12-09-2009, 12:35 AM
its internal mechanism , not yet disclosed
any way read this
The inspiration for the Aromascan machine came from a biochemist, Krishna Persaud, who set out in 1984 to create a model of the human nose. This highly sophisticated organ has 30 different types of sensors, with millions of sensors working in parallel. Each sensor can absorb a range of smell molecules on to its surface producing an overlapping response. The information from each sensor is fed to the olfactory bulb, which merges it and produces a pattern of the smell molecules that have been absorbed. It then refers the pattern to the brain, which checks it against its smell memory and says, in effect: 'Yes. I have smelt that before. It's a rose.'
The basis of the Aromascan instrument is a range of conducting polymers, which, like the human sensors, trap smell molecules in their surface structure. This alters the polymer's ability to conduct electricity, and the resulting alteration in signal can be analysed to produce the electronic signature of each smell.This is then matched against a database of smells. The device can be set up to make fine distinctions - for example between Mysore and Brazilian roasts of coffee beans - or for simpler tasks, such as determining whether food is fresh or stale.
The Aromascan instrument can be plugged into any personal computer. The software that analyses the data is a neural network, which learns to identify Brazilian coffee beans or whatever by being exposed to several samples of the bean and building up a database of smells in the same way as the brain.Mr Persaud found the first smell-absorbing polymer through a chance reference in a scientific paper. Since he joined forces with Peter Payne at Umist in 1986, however, a library of 50 polymers has been developed and patented. Professor Payne has become technical director of Aromascan
digitising smells, creating the first electronic nose to equal the power of the human organ. Smells can now be faxed or transmitted by computer, an advance that will transform quality control by allowing food companies, perfume houses or drinks manufacturers to assess freshness, aroma and suitability of ingredients well before they are delivered to the factory.
The development provides the first objective measure of smells, and can monitor the whiff from pig farms, sewage works or chemical factories. The equipment can also be used to detect fires and to monitor wound healing.Users of the technology, developed at the University of Manchester Institute of Science and Technology (Umist), include Coca-Cola, Ford, the European Space Agency, Whitbread, the Brewing Research Institute, water companies, a Japanese grain processing company and the Food Research Association.The company, Aromascan, was spun out of the university in March, and it is planning a full stock market listing later this year.