The resources deployed since 9/11 to stop terrorist attacks have worked on a variety of levels—better human intelligence, additional cameras, more electronic snooping, and more alert citizens. But part of ending the kind of mayhem that happened at the Boston Marathon last Monday will involve better high-tech systems for detecting explosives.
Despite billions spent every year by the Pentagon's Joint Improvised Explosive Device Defeat Organization to develop better bomb detection, when it comes to sensitivity in ferreting out bomb-making material, there's still nothing better than well-trained dogs, say experts. But a number of companies are trying to do better, since people's best friend comes with several disadvantages: they get tired, become distracted, need to eat and sleep regularly, and suspects or suspicious packages have to be within range of a dog's nose.
The gains possible through easier and cheaper bomb detection go beyond U.S. borders.—unexploded landmines, for example, kill 15,000 to 20,000 people a year, according to the United Nations. There's also big money involved, with millions in government contracts up for grabs for companies that develop the next generation of anti-explosives detection systems.
All of that makes bomb detection a growth industry, with more resources likely coming its way since last week. Here are seven new tools and technologies that could stop the next terrorist with a bomb in a backpack.
1. Laser scanners: Remote laser scanners are designed to detect explosives from dozens of yards away. Currently used on the battlefield to identify improvised explosive devices, these work by directing pulses of light at suspicious objects or areas and then reading the resulting vibrations—explosives emit unique patterns. Researchers at Oak Ridge National Laboratory say they're developing a laser-based device that can detect explosives residues from up to a football field away. It will be ready for commercial development within one to two years, they say.
2. Fluorescent explosives detectors: These use "amplifying fluorescence polymers" —which go dim in the presence of explosives because the explosives bind with the polymers—to indicate the presence of bomb materials like TNT in the air. The company FLIR Systems makes handheld machines weighing 2.5 pounds that provide explosives detection levels similar to what a dog can offer, according to the company. They're already used by U.S. troops, but the unit has to get close to the target or suspect to detect the threat.
3. Terahertz (THz) spectroscopy equipment: THz detectors, being developed by researchers at Rensselaer Polytechnic Institute and NASA's Jet Propulsion Laboratory, can be pointed at suspicious objects or people from 10 or more meters away and send a short pulse of harmless radiation toward the suspicious material. The detector uses the result of the interaction between the radiation and the material to identify the atomic "signature" present. This is then matched against a library of signatures for explosives. One developer of the technology says a THz detector is so sensitive that tiny detectors could be mounted above the front doors of an airport to identify anyone entering who has even a trace amount of explosives on their clothes—likely for anyone making and transporting bombs.
4. Sniffer bees: Under a government contract, British researchers have developed a portable handheld sensor that holds 36 honeybees taught with food rewards to recognize the odors associated with a range of explosives, like Semtex, C4, and gunpowder. The sensor draws in air from whatever is being examined and passes it over the bees. If the sample has a substance that the bees are trained to detect, they stick out their proboscises in expectation of food—and a display on the device captures their reaction. The bees can be trained in minutes, say the researchers, and their sensitivity is comparable to that of sniffer dogs.
5. Ion mobility vapor detection: The company Implant Sciences markets a handheld "sniffer" that uses ion mobility spectrometry technology—which measures the speed of molecules in an electrical field—to detect suspicious vapors emitted from clothing or packages. Weighing in at about 11 pounds, it takes between 5 and 30 seconds to scan a suspicious item and has to be used in close proximity to the item. It also detects illegal drugs.
6. 3-D imaging: The U.S. Transportation Security Administration awarded a contract last fall for the next generation of weapons and explosives detection scanners in airports. The new scanners use radio waves to scan passengers, and their software automatically detects threatening objects made of any type of material—no human judgment or analysis required. People are still needed to search suspects when the machine spots possible bomb material though.
7. Nanotech detectors: Researchers at the University of California, Santa Barbara have designed a detector that uses nanotechnology to detect airborne explosive particles at minute concentrations, say the researchers. A fingerprint-sized silicon microchip holds a "microchannel"—a liquid channel that's twenty times smaller than the thickness of a human hair —that traps individual molecules and sends them to the other part of the mechanism, a laser-powered mini spectrometer, which identifies them. The detectors, already available from California-based company SpectraFluidics, could become as common as smoke detectors in public places in sniffing out vapors from explosives, says the university.