Consist of a sensor set, is the "reactive" part of the instrument.

Absorption of volatile compounds on the sensor surface causes a physical change of the

sensor, they experience a change of electrical properties.

A specific response is recorded by the electronic interface transforming the signal into a

digital value.

Recorded data are then computed based on statistical models.

Computing System

Works to combine the responses of all the sensors.

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Metal oxide sensors

Adsorption of gas molecules provoke changes in conductivity.

This conductivity change is the measure of the amount of

volatile organic compounds adsorbed.

Conducting polymers

Conducting or conductive polymer gas sensors operate based on

changes in electrical resistance caused by adsorption of gases on

sensor surface.

Sensor technology in E-nose

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Quartz crystal microbalance

It’s a way of measuring mass per unit area by measuring the change

in frequency.

Can be stored in data base for future references.

Surface acoustic wave

It depends on modulation of surface acoustic wave to sense a

physical phenomenon

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Performing an analysis with an e-nose

As a first step, an e-nose needs to be trained with qualified samples so as to build a database

of reference.

Then the instrument can recognize new samples by comparing volatile compounds

fingerprint to those contained in its database.

Thus they can perform the analysis.

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Medical diagnosis and health monitoring

Environmental monitoring

Application in food industry

Detection of explosives

Space applications(NASA)

In research and development industries

In quality control laboratories

In process and production department

APPLICATIONS OF ELECTRONIC NOSE

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An “electronic nose” is a system originally created to copy the function of an animal nose.

Since the whole process is automatic, the cost of each measurement is very low.

Finally, the measurement cycle should be faster in order to increase throughput.

This sensor technology is still far from the sensitivity and selectivity of a real nose.

So it can’t totally replace the nose but can be used for different purposes with better

advancement in technology in future.

Conclusion

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[1] J.W. Gardner, P.N. Bartlett, "A brief history of electronic noses", Sensors and Actuators B, Vol.

18, 1994, pp. 211-220.

[2] Baltes, D. Lange and A. Koll, The electronic nose in Lilliput. IEEE Spectrum35 9 (1998), pp.

35-38.

[3] http://en.wikipedia.org/wiki/electronic nose

[4] I. Lundstrom, A. Spetz, F. Winquist, U. Ackelid, H. Sundgren, "Catalytic metals and field-effect

devices-a useful combination", Sensors and Actuators B: Chemical, Volume 1, Issues 1-6,

January 1990, Pages 15-20.

References

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Thank you