If not being able to see in the dark scares you so much, this latest research has the potential to free you from that fear. Recently, researchers from the University of Michigan have developed a new infrared sensor, and this sensor may eventually be applied to contact lenses in the future, allowing them to have night vision. It does sound like a spy movie, but it's about to become a reality.

 

Researchers at the University of Michigan have developed a sensor capable of capturing visible and infrared light, with graphene sandwiched between the lenses, without the need for bulky cooling. In general, mid-infrared and far-infrared sensors typically have to operate at extremely low temperatures. The team has already built a prototype of glasses that are smaller than a fingernail and can shrink even further.

 

The assistant professor of electrical engineering and computer science and his team have improved the process by which graphene produces electrical signals by subjecting the graphene to a "sandwich" interlayer process, where an insulating spacer is placed between two graphene sheets, with a bottom layer of current passes through.

 

When light hits the top layer graphene, the device releases electrons, creating positively charged holes. Then, under the quantum tunneling effect, the electrons pass through the insulating layer in the middle and reach the graphene layer at the bottom. At this time, the positively charged holes left on the upper layer of graphene will generate an electric field and affect the current of the lower layer of graphene. By measuring the change in current, it was possible to deduce the brightness of the light shining on the upper layer of graphene. Zhong Zhaohui said that the new method brings the sensitivity of mid-infrared and far-infrared sensors to a new height for the first time, which is completely comparable to traditional infrared sensors that require cooling devices to operate.

 

The lens is as sensitive as a digital camera's silicon image sensor, taking full advantage of the properties of a graphene "super sensor." Electrons in graphene can move at high speeds like photons, dozens of times faster than photons in silicon. It acts as a "hot carrier", and the resulting effects can be measured, processed, and transformed into images. The researchers also noted that graphene is the material of choice for ultra-broadband photodetectors, capable of absorbing the ultraviolet to far-infrared spectrum. According to data, the wavelength of infrared light is between 760 nanometers and 1 mm, which is non-visible light with a wavelength longer than that of red light. It is divided into three types: near infrared, middle infrared and far infrared.

 

Team members say they have designed extremely thin graphene photoreceptors that can be added to contact lenses or integrated with phone lenses. Experts say this technology can be expanded to military, security, medical and other fields, such as enhancing the vision of soldiers at night, as well as groups who need to observe their surroundings in the dark.