Sensing Danger: Advances in Detecting Explosives at Airports

posted: 22 January 2008 1:36 p.m. ET

: Amazingly, bees might provide a big part of the solution to the important and complex problem of detecting home-made explosives planted by terrorists at airports. Training bees Pavlov-fashion to respond visibly by sticking out their tongues when their sensitive scent receptors detect certain chemicals provides a surprisingly accurate means of detecting explosives hidden in bags and containers. And the training and use doesn't harm the bees. Credit: Cidalia Castro

Cane sugar, paraffin wax, acetone and hydrogen peroxide -- these items may sound like a list of things that lurk under the kitchen sink, but they are increasingly being used by terrorists as ingredients to make potentially dangerous explosives.

With the use of homemade explosives on the rise in terror attacks, it becomes ever more important that airport screening devices are as innovative as aviation’s would-be attackers, detecting potential threats with speed and accuracy. Cue the next generation of extra-sensory detectors.

One new technology that is currently pushing the boundaries of what screeners can and can’t detect is employing a group of very unexpected little helpers -- honeybees.

Pavlov's bees

By using a Pavlovian technique, the bees are conditioned in as little as 20 minutes to recognize a range of substances by feeding them sugar syrup each time they are exposed to the chemicals’ smell. The bees then associate these substances with the food reward and subsequently stick out their tongues – an unambiguous reflex reaction that can easily be recorded, and is far more reliable than the ‘trained’ reaction from other animals such as dogs.

“It initially came as a surprise to us but the bees seem to be able to learn to detect any chemical, as long they can ‘smell’ it,” Mathilde Briens, research and development manager for Inscentinel, told Airport World.

A minimum of 12 bees -- which are not harmed in any way during the process -- are strapped into a box that is aimed at the target, and their reaction is then recorded on a screen.

“Because the bees are so small, our big selling point is the fact that they can be brought in so close to the target,” Briens pointed out. “The bees were met with skepticism at first, but we have more than proven their potential. Now we just need to deploy the best system to make sure the bees are in the right conditions to perform to the best of their ability.”

The bees can be housed in a range of applications, from handheld detectors to lab-based analyzers for high throughput screening.

“We are also currently in the process of making the bee handling operations mechanical, designing a system that will automatically load the bees into their separate harnesses and train them to make the system even more user friendly,” added Briens.

Hand-held sniffer devices

But with or without bees, the convenience and accuracy of hand-held devices that can ‘sniff’ out harmful substances certainly hold great appeal for airports.

In Israel, a country renown for its advanced security systems, a portable device is now in use that mimics the human nose to identify homemade explosives. Launched by Herzliya-based Scent Detection Technologies (SDT), the ‘Mini Nose’ comprises an analyzer and a sampling unit, is non-radioactive and can sniff out trace levels of explosive chemicals -- even in harsh, dusty or humid ‘real world’ environments.

“Maintaining sensitivity in all conditions is crucial,” pointed out SDT’s vice president for business development, Doron Shalom. “The reality today is that we’re dealing with terrorists that can easily manufacture explosives in their kitchen.”

Having been tested rigorously in conjunction with the Israeli Ministry of Defense, the Mini Nose is now being used at security checkpoints at gateways across the US, Europe and Asia-Pacific as well as in Israel.

Meanwhile, another innovator who has been following his nose is Phillip Thomas, president and CEO of Implant Sciences Corporation, who confirms considerable industry interest in his portable ‘Quantum Sniffer.’

Another system with no need for a radioactive core, the sniffer is totally non-contact and self calibrates itself within a matter of seconds after detecting explosives -- unlike most detectors currently in use, which need to actually touch the trace residue and must be manually recalibrated by an engineer after coming into direct contact with explosives.

“As well as producing fast results and being extremely easy to use, the fact that the sniffer self-calibrates also saves screeners a huge amount of time," said Thomas. "It can detect virtually all the common substances that are of concern to us today, ranging from traditional explosives like black powder, TNT and C4 to the peroxides, which are now being used to produce homemade explosives.”

The sniffer systems have been certified in Russia, with portable versions currently in use at airports in the Moscow area, but Thomas confirms that the biggest installment to date has been in China.

“We have our largest installed base in China, and have recently announced that we’ll be shipping in units for use during the Beijing Olympic Games,” he enthused. “The technology will be deployed at various airports in and around Beijing and we hope to start conducting further tests at another gateway in China shortly.”

Large-scale screening

Beyond the portable devices, Thomas believes that the technology can be deployed on a much larger scale, screening passengers, baggage, cargo and even moving vehicles with a high level of reliability.

“We’ve been awarded a multi-million dollar grant by the TSA in the US and we’re working closely with them to develop a next-generation passenger portal,” Thomas revealed. “The portals currently in use have proved very expensive and have experienced a lot of reliability problems, so we’re using the sniffer technology to create a more advanced version that will operate much more quickly and with much higher reliability.”

Indeed, the tests that Implant has so far conducted on a next-generation turnstile flash portal have shown that, using the sniffer system, a passenger can pass through in just 1 to 3 seconds. When compared with the 15 to 20 seconds currently needed in the existing portals, this could mean increasing the number of passengers processed from around 30 an hour to up to 1,000.

With growing congestion at major gateways around the world and air traffic figures on the rise, versus the vital need to identify and eradicate any kind of security threat, this seems somewhat of a necessity -- especially when the portal can then automatically recalibrate itself in a matter of seconds.

This technology can, of course, then be extended to hand luggage, checked in baggage and cargo, or, as Thomas put it, “any other sort of ‘threat’ in motion.”

“Ultimately, we see this technology being combined with visualization systems such as X-ray and back scatter, bringing multiple sensors together to create a complete screening package,” he added. “This represents a significant step forward for airport security and will address a lot of issues that have needed a solution for some time now.”

Whatever threats may lie ahead, it certainly seems that the next generation of sensory detectors are not to be sniffed at.