Smell Electronically!

Now days we see electronics in almost all the fields of human life science making human life more comfortable, which works more intelligently as compared to human being. In many fields electronics had proven its better performance and quality than human counterparts like making calculations, vision, speed of processing, decision making etc. This article will brief the advancements and some latest news related to smelling electronically.

The human nose is the base for the identifying the smell, that might of food, perfumes etc from years. But there are certain limitations beyond which a human being can’t smell good. The circumstances like common cold, winter or rainy environment or some natural limitations are there beyond which a person can not smell correctly. Dogs or other living animals are having better accuracy of identifying the odors rightly.
The electronic smelling had gone much more beyond that in terms of accuracy. It automatically detects and recognizes odors.

Construction:
The E-Nose has chemical sensing system and a pattern recognition system. It consists of an array of chemical sensors. This array’s each element measures different property of the sensed chemical compound. It may be a spectrometer. This will also produce an array of measurements for each chemical. There may be combination of both of them. Each chemical vapor has a signature or pattern characteristic of the vapor. We present many different chemicals to the sensor array and create a database of signatures. Now this database will used to train the pattern recognition system. The aim of the training is to configure the recognition system which will give unique classification.

We need number of sensors at least equal to number of chemicals being monitored. Here for identifying chemical we use an array of sensors and each sensor responds to a specific chemical.

The Artificial Neural Networks (ANN) are mostly used for pattern recognition and analyze complex data. When an ANN is combined with a sensor array, the number of detectable chemicals is greater than the number of sensors. Less selective sensors can be used with this approach. Once the ANN is trained for chemical vapor recognition, the sensor data is propagated through the network. As this is simply the series of vector-matrix multiplications, unknown chemicals can be rapidly identified in the field.

Applications:
Environment Monitoring:
Huge amount of hazardous waste is generated by nuclear or likewise weapons production. There is need for new and developing technologies for environmental restoration and managing the waste in a cost effective manner. This means development of portable, inexpensive systems that are capable of real-time identification of the contaminants in the field is necessary. Electronic nose fits this category.
Other environmental applications include toxin identification, fuel mixture analysis, oil leakage detection, house-hold odor detection, factory emission monitoring.

Medicine:
The sense of the smell is important to physicians; electronic nose can be used as diagrammatic tool. An electronic nose can examine odor from body, and identify possible problems.

Food Industry:
Currently, this is the biggest market for this kind of device. It can be used to augment or replace the panels of human experts. Potential applications of the electronic nose in food industry are inspection of food quality by odor, fish inspection, fermentation control, etc.