We’re just learning about the many uses of graphene, but it can do everything from removing salt molecules from water to becoming super-thin body armor. It also does something really cool when with light: it readily absorbs light energy and fires off multiple electrons. Unfortunately, graphene is also really thin (as thin as a strand of hair), so it can’t actually absorb a lot of light on its own. The Michigan team, though, figured out a way to change that by using two layers of graphene with a dielectric in between them. When light hits the top layer of graphene, the electrons generated travel to the bottom layer through the dielectric material. This process increases the number of electrons, creating about 100 times more of them, making a phototransister that has a sensitivity about equal to a standard digital camera.
But how does all this create infrared vision in a contact lens? Graphene is sensitive to multiple wavelengths of light outside of the visible spectrum, including infrared and ultraviolet. The graphene sandwich created by the Michigan team is currently sensitive to visible light and infrared. Because of its thinness, the team suggests that integrating it with a contact lens would be a good use of this new technology. Not only could this be useful for military applications, but it also has applications in medicine as well.