European researchers lead way on super-thin technology
A free-hanging membrane of carbon just one atom thick, the world's thinnest material, has been created by a team of European researchers. Their findings could be used to make super-fast electronic components and speed up the development of drugs. Their work, which was partly funded by the EU's Sixth Framework Programme, is published in the latest edition of the journal Nature. In 2004, Professor Andre Geim of the University of Manchester and his colleagues discovered a new class of materials which are effectively sheets of atoms just one atom thick. The discovery caused great excitement in the physics world, but experiments on thin films suggested that these new materials would simply break up if they were not firmly attached to a substrate. In this latest piece of research, Professor Geim, together with colleagues from Germany and the Netherlands, put this theory to the test. Graphene is a single layer of carbon atoms joined together in a pattern which looks like chicken wire. The researchers created a sheet of graphene on a silicon chip, and attached the graphene to a delicate scaffold of gold wires. They then dissolved the chip in acid, leaving the graphene sheet hanging freely on the scaffold. The graphene membrane had an area of around one square micrometre, and contained around 30 million carbon atoms. Despite its thinness, the membrane proved to be remarkably stable. The key to its strength lies in the fact that the layers are not perfectly flat, but gently crumpled, a property which renders the material stable in a similar way to corrugated cardboard. 'Perfect 2D atomic crystals cannot exist, unless they are of a limited size or contain many crystal defects,' the researchers write. 'The observed microscopic corrugations of 2D graphene in the third dimension provide another, unexpected way to reconcile the high quality of graphene with its thermodynamic stability.' 'Two dimensional membranes are completely different to conventional three dimensional crystals,' commented Dr Jannik Meyer of the Max Planck Institute for Solid State Research. 'We are just beginning to discover their fundamental properties and research their possible applications.' The scientists believe these new materials could be used as sieves to filter light gases, or to make miniature electro-mechanical switches. They could also be used as a support for individual molecules being studied under electron microscopes. This could be of significance for medical researchers, as it could allow the rapid analysis of the atomic structures of complex molecules. 'This is a completely new type of technology - even nanotechnology is not the right word to describe these new membranes,' said Professor Geim. 'We have shown that very thin membranes with the thickness of just one atom can be produced. And we believe that this technology can also be adapted for real applications. However, the real challenge is to make such membranes cheap and readily available for large-scale applications.'
Countries
Germany, Netherlands, United Kingdom