Researchers at the University of Michigan have created the first full-spectrum light detector that can be used in contact lenses and smartphones for night vision.
The light detector is more convenient than traditional night vision devices used by soldiers and hunters, which need large built-in cooling units to work correctly, according to the Huffington Post. Night vision allows people to see light that cannot be seen by the naked eye and heat radiating from the bodies of people and animals in the dark.
"We can make the entire design super-thin," said Dr. Zhaohui Zhong, assistant professor of electrical and computer engineering at the university. "It can be stacked on a contact lens or integrated with a cell phone."
Infrared imaging systems need different technology to view the range of infrared, and infrared detectors are usually cooled to make them more sensitive. The graphene lets the new detector find the whole infrared spectrum while working at room-temperature. One problem the device has is that the graphene is only able to absorb 2.3 percent of the light, which makes it difficult to create an electric signal, the Escapist reported.
The researchers found another way to generate a signal, combining two layers of graphene with an insulator, the Huffington Post reported. Sensors made of graphene pushed together can detect the entire infrared spectrum as well as visible and ultraviolet light.
The addition of an electrical current to the bottom layer of the sandwiched graphene played a role in producing a signal. The infrared light dislodged electrons when it hit the top layer. However, the electric current caused the pattern of electron movement to be amplified and able to be used to rebuild the infrared image, according to Discover Magazine.
Zhong said his team has not yet combined the technology with contact lenses, but it is clear that the option is open, the Huffington Post reported.
"If we integrate it with a contact lens or other wearable electronics, it expands your vision," Zhong said. "It provides you another way of interacting with your environment."
