A new airport security system based on smell sensors has been developed by German researchers.
The prototype system HAMLeT (hazardous material localisation and person tracking) was developed at the Fraunhofer Institute for Communication, Information Processing and Ergonomics FKIE in Wachtberg, Germany.
The system can be placed behind a corridor wall and "sniff" potentially hazardous chemicals through highly-sensitive smell sensors. It then processes the acquired data and can track an individual's movement through a secondary sensor laser network.
The sensor chips possess oscillating crystals, and when the electronic noses capture chemical molecules, the oscillation frequency changes.
The frequency of oscillation is different for various substances.
The sensor data fusion process allows complex algorithms that help keep a precise image of pedestrian flow, to connect a particular smell with a specific individual.
The system recently went on trial with the German armed forces and helped track down five terrorists carrying hidden explosives.
The scientists are currently engaged in refining the prototype's algorithms in order to reduce the false alarm rate.