Nose-on-a-chip

Engineers and scientists from three United Kingdom universities are combining to produce, what they claim to be, the world's smallest electronic nose, an industrial device that is able to replicate the odour sensor capability of the human nose.

Electronic noses have been at work for some years in the food, beverage and perfumery industries but their effectiveness is limited because the devices are large, have limited sensitivity and need to be recalibrated frequently.

The UK project aims to combine odour sensors with signal processing components on a single silicon chip about a square centimetre in size. The new instrument will require little power and be small enough to be held in the palm of a hand.

The nose-on-a-chip has brought together experts from the universities of Leicester and Warwick in the English Midlands, and Edinburgh in Scotland.

In common with most existing electronic noses, the sensing part of the new device will consist of arrays of electrically conductive polymers. The system intends to process and interpret the signals in a way much more akin to biology.

At Warwick University, Professor Julian Gardner is assembling novel mechanisms for channelling the odours on to the sensor arrays. He explained: ``We are taking recent developments in the fields of nanotechnology and polymer physics to design novel microsystems that are able to mimic our nasal passages and olfactory sensors."

At Edinburgh, Dr Alister Hamilton's team is devising ways to integrate the whole system on to a single silicon chip. He said: ``We are designing analogue circuits that interface to the sensor array developed at Warwick and sending signals into some analogue circuits that mimic the mammalian olfactory system. We are using parallel analogue computation strategies that are derived from biology rather than implementing a conventional digital processor. By concentrating on very low power-consumption analogue circuits we hope to produce a system with long battery life.''

For further information please contact Dr Tim Pearce at the University of Leicester.