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Research that shows how light can control the electrical properties of graphene could lead to the development of super-sensitive sensors.
Researchers at the National Physical Laboratory (NPL), along with a team of scientists from across the UK, Europe and US, have made the discovery about the world’s thinnest material, which could be used to develop electronic graphene-based devices and sensors, such as to detect smoke and gases.
The latest research shows that when graphene is combined with particular polymers, its electrical properties can be precisely controlled by light and exploited in a new generation of optoelectronic devices. The polymers keep memory of light and therefore the graphene device retains its modified properties until the memory is erased by heating.
The NPL said that similar polymers could be used in the future to translate information from their surroundings and influence how graphene behaves. This effect could be exploited to develop robust reliable sensors for smoke and poisonous gases.
Graphene, which consists of a single layer of carbon atoms arranged in a honeycomb lattice, has been hailed as a “wonder material”. As it does not have volume, only surface, its entire structure is exposed to its environment and responds to any molecule that touches it. This makes it a good material for super-sensors capable of detecting single molecules of toxic gases.
Despite being one atom thick and chemically simple, graphene is one of the strongest materials ever tested and is around 200 times stronger than steel. This means it has the potential to be used in touch-sensitive screens, solar cells, light panels and flexible electronics.
The material’s light weight also makes it suitable to use in satellites and on aircraft, and it is also a phenomenal conductor of electricity. Electrons travel further in graphene than in any other material, making it ideal for high-speed electronics and photonics. Graphene-based integrated circuits could also lead to smaller and more sophisticated computers and mobile phones.
Last year’s Nobel Prize for Physics was awarded for research into graphene, which recognised the many ways it can be used in modern life.
The prize was given to Professors Andre Geim and Konstantin Novoselov, from the University of Manchester, last October, for creating the material seven years ago and the research they had since carried out to understand it. In October 2009, the Engineering and Physical Sciences Research Council (EPSRC) awarded Geim a grant of more than £5 million to investigate the potential of graphene.
At the time of the award, Professor David Delpy, chief executive of the EPSRC said: “This work represents an enormously important scientific development. [Graphene is] an exciting new material that has a huge range of applications and will no doubt bring significant benefits to the UK economy.”
