Adapting technology found in flat screen television sets, scientists have created a thin film that converts infrared light into visible light. The technology could give cell phones, eyeglasses and car windshields cheap, lightweight night vision.
“This device can convert any infrared image into a visible image and would weigh no more than a pair of eyeglasses,” said Franky So, a scientist at the University of Florida who describes his new night vision technology in a recent article in the journal Advanced Materials that was funded in part by advanced technology powerhouse DARPA.
Most night vision devices today use massive amounts of electricity — often several thousand volts, according to So — and heavy, glass lenses that maintain a vacuum to make the night come alive. So’s device takes a radically different turn, replacing glass with thin plastic, eliminating the vacuum and using energy-efficient, organic LEDs.
So does this by using technology borrowed from flat screen TVs. Infrared light enters the film and is detected by the first of seven separate layers, which generates a slight electrical charge. Additional electrical energy — about three to five volts — amplifies that signal, which is then converted back into visible light.
This device converts infrared light into visible light, borrowing from technology found in flat screen televisions
Like most of today’s night vision cameras, So’s device emits an eerie green light. Unlike most night vision technology today, however, So’s design would weigh less than 100 grams (less than a quarter of a pound). Part of that weight is the proof of concept small size — about one square centimeter — but So says that even a full scale device could weigh as little as 10 grams and be only a few microns thick.
In other words, heavy and bulky night vision goggles could be replaced with a thin, lightweight coating weighing less than half a deck of playing cards.
It will take about 18 months to scale up the device for practical applications, such as car windshields, lightweight night vision eyeglasses and cell phones cameras.
“Ten years ago when people talked about putting cameras in cell phones, people asked why would you want to do that,” said So. “Now you cannot find a cell phone without a camera. In the future, you might not be able to find a cell phone without night vision.”
Night vision cell phones could be just the start. So said his team also plans to create cell phones that can see, and more importantly, measure heat as well. A cell phone equipped with heat vision could instantly take a patient’s body temperature to see if they had a fever. A car windshield could make pedestrians crossing the street much easier to see and avoid.
Other scientists are enthusiastic about the new research. “This has a high potential to revolutionize night vision,” said Yongli Gao, a professor at the University of Rochester. “It could be very useful in detecting heat loss from homes to reduce energy consumption, and for military applications as well.”