The Graphene Revolution: The weird science of the ultra-thin (Hot Science) by Clegg Brian

Author:Clegg, Brian [Clegg, Brian]
Language: eng
Format: epub, mobi
ISBN: 9781785783777
Publisher: Icon Books Ltd
Published: 2018-07-04T16:00:00+00:00

The Eureka moment

Just producing graphene was a remarkable breakthrough in itself, but what would change the Manchester discovery from something merely interesting into a whole new potential field of applications came when the team began to try out the substance’s physical capabilities. Geim describes his Eureka moment with graphene coming when they had got to work on its electrical properties. This was easier said than done. It’s one thing to have an ultrathin slice of graphite on a piece of sticky tape or oxidised silicon substrate; quite another to be able to test its reaction to electricity.

Novoselov and Geim used tweezers to transfer one of their thinnest flakes to a pristine substrate, then applied tiny spots of silver paint to make electrical contacts to the material. This was an impressive bit of micro-manipulation. The graphene crystal was only about the width of a human hair, making it around 20 nanometres across, and was not as yet a distinct single layer, with several sheets of graphene still together. Lacking any more appropriate technology, the pair applied the silver paint using a toothpick and steady hands. It took a good number of attempts to get it right. But when they did, the result was impressive.

Not only did the material prove to be highly conductive, graphene’s resistance – the ease with which an electrical current flows through it – was modified when it was brought near to an electric field. We’ve already come across the concept of fields a number of times – for example, when Geim levitated a frog using a magnetic field – but it would be useful to clarify exactly what they are before going any further, as electric fields become extremely important when dealing with small-scale electronics.

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