An electronic nose, or e-nose, is an instrument that mimics the human olfactory system and is designed to identify and classify chemical vapors. It consists of three main parts: a sample delivery system, a detection system with an array of different gas sensors, and a computing system. When a vapor sample is introduced, the sensors produce an electrical response that is sent to the computing system for analysis. E-noses can be used in applications like medical diagnosis, environmental monitoring, food quality control, and more. They provide a cheap and fast alternative to traditional analytical techniques.

1. Presented by:
SONU YADAV
EC 3rd YEAR
ROLL NO.123633096

2. CONTENTS
• Introduction(e-nose), e-sensing,
• Definition: electronic nose(e-nose),Basic design of an e-nose
• Comparison of e-nose with biological nose
• The need of an e-nose
• The e-nose---An overview
• Working principle of an e-nose
• Sensor technology in e-nose
• Performing an analysis with an e-nose
• Applications of e-nose
• Conclusion

3. Introduction-electronic nose
(e-nose)
o Electronic noses are engineered to
mimic the mammalian olfactory system.
o Instrument designed to allow
repeatable identifications and
classifications of aroma mixtures.
 e-sensing
Refers to the capability of reproducing human senses using sensor arrays
and pattern recognition systems.

4. Definition: electronic nose
(e-nose)
• Device intended to detect odors 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.

5.  Fig: Basic design of an e-nose

6. Biological Nose E-Nose
Inhaling Pump
Mucus Filter
Binding with proteins Interaction
Enzymatic proteins Reaction
Cell membrane depolarized Signal
Nerve impulses Circuitry and neural network
• Each and every part of the electronic nose is similar to human
nose.
• Comparison Table:
Comparison of e-nose with biological nose

7. • 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.
• There lies a great chances of difference in the values got by each
individual.
The need of an e-nose

8.  The e-nose---An overview
o An air sample is pulled by a vacuum pump.
o It is led through a tube into a small chamber consisting of electronic
sensor array.
o A transient response is produced as the volatile organic compounds in the
sample interact with the surface of the sensor’s active material.
o A steady state response is reached within few minutes.
o This response is then sent to a signal processing unit.

9. Electronic noses include three major parts:
I. a sample delivery system
II. a detection system
III. a computing system
I. Sample delivery system
o Enables the generation of the
headspace (volatile compounds)
of a sample.
o The system then injects this
headspace into the detection
system of the e-nose.
Working principle of an e-nose

10. • Consists of a sensor set, is the "reactive" part of the instrument.
• Adsorption 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.
III. Computingsystem
o Works to combine the responses of all
of the sensors.
II. Detection system

11. (1) Conductivity sensors
Metal oxide sensors(MOS) Conducting polymers
(2) Piezoelectric sensors
(3) MOSFET sensors
(4) Optical sensors
Sensor technology in e-nose
o The sensor array is clearly the key element. It forms the primary step in
the detection or identification of an odorant.
o The most commonly used sensor s in electronic nose are:

12. 1a- MOS (Metal oxide sensors) -
o Adsorption of gas molecules provoke changes in conductivity .
o This conductivity change is the measure of the amount of volatile organic
compounds adsorbed.
o Conducting or conductive polymer gas sensors operate based on changes
in electrical resistance caused by adsorption of gases onto the sensor
surface.
(2) Piezoelectric sensors-
• Adsorption of gas onto the surface of the polymer leads to change
in mass on the sensor surface.
• This in turn produces a change in the resonant frequency of the
crystal.
• This change in frequency is proportional to the concentration of
the test material.
(1b) Conducting polymers-

13. (3) MOSFET (Metal Oxide Silicon Field Effect Transistor )sensors-
o A volatile organic compound
produces a reaction in the sensing
layer(gate).
o This causes the physical property
of the gate to change.
o Thereby the threshold voltage is
changed and thus the channel
conductivity.

14. (4) Optical sensors-
o Optical sensor systems are somewhat more complex than typical sensor-
array systems having transduction mechanisms based on changes in
electrical resistance.
o Optical sensors work by means of light modulation measurements.
 Performing an analysis with an e-nose
o As a first step, an e-nose needs to be trained with qualified samples so
as to build a database of reference.
o Then the instrument can recognize new samples by comparing volatile
compounds fingerprint to those contained in its database.
o Thus they can perform the analysis.

15. Applications of E-nose
The applications(current) of an electronic nose
include:
o Medical diagnosis and health monitoring
o Environmental monitoring
o Application in food industry
o Detection of explosives
o Space applications(NASA)
o In research and development industries
o In quality control laboratories
o In process and production department

16. Medical diagnosis and health monitoring by e-nose
I. Respiratory disease diagnosis-
o Human breath contains thousands of volatile organic compounds (VOCs)
in gas phase.
o E-nose can diagnose respiratory infections such as pneumonia.
o It does so by comparing smell prints from the breath of a sick patient with
those of patients with standardized readings.
o It is also being studied as a diagnostic tool for lung cancer.
II. Urinary Tract infections-
o The e-nose as a potential diagnostic tool for patients affected with
kidney diseases, by distinguishing traces of blood in urine samples.

17. o E-nose is capable of distinguishing between
the breath of a healthy person and a person
with cancer.
o The device is especially promising because it
is able to detect cancer before tumors
become visible in X-rays.
 Environmental monitoring by e-nose
o Environmental applications of electronic noses include:
(1) analysis of fuel mixtures
(2)detection of oil leaks
(3) testing ground water for odours
(4)identification of household odours
(5)identification of toxic wastes
(6)air quality monitoring
(7)monitoring factory emissions etc.
III. Cancer detection-

18. Applications of e-nose in food industry
Analysis of fruit ripening-
o Fruit ripening is associated with an
accumulation of aromatic volatiles during
ripening.
o Information from the noses can help in
removal of rotten fruits at the appropriate
time.
o This can help in avoiding storage losses due
to rots and fruit diseases.
 Detection of explosives
o E-nose is being developed for military and
security applications in the detection of
explosives and hazardous chemicals.

19. JPL Electronic Nose (e-nose)-A Brief Summary:
o It is a full-time, continuously operating event
monitor used in the International Space
Station.
o Designed to detect air contamination from
spills and leaks in the crew habitat
o Provides rapid, early identification and
quantification of atmospheric changes
caused by chemical species to which it has
been trained.
o Can also be used to monitor cleanup
processes after a leak or a spill.
Space applications---e-nose and NASA

20. Conclusion
o An “electronic nose” is a system originally created to mimic the function
of an animal nose.
o Offers a cheap and non destructive instrument that (if properly
programmed and automated) can be operated by non specialists.
o Since the whole process is automatic, the cost of each measurement is
very low.
o Finally, the measurement cycle should be faster in order to increase
throughput.
o However, this analytical instrument is more a “multi-sensor array
technology” than a real “nose”.
o Therefore, its aim is not to totally replace either the human nose or
other analytical methods.

21. REFERENCES
o www.wikipedia.org
o www.slideshare.com
o www.powershow.com
o www.google.com

22. Thank you..