Researchers from the University of Michigan have developed a super-thin infrared sensor that could lead to the development of night-vision contact lenses.

With the help of graphene, a single layer of carbon atoms, the researchers developed the sensor that can be integrated into smartphone cameras and with contact lenses for night vision.

It was already known by scientists that graphene can absorb complete infrared spectrum visible light and ultraviolet light. One of the difficulties was to coax the material in such a way that it absorbs enough light by which an electrical signal can be produced.

This led the researchers to devise a new method to increase the sensitivity of graphene so that electrical signal can be generated from infrared light. In the method, the researchers took two layers of graphene and added an insulating barrier between the two.

To give a final touch to the process, they added an electrical current to the bottom later. When infrared light touched the surface of the top layer of graphene, it discharged electrons and presence of electrical current at the bottom, the electron movement got amplified and could be used to reconstruct the image.

The design is very small and the new graphene sensor works at normal temperature. The researchers have built a small size of the design, but it can be made even smaller. Prof. Zhaohui Zong said that the design is so thin that it can be stacked on contact lens.

"If we integrate it with a contact lens or other wearable electronics, it expands your vision. It provides you another way of interacting with your environment", said Prof. Zhaohui Zong. The study has been published in the journal Nature Nanotechnology.