It is smaller than a book and 30 times more sensitive than a dog's nose: EADS researchers in Munich have developed a new sensor that sniffs out drugs and explosives. Thanks to this "artificial nose", flights are to become safer and police work more effective.
It's every traveller's nightmare: terrorists smuggling a bomb onto an aircraft. Since 11 September 2001 at the latest, fear of terrorist attacks in many situations has become a sad fact of everyday life. And not only aircraft but also trains and public buildings are possible targets. But whilst the threat has grown, countermeasures have remained largely unchanged. In order to detect explosives, the authorities rely on various equipment, including X-ray scanners - and on man's four-legged friend: as dogs have an up to 1,000 times more sensitive sense of smell than humans, they can be trained to sniff out substances such as explosives and drugs.
But, as with every living creature, the sniffer dog's stamina also has its limits: after a maximum of 30 minutes' work, the canine detective needs a break and has to be replaced by another dog. The high training costs for sniffer dogs and the constant effort of keeping them represent further limits. EADS Innovation Works at Ottobrunn near Munich has been working to avoid these shortcomings. It has developed an electronic "artificial nose" that is 30 times better than a dog's capabilities.
The sensor, which fits into a housing the size of a notebook, is based on the ion mobility spectrometer. Here, the gases that chemical substances such as explosives and drugs constantly give off are first sucked into a measuring device. They are then split into electrically charged particles, a process which experts call ionization. The device subsequently sorts the particles in an electric field to establish their mobility. Within seconds, the sensor can determine whether the examined gases originate from dangerous substances such as chemical weapons or explosives.
"The big advantage of this method is that it works using laser beams," explains Johann Göbel from EADS Innovation Works . This new technology allows a pre-selection to take place whereby irrelevant substances such as perfume vapour, for example, are rejected before the actual analysis is made. Two mirrors, between which the laser beam is catapulted back and forth innumerable times, additionally increase the efficiency of the "artificial nose".
Göbel and his colleagues have been carrying out research on this project for around three years. "We are making very good progress with this special technology," he says, demonstrating his satisfaction with what has already been achieved. However, he also sees possibilities to further refine the innovation: "Our next step will be to improve user-friendliness," says the engineer. "We are working on an integrated solution thanks to which the end user does not have to be an analysis expert but is presented with the results in an easy-to-understand format." Moreover, the researchers aim to further miniaturize the instrument so that it can be installed in portable hand-held equipment similar to metal detectors in airports.
Göbel expects that the artificial nose will be ready for the markets in three years. The newly developed technology is currently undergoing practical testing within the framework of a European research project. Through this, EADS is not only increasing its market position in the area of homeland security. Thanks to this gas sensor, EADS researchers are also about to close another gap in the simulation of human senses. For whilst artificial eyes such as night vision equipment and electronic ears such as hearing aids have long since clearly surpassed their biological prototypes, the senses of taste and smell were - until now - harder for the engineers to crack At least for the latter of these human capabilities, simulation now seems to have been achieved - to mankind's own advantage: thanks to its small size, the "artificial nose" can be installed into existing measuring and surveillance equipment, and soon into portable devices too. Integration of this technology into airport and building security systems will help to reduce everyday fear by a long way.
