January 18, 2013
Cheap, Efficient Sensor Could Revolutionize Airport Security
Lee Rannals for redOrbit.com — Your Universe Online
Duke University Engineers have developed a sensor for technologies like airport security scanners that is more efficient, versatile and cheaper.The team fabricated a material, known as a metamaterial, that acts as a lens to image scenes using fewer components than conventional detectors. The properties of this material make it require less equipment than conventional detector sensors.
The material is a thin laminate with row-upon-row of squares that are etched onto copper, each one of which is turned to a different frequency of light. It is flexible and durable enough to be attached to a wall, wrapped around corners, or even laid on the floor like a rug.
The new system works with microwave light and produces two-dimensional images. Researchers are working on making the technology three-dimensional image capable.
"By taking advantage of the unique properties of these metamaterials, we were able to create a system capable of microwave imaging without lenses or any moving parts, " John Hunt, a graduate student working in the laboratory of senior investigator David R. Smith, said in a statement.
He said that in many security situations, imaging systems move a single sensor device with a small aperture in front of the body of the subject. The scanning waves travel through clothing, but skin or other objects reflect the waves.
With this new device, airport security teams will be able to scan the entire field at once, allowing for faster and more efficient screening, according to the researchers.
"Using conventional systems such as airport security cameras or collision-detection devices, you have to wait for a scan to complete before you can see an image, while the new system can scan an entire range at once," Hunt said.
The material is made up of thousands of tiny apertures that are able to detect a wide spectrum of frequencies, which helps the material to obtain a more global image of the scene.
"Each individual element of the metamaterial is tuned to narrow frequency," Tom Driscoll, a post-doctoral fellow from the University of California — San Diego (UCSD) currently working in the Smith lab, said in a statement. "Together the individual elements scan the entire range to capture information about a scene very quickly."
He said that the system allowed the researchers to collect and compress the image during collection, instead of averting the detector, storage and transmission costs associated with conventional imaging of a scene.
The researchers wrote about their findings in the January 18 online edition of the journal Science.