The way to make contact lenses that provide night vision to their user opens the work of researchers University of Michigan, who created the first sensor room temperature light who can perceive the full infrared spectrum.
In contrast to similar sensors currently on the market, this sensor does not need bulky coolant latest technology equipment in order to function.
"We can make the whole design extremely thin," said Zhaohui Zhong, assistant professor of electrical/mechanical-computer engineering. “It can be placed on a contact lens or integrated into one mobile phone".
Infrared light begins at wavelengths slightly longer than visible red light, and extends to wavelengths up to one millimeter. Infrared vision is best known for its use in detecting people and animals in the dark, as well as heat leaks, but it can also be used to monitor flow bloodto, the detection of chemical substances 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.
Here "key” 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 - one hundred to a thousand times lower than what a commercial device would require," says Zong.
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» που δημοσιεύθηκε στο Nature Nanotechnology".
