Duke University engineers have developed a novel sensor that is more efficient, versatile and cheaper for potential use in such applications as airport security scanners and collision avoidance systems for aircraft, cars or maritime vessels.
The researchers fabricated a unique material, known as a metamaterial, that acts as a lens to image scenes using fewer components than conventional detectors. Because of the properties of this man-made material, much of the additional equipment needed for conventional detector systems – like lenses, mechanical positioners and data storage or transmissions devices – are not required.
The material itself is a thin laminate with row-upon-row of tiny squares etched onto copper, each one of which is tuned to a different frequency of light. The material is flexible and durable enough to be attached to a wall, wrapped around corners or even laid on the floor like a rug, making it an inexpensive alternative for a variety of sensing applications.
The new system works with microwave light and produces two-dimensional images. The researchers are currently exploring moving the technology to three-dimensional capability in real-world settings.
The Duke researchers reported their findings Jan. 18 on-line in the journal Science. The research was supported by the Air Force Office of Scientific Research.
"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, " said John Hunt, a graduate student working in the laboratory of senior investigator David R. Smith, William Bevan Professor of electrical and computer engineering at Duke's Pratt School of Engineering.
As an example, Hunt 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, creating an effectively larger aperture. The scanning waves travel through clothing, but skin or other objects reflect the waves. The new device can scan the entire field at once, which would allow for faster and more efficient screening, the researchers said.
"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 metamaterial is made of thousands of tiny apertures that can detect a wide spectrum of frequencies, allowing it to obtain a more global image of the scene, the researchers said.
"Each individual element of the metamaterial is tuned to narrow frequency," said Tom Driscoll, a post-doctoral fellow from the University of California – San Diego currently working in the Smith lab. "Together the individual elements scan the entire range to capture information about a scene very quickly."
"This system allows us to collect and compress the image during collection, instead of later, averting the detector, storage and transmission costs associated with conventional imaging of a scene," Driscoll said.
Duke University: http://www.duke.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Fabric laced with silver nanowires traps heat and could even be warmed up like an electric blanket
Speaking just one language will no longer be a barrier to global communication if Microsoft has its way.
A look at how the telephone has changed over the years, and how it's changed us
From now on you'll be matching images to prove you're not a bot – and training Google's computers to recognise real-world objects at the same time
Pirate Bay, a controversial file-sharing website that has survived for more than a decade, was knocked offline following a raid in Sweden.
Students across the country are getting a crash course in coding during Computer Science Education Week
When shown these phishing emails, 94 percent of security professionals were fooled. Could you do better? Take the quiz to find out
"Digital immigrants" in other countries could soon guide robots around your house. Some find that creepy – and that could be just the start of the trouble
Computers have already tried their hand at sports commentary – now they're picking highlight clips by scanning videos for telltale signs of excitement
Viewers are increasingly tuning in for TV shows and movies on Netflix, Hulu, Amazon streaming and other services