View Feed
group-icon
Coffee Room
Discuss anything here - everything that you wish to discuss with fellow engineers.
12943 Members
Join this group to post and comment.
Farjand
Farjand • Jul 7, 2011

Graphene Manufacturing Flaws Exposed; Buffalo University Suggest Remedies

Graphene - The most researched material today is known for its properties which have astonished mankind in 21st century. Graphene is a one atom thick material arranged in a hexagonal pattern. Some of its properties include a fast and efficient heat transfer, and a superb electrical conductivity. Perhaps this is the reason that it is nowadays considered a magic material. However don’t be surprised if the magic material does not unveil its magic. A group of scientists have exposed some flaws which could hamper its properties.

[​IMG]
Mapping of Electric cloud of Graphene

A team of researchers from University of Buffalo collaborating with the Molecular Foundry at Lawrence Berkeley National Laboratory, National Institute of Standards and Technology (NIST) and SEMATECH have found out that the manufacturing process which are utilized in manufacturing products from Graphene can leave some ‘wrinkles’ which can negatively impact its electrical conducting properties. Employing synchrotron: scanning transmission X-ray microscopy and near edge X-ray absorption fine structure (NEXAFS), the group was able to identify a cloud of electron surrounding Graphene material. NEXAFS is a type of absorption spectroscopy. The electrons in the cloud are responsible for a faster flow of electric current from the sheet. However spectrographic studies employed by the group suggested that the peaks in the wrinkles can seriously degrade the quality of its properties. The same was also degraded by some contaminants introduced during the manufacturing processes. Both the wrinkles and the contaminants were responsible for distortion in the electron cloud.

[​IMG]
Dotted lines show regions in Graphene structures sloped at different angles

Studying on how to eliminate the contaminants, the scientists stumbled upon a simple technique- Heating! The University of Buffalo scientists found that heating Graphene sheet up to 150o Centigrade could remove the anomalies introduced in the structure. The wrinkles simply get absorbed back again in the material. Speaking of the manufacturing processes, Sarbajit Banerjee said that the flaws can arise in the sheet by a simple folding process. Whenever the sheet is bent, it is unable to show its optimal properties which are only possible with a straight sheet. The electrons have to jump across Graphene which can be thought of like a bent pillow. However a simple heating process can solve the purpose. The study points out correctly at the flaws and also suggests remedies. It seems that we can now expect some never thought of inventions/discoveries in near future. The research in this regards was published in the June 28 issue of Nature communications.

Source: University of Buffalo

Share this content on your social channels -