It may seem like the stuff from spy and superhero movies but scientists have created “the first room-temperature light detector that can sense the full infrared spectrum” which, according to researchers at the University of Michigan, can be made so thin that it can be easily stacked on night vision contact lenses.
Back in 2011 some speculated that Seal Team Six used night vision contact lenses in the operation that killed Osama Bin Laden. Those rumours were never substantiated, but this invention is very real — the research has been published in the journal Nature Nanotechnology by a team at the University of Michigan’s College of Engineering led by Zhaohui Zhong and Ted Norris.
They have achieved this feat inventing “a new way to detect light,” according to Zhong. The detector uses graphene, the one-atom thick layer carbon atoms that was known to capture the entire spectrum but with a very low sensitivity, absorbing only 2.3 per cent of the light that goes through it. That render graphene unusable for sensors, but the team were able to overcome this by amplifying the signal “by looking instead at how the light-induced electrical charges in the graphene affect a nearby current.”
To make the device, they put an insulating barrier layer between two graphene sheets. The bottom layer had a current running through it. When light hit the top layer, it freed electrons, creating positively charged holes. Then, the electrons used a quantum mechanical trick to slip through the barrier and into the bottom layer of graphene.
The positively-charged holes, left behind in the top layer, produced an electric field that affected the flow of electricity through the bottom layer. By measuring the change in current, the team could deduce the brightness of the light hitting the graphene.
The result is a sensor that has the same sensitivity of the bulky, cooled mid- and far-infrared detectors in the market today. One that, amazingly enough, works at room temperature and can be made so thin that you can put it in contact lenses and mobile phones, according to Zhong:
We can make the entire design super-thin. It can be stacked on a contact lens or integrated with a cell phone. 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.
This, and not Google Glass, is what excites me: New ways to transparently expand our senses.