Electronic noses in the future can sniff and identify things which will have applications in almost every field. These e-noses are very expensive but the latest technology owes to deliver them are affordable price levels in the near future. The technology has advanced over a period of 20 years and is now looking for commercial entry. E-noses can replace manual inhaling to recognise objects in day-to-day life.
The reason for this major breakthrough has been the improvements in printed electronics and conducting polymers. Conducting polymers act as transducers and sense the chemicals with odour and convert them into charges. By having an array of such sensors different types of smell can be detected with a single piece of equipment. The basic idea behind electronic smelling is pattern recognition. The e-nose first samples the gas and the sensor array generates a pattern which is compared with stored patterns in a signal processor. Several complex algorithms are proposed for the pattern recognition function. The e-noses are very flexible and many fold better than today's lock and key sensors. By storing different patterns in the database a single e-nose can be trained to identify any object. By having a system that can update its library with new patterns in real time practical situations can be handled easily.
The most important application of e-nose is in bomb detection which can save human lives. Other applications are in sensing tainted wine, decayed consumables, packaging, greenhouse gases and in medical field. It could be a household appliance very soon.