What is e–sensing?
Major parts of e- nose
Analogy between e-nose and human nose
Development of e-nose
Example of e-nose
Electronic noses are engineered to mimic
the mammalian olfactory system.
It is an array of non-specific chemical
The sensors used here are conduct metric
chemical sensors which change resistance
when exposed to vapours.
Gases and gas mixtures can be identified
by the pattern of response of the array.
What is e-sensing ?
Electronic Sensing” refers to the capability of
reproducing human senses using sensor arrays and
pattern recognition systems.
The three major parts of
I. A sample delivery system.
II. A detection system
III. A computing system.
1.Sample delivery system
Enables generation of a
sample which is to be
Then it is injected to
2.The detection system
Contains a group of sensors to sense the
Sensors react to the compound and the response
is recorded by an electronic interface.
Transforms signal into digital value
3.The computing system
It combines the responses of all sensors to
produce a result.
These results can be easily analyzed with
a database of qualified samples.
New samples are identified by comparing
those with the samples in database.
DEVELOPMENT OF E - NOSE
Second Generation ENose
Third Generation ENose
FIRST GENERATION E
The first generation of e-nose
were based on Sensor Arrays
(with different types of
The 1st generation E Nose
Sensor Unit flight
experiment, which flew aboard
the STS-95 (1998), used an
HP-200LX Palmtop Computer
for device control and data
data were collected and
analyzed after landing.
SECOND GENERATION E
The second-generation E
Nose has the same
functions as the firstgeneration device, but has
been miniaturized to occupy
less than 1000 cm3 with a
mass ~800 g, not including
the operating computer.
The sensors are films of
polymers which have been
loaded with carbon to make
THIRD GENERATION E NOSE
It includes an ISS interface
unit, which conforms to
telemetry, display and data
storage requirements for ISS.
The E Nose Sensor Unit
consists of an anodized
aluminium chassis which
houses the Sensor array and
The Cyranose 320 is a handheld “electronic nose”
developed by Cyrano Sciences of
Pasadena, California in 2000.
The Cyranose 320 is based on sensor research
performed by Professor Nathan Lewis of the
California Institute of Technology.
Applications researched using the Cyranose 320
include the detection of COPD, and other medical
conditions as well as industrial applications
generally related to quality control
Applications(current) of an electronic nose
Medical diagnosis and health monitoring
Application in food industry
Detection of explosives
In research and development industries
In quality control laboratories
In process and production department
The possible and future applications of
an electronic nose include:
Detection of drug odors etc.
In field of crime prevention and security
Detection of harmful bacteria
Medical diagnosis and health
monitoring by e-nose
I. Respiratory disease diagnosis Human breath contains thousands of volatile organic
compounds (VOCs) in gas phase.
E-nose can diagnose respiratory infections such as
It does so by comparing smell prints from the breath of a
sick patient with those of patients with standardized
It is also being studied as a diagnostic tool for lung
II. Cancer detection E-nose is capable of distinguishing
between the breath of a healthy
person and a person with cancer.
The device is especially promising
because it is able to detect cancer
before tumors become visible in Xrays.
Environmental applications of
electronic noses include:
analysis of fuel mixtures
detection of oil leaks
testing ground water for odours
identification of household odours
identification of toxic wastes
air quality monitoring
monitoring factory emissions etc.
Applications of e-nose in food industry
Analysis of fruit ripening Fruit ripening is associated with an
accumulation of aromatic volatiles
Information from the noses can help in
removal of rotten fruits at the
This can help in avoiding storage losses
due to rots and fruit diseases.
In the field crime prevention
E-nose is being developed for military and security
applications in the detection of explosives and
to detect drug odours despite other airborne odours
capable of confusing police dogs
Space applications---e-nose and
It is a full-time, continuously
operating event monitor used in the
International Space Station.
Designed to detect air contamination
from spills and leaks in the crew
Provides rapid, early identification
and quantification of atmospheric
changes caused by chemical species
to which it has been trained.
An “electronic nose” is a system originally created to mimic the
function of an animal nose.
Offers a cheap and non destructive instrument that (if properly
programmed and automated) can be operated by non specialists.
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
However, this analytical instrument is more a “multi-sensor array
technology” than a real “nose”.
Whatever the sensor technology, it is still far from the sensitivity and
selectivity of a mammalian nose.
Therefore, its aim is not to totally replace either the human nose or
other analytical methods.