Future airline passengers may one day forget what it was like to pass through a standard metal detector. A new sensor being developed at Ohio State can detect hidden firearms by using what looks like a simple camera.
The sensor, which could also help airplane pilots navigate in bad weather, works by detecting the natural radiation reflected by everyday objects.
Instead of sending out X-rays to detect firearms, the sensor uses a camera to "see" the natural radiation that a firearm reflects based on its chemical composition.
Paul Berger, professor of electrical and computer engineering and physics, and head of the team developing the sensor at OSU, compared the technology to the way the human eye sees the sun in different colors, depending on what time of day it is.
"The sensor can use radiation and ultraviolet waves to detect certain metals the way the eye perceives the sun," Berger said. "The sensor can see through lighter materials, such as clothing, the way we can see clear through the atmosphere."
The same technology could also help pilots see in the fog by producing an image of the radiation reflected by a runway.
The sensor is still a few years away from being commercially practical, Berger said. Currently, cameras that can detect natural radiation are expensive and large.
Berger and his team is working with silicon wafers to fit cameras and the circuitry required to run the technology into a much smaller, more affordable package.
Patrick Fay, professor of electrical engineering at the University of Notre Dame, has been working with OSU on the project.
"I wouldn't expect it to take long for these devices to begin to be used more widely once the potential cost advantages of this technology become more widely understood." Fay said in an e-mail.
Notre Dame assisted OSU with electrical measurements and analysis of a device Berger's team invented and called a tunnel diode, which detects radio and microwave-frequency radiation.
A diode is a device that typically powers amplifiers for things like stereo speakers. Berger's tunnel diode sensor works much the same way except in reverse - It works with silicon, the material most commonly used in computer chips.
"Because we are able to integrate silicon into these sensors, chip makers could manufacture them much more cheaply," Berger said. "One day, we'll be able to put these things on doors, in the noses of airplanes, anywhere someone can think that might save lives."
Berger describes the sensor in detail in the current issue of the journal IEEE Electron Device Letters, according to the OSU Web site.
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