Stories tagged University of Manchester

Aug
02
2012

Graphene fixes itself: Graphene uses loose carbon atoms to re-knit its damaged structure.
Graphene fixes itself: Graphene uses loose carbon atoms to re-knit its damaged structure.Courtesy kso
As a happy accident, scientists from the University of Manchester learned that graphene (sheets of carbon atoms arranged in a honeycomb crystal lattice, just one atom thick – think chicken wire) can repair itself spontaneously. Graphene is a semi-metal that conducts electricity very easily. It has potential uses in not only electronics, but also DNA sequencing, desalination, and it has been found to be a great antimicrobial.

The Manchester researchers were originally trying to understand how metals react with graphene, which will be an important part of incorporating it into everyday electronic devices. They found, much to their dismay, that some metals actually damaged graphene’s structure by punching holes in its neatly-arranged lattice. This is not a good thing if you’re trying to create a graphene-based device. However, quite unexpectedly, the graphene started to mend itself spontaneously, using nearby loose carbon atoms! As stated by the Scientific Director at the Daresbury Laboratory, Dr. Quentin Ramasse, this could mean the “difference between a working device and a proof of concept with no real application.” It also means that graphene just jumped to the top of my “baller carbon allotropes” list.

Mar
11
2007

Graphene transistor tiniest ever

Graphene from graphite: Graphene is one layer of carbon atoms linked chickenwire-like within graphite. Mattman723 / CC BY-SA 2.5
Graphene from graphite: Graphene is one layer of carbon atoms linked chickenwire-like within graphite. Mattman723 / CC BY-SA 2.5
Only one atom thick and less than 50 atoms wide, these "nano" transistors are the smallest in the world. Graphene transistors originally produced at the end of 2004 were very “leaky”. Transistors are like a valves, controlling the flow of an electric current. If they cannot be totally turned off, the leakage results in drained batteries.

Leakage problem solved

Now the Manchester team has found an elegant way around the problem and made graphene-based transistors suitable for use in future computer chips.

Graphene remains highly stable and conductive even when it is cut into strips of only a few nanometres wide.
All other known materials - including silicon - oxidise, decompose and become unstable at sizes tens times larger.
Professor Geim does not expect that graphene-based circuits will come of age before 2025. DailyTech

Professor Andre Geim and Dr Kostya Novoselov from The School of Physics and Astronomy at The University of Manchester reveal details of these transistors, in the March issue of Nature Materials.

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