Innovation: Digital smell of success: An electronic nose offers commercial advantages over the human equivalent

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A BRITISH company has succeeded in 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.

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, and this element of the company's research will continue at the university.

Umist set up a company 18 months ago called Odourmapper, which has since sold 25 instruments to commercialise the research. Then the university's technology transfer arm, Umist Ventures, persuaded a local investor, Harold Morley, who had previously supported the foundation of Tepnel Diagnostics, another Umist spin-off, to invest in the company. It was renamed Aromascan and set up in Crewe.

Aromascan will sell its systems direct to the analytical instruments market, but recognises it needs joint ventures and licensing deals to develop the vast range of potential applications. Alan Syms, managing director, said the company was close to a number of deals, including one with a large healthcare company to develop diagnostic equipment, one with a food company working on quality control applications, and another with a water company to develop environmental monitoring systems.

Aromascan says using its equipment will cost about pounds 2 per test compared with the pounds 15- pounds 25 for a test that analyses food ingredients by breaking them down to their individual constituents. It will also work 24 hours a day, unlike human (or in the pet food industry, dog and cat) sensory panels. And although the human nose rapidly becomes desensitised after exposure to a smell, Aromascan can go on sniffing.

Smells are made up of volatile molecules and evolve over time. Like the human nose, Aromascan can detect that mayonnaise has gone off as soon as the lid is taken off the jar. But it can also sense this some hours later, when the smell profile has changed and the human nose can no longer detect the change.


THE Bisto Kids would not go aaah if their favourite gravy acquired a different smell. This need for consistency of smell is a big preoccupation of food companies. In addition to this application of the Aromascan electronic nose:

Ford is using it to monitor exhaust emissions.

Coca-Cola is using it for quality control in Coke production.

The European Space Agency is using it as a fire detector in its rockets - if a cable begins to overheat volatile smell molecules are released.

Whitbread is monitoring its brewing with the device - if a fermentation goes wrong, a whole production batch is lost.

The University Hospital of South Manchester has used it in a trial to detect wounds that were becoming infected before there were any visual signs.

A water company is using it to monitor and abate odours at a sewage works.

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