Siemens, the German electronics group, has developed a smell sensor for its new generation of mobile telephones: the phone will “ping” if exposed to gas, including bad or food-scented breath. Mobile phones already have an ear and, thanks to in-built cameras, they have an eye. If, as planned, the new sensors are built into the phone chips, mobiles will also have a nose.

“Our ceramic sensorised chips are smaller than one millimetre but they can pick up the smallest quantities of gas,” said Maximillian Fleischer, a researcher at Siemens. His colleagues are already comparing the smelling phone favourably with bloodhounds, French pigs that hunt truffles and canaries that were traditionally used in mine-shafts to sniff out traces of gas.

The nano-technology inside the phone responds to chemical reactions in the atmosphere and generates an electronic signal. The phone lets out a sharp note to breath tainted by a curdled stomach, cabbage or even the mildest of onions.

“Every girl about to kiss her boyfriend will need a phone like this,” said Bravo, the teenagers’ magazine, which is usually written in breathless prose. The magazine did not mention boys, but they presumably could also chew a mint or two after checking with the phone.

One of the main targets in Germany will be beer drinkers. Since the beer is so fizzy it tends to produce a large amount of stomach gas. Drunks with more expensive taste, too befuddled to realise that their breath is sickly sweet with port, will also benefit.

The gas-sensitive phone could revolutionise behaviour on public transport. Many of the sensors are strong enough to pick up other people’s gaseous emissions or body odours.

Stuck in the rush-hour underground with its usual mix of human aromas, phones are likely to “ping” as they have never pinged before.

Passengers, steered by their phones, could avoid fellow travellers with halitosis or other problems. The new phones seem set to be the modern equivalent of the leper’s bell.

The phone has serious functions, some of which could save lives. Asthmatics could be alerted to an impending attack. Joggers, cyclists and other outdoor athletes worried about ozone levels will be given a greenhouse gas warning before their hearts start to race. The phone, according to its designers, is much more effective than conventional fire alarms. “Our sensors signal a warning before it really starts to burn,” Dr Fleischer said. Normal fire sensors react only to dense smoke and a rapid increase in heat.

Siemens is developing other sensor technology together with the company Infeneon and the Fraunhofer Institute in Munich. Young women already use mobile phones with cameras to check the state of their make-up and the smell phones are also likely to end up in the cosmetic bag, an essential contribution to modern grooming.

• A Moscow call service has become popular in helping women to get rid of undesired suitors. “Hello. Welcome to the Moscow refusal service. The person who left you this number does not want to speak to you. Goodbye,” is what men hear when they call a number given to them. (AFP)

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