Το δρόμο για την construction φακών επαφής οι οποίοι θα παρέχουν νυχτερινή όραση στον χρήστη τους ανοίγει η δουλειά ερευνητών του University of Michigan, who created the first sensor room temperature light who can perceive the full infrared spectrum.
Unlike comparable sensors that are currently commercially available, this sensor does not require bulky refrigeration equipment to operate.
"We can make the whole project extremely thin," said Zahoji Zong, assistant professor of electrical engineering / computer engineering. "It can be placed in a contact lens or embedded in a mobile phone".
Infrared light starts at wavelengths slightly larger than visible red light, and extends to wavelengths that reach one millimeter. Infrared vision is best known for its use in locating people and animals in the dark, as well as heat leakage, but it can also be used to monitor blood flow, identify chemicals in the environment, and other purposes.
Unlike the visible spectrum, which conventional cameras "see" with a chip, infrared vision requires a combination of technologies. Also, sensors should be at very low temperatures.
The key here was graphene, which allowed detection of the entire infrared spectrum, plus visible and ultraviolet light. However, until now it has not been viable for use in the field because it cannot "capture" enough light to produce a detectable electrical signal.
"The challenge for the current generation of graphene-based sensors is their sensitivity is low—a hundred to a thousand times lower than what a commercial device would require,” says Zhong.
Zhong and Professor Gerard Mourou worked with students to design a new way of partreatmentof electrical signal. Instead of trying to directly measure the electrons released when light hits the graphene, they magnified the signal by "looking" instead at how light-induced electrical charges on the graphene affect a nearby current.
"Our work is a forerunner in the identification of light. Our vision is to be able to adopt this mechanism on other platforms, materials and devices, "adds Zong.
The resulting device is already less than a nail, and it can be further reduced. "If we incorporate it into a contact lens or other wearable devices, it extends vision. It provides another way of interacting with the environment, "says the professor.
The device is described in detail in paper under the title "Graphene photodetectors with ultra-broadband and high responsivity at room temperature "published in Nature Nanotechnology".
