| Posted: May 4, 2010 |
Cell phones could double as night vision devices |
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(Nanowerk News) Call it Nitelite: The newest app for cell phones might be night vision.
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A University of Florida engineering researcher has crafted a nickel-sized imaging device that uses organic light-emitting diode technology similar to that found in cell phone or laptop screens for night vision. But unlike night vision goggles, which are heavy and expensive, the device is paper-thin, light and inexpensive, making it a possible add-on to cell phone cameras, even eyeglasses, once it is enlarged.
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"Really, this is a very inexpensive device," said Franky So, a UF professor of materials science and engineering. "Incorporating it into a cell phone might not be a big deal."
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So is the lead author of a paper about the infrared-to-vision device that appeared in a recent issue of the journal Advanced Materials. Do Young Kim, a postdoctoral associate in materials science and engineering, co-authored the paper and collaborated with So on the project.
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Standard night vision goggles use a photocathode to convert invisible infrared light photons into electrons. The electrons are accelerated under high voltage and driven into a phosphorous screen, producing greenish images of objects not visible to the eye in darkness. The process requires thousands of volts and a cathode ray tube-like vacuum tube made of thick glass. That is why the goggles tend to be bulky and heavy.
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So's imaging device replaces the vacuum tube with several layers of organic semiconductor thin film materials. The structure is simple: It consists of a photodetector connected in series with an LED. When operating, infrared light photons are converted into electrons in the photodetector, and these photo-generated electrons are injected into the LED, generating visible light. The device – versions range from millimeter- to nickel-size -- currently uses glass, but it could be made with plastics, which would make it lightweight.
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Conventional night vision goggles or scopes weigh 1 to 2 pounds, with price tags ranging from hundreds to thousands of dollars. Sized for cell phones, So said, his imaging devices weigh just a couple of ounces and would be inexpensive to manufacture because factories could use the same equipment used today to make laptop screens or flat-screen televisions.
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So said other applications could include night vision technology for car windshields, or even for standard glasses to use at night.
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So's research is funded by Nanoholdings LLC, a Connecticut-based diversified nano-energy company that licenses and develops nano-energy discoveries in partnership with universities and their scientists, and the Defense Advanced Research Projects Agency. A UF startup company, NirVision, a portfolio company of Nanoholdings, was recently formed to further develop and commercialize the technology for different market segments.
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