If you have ridden an airplane recently, you probably know the tedious process of airport security checks. All passengers go through this, and, as a result, the procedure as a whole can take a long time. In addition, searching a person with a metal detector while asking you to take off your shoes, belts, changes, cell phones, and other metals is uncomfortable as well as troublesome. Fortunately, new methods that can eliminate all this trouble and make airplane travel a lot smoother have been developed.
One of the methods is tetrahertz scanning. Tetrahertz scanning uses T-rays, which is a low-energy electromagnetic wave with a frequency of 1012 Hertz. When these light waves are passed through the passengers and their possessions, the difference in the natural electromagnetic wave emission from the body and concealed objects gives information as to whether the person is hiding something beneath his clothes. Terahertz radiation, unlike other scanning technologies, can go through materials such as paper, clothing, and plastics while remaining harmless to humans. As a result, terahertz beams can reveal explosives or complex pharmaceutical substances, something that x-rays cannot. Checking the passengers with tetrahertz waves will facilitate security guards’ jobs and improve the efficiency at airport security checks. However, not only are they impractical at the moment, terahertz systems are expensive to produce since they need lasers, liquid helium-cooled detectors, and big optical benches.
Another possible alternative is mass spectroscopy, which acquires a sample of swab from the passengers’ clothing or air collected around them to calculate the mass-charge ratio of ions. The data can promptly sense traces of substances such as explosives or drugs.
“If there is something disrupting the emissions, we see it,” says Gary Tryon of Brijot Imaging Systems, one of several companies developing detection technologies. He adds that the technology can quickly spot plastics, glass, narcotics, explosives, and even cash beneath passengers’ clothing.
Government has a high interest in these detecting technologies. Brijot Imaging Systems signed a contract with the government of the United Kingdom to install its systems at UK airports and ports, receiving more than $2 million in return.
On February 13, a “Clear Prize” has been offered in New York by the Clear firm, which has already been providing innovative airport checks for a fee. The company is looking for any solution that will lower the price of the process while improving the effectiveness and will even award $500,000 to the winner.
“We’re looking at moving things that are conceptual or in the lab to things that we can deploy,” says company CTO Jason Slibeck. He says that more than 150 individuals, start-ups, defence contractors, and universities have shown an interest in the prize.
“T-rays have the potential to revolutionise security screening for dangerous materials such as explosives,” says Dr. Stefan Maier of Imperial College. “Until now it hasn’t been possible to exert the necessary control and guidance... for it to have been usable in real world applications. We have shown with our material that it is possible to tightly guide T-rays along a metal sheet, possibly even around corners, increasing their suitability for a wide range of situations.”