Graphene Material; Changing the Rules of Discovery

A thin flake of ordinary carbon, just one atom thick, lies behind the Nobel Prize in Physics. Andre Geim and Konestanin Novoselov have shown that carbon in such a flat form has exceptional properties that originate from the remarkable world of quantum physics. It could not have been easier to obtain graphene, the miraculous material that come ordinary graphite such as is found in pencils. However, the most simple and obvious things are often form over view.

“Graphene is a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite.”

Graphene is amazing. Or at least, it could be. Made from a layer of carbon one-atom thick, it's the strongest material in the world, it's completely flexible, and it's more conductive than copper. Discovered just under a decade ago, the supermaterial potentially has some unbelievable applications for us in the not so distant future.

Graphene is an allotrope of carbon. In this material, carbon atoms are arranged in a regular hexagonal pattern. Graphene can be described as a one-atom thick layer of the mineral graphite (many layers of graphene stacked together effectively form crystalline flake graphite). Among its other well-publicised superlative properties, it is very light, with a 1-square-meter sheet weighing only 0.77 milligrams. The properties of graphene, carbon sheets that are only one atom thick, have caused researchers and companies to consider using this material in several fields. The following survey of graphene applications introduces you to many of these uses.

Konstantin Novoselov and Andre Geim

In essence, graphene is an isolated atomic plane of graphite. From this perspective, graphene has been known since the invention of X-ray crystallography. Graphene planes become even better separated in intercalated graphite compounds. In 2004, physicists at the University of Manchester and the Institute for Microelectronics Technology, Chernogolovka, Russia, first isolated individual graphene planes by using adhesive tape. They also measured electronic properties of the obtained flakes and showed their unique properties. In 2005 the same Manchester Geim group together with the Philip Kim group from Columbia University  demonstrated that quasiparticles in graphene were massless Dirac fermions. These discoveries led to an explosion of interest in graphene.

The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov at the University of Manchester "for groundbreaking experiments regarding the two-dimensional material graphene".

Some graphene applications:

          The properties of graphene, carbon sheets that are only one atom thick, have caused researchers and companies to consider using this material in several fields. The following survey of graphene applications introduces you to many of these uses. Mega-fast uploads. We're talking a whole terabit in just one second.

Graphene is just one atom thick, but remarkably strong. Scientists have suggested that it would take an elephant, balanced on a pencil to break through a single sheet. Already dubbed a miracle material due to its strength, lightness, flexibility, conductivity and low cost, it could now enter the market to dramatically improve telecommunications, researchers said. Using 'miracle material' graphene in telecommunications could dramatically make the internet a hundred times faster, a new study has found. Researchers the Universities of Bath and Exeter have demonstrated for the first time incredibly short optical response rates using graphene, which could pave the way for a revolution in telecommunications. Ordinarily optical switches respond at rate of a few picoseconds - around a trillionth of a second. Through this study physicists have observed the response rate of an optical switch using 'few layer graphene' to be around one hundred femtoseconds - nearly a hundred times quicker than current materials.

Plug your phone in for five seconds and it would be all charged up. The downside here is that you won't be able to use a dead phone as an excuse anymore. Lithium-ion batteries that recharge faster. These batteries use graphene on the surface of the anode surface. Defects in the graphene sheet (introduced using a heat treatment) provide pathways for the lithium ions to attach to the anode substate. Studies have shown that the time needed to recharge a battery using the graphene anode is much shorter than with conventional lithium-ion batteries. 

Touchscreens that use graphene as their conductor could beslapped onto plastic rather than glass. That would mean super thin, unbreakable touchscreens and never worrying about shattering your phone ever again. Just a single sheet of graphene could produce headphones that have a frequency response comparable to a pair of Sennheisers, as some scientists at UC Berkeley recently showed us.

High-power graphene supercapacitors would make batteries obselete. Ultracapacitors with better performance than batteries. These ultracapacitiors store electrons on graphene sheets, taking advantage of the large surface of graphene to provide increase the electrical power that can be stored in the capacitor. Researchers are projecting that these ultracapacitors will have as much electrical storage capacity as lithium ion batteries but will be able to be recharged in minutes instead of hours.

       The ability to build high frequency transistors with graphene is possible because of the higher speed at which electrons in graphene move compared to electrons in silicon. Researchers are also developing lithography techniques that can be used to fabricate integrated circuits based on graphene.
        Researchers have built a solar cell that uses graphene as a electrode while using buckyballs and carbon nanotubes to absorb light and generate electrons; making a solar cell composed only of carbon. Graphene could pave the way for bionic devices in living tissues that could be connected directly to your neurons. So people with spinal injuries, for example, could re-learn how to use their limbs.

What if we actually had a clear solution for cleaning up the tainted water near Fukushima? Scientists at Rice say graphene could potentially clump together radioactive waste, making disposal is a breeze. 

Several potential applications for graphene are under development, and many more have been proposed. These include lightweight, thin, flexible, yet durable display screens, electric circuits, and solar cells, as well as various medical, chemical and industrial processes enhanced or enabled by the use of new graphene materials.

Reference:

• Nobel Foundation announcement
• http://onnes.ph.man.ac.uk/nano/Publications.html#Graphene
• Geim, A. K. and Novoselov, K. S. (2007). "The rise of graphene"
• H. P. Boehm, A. Clauss, G. O. Fischer, U. Hofmann (1962). "Das Adsorptionsverhalten sehr dünner Kohlenstoffolien". Zeitschrift für anorganische und allgemeine Chemie 316 (3–4): 119–127
• http://en.wikipedia.org/wiki/Graphene
• http://www.techgig.com/tech-news/editors-pick/Graphene
• http://www.emsl.pnl.gov
• http://gizmodo.com/5988977/9-incredible-uses-for-graphene
• http://www.graphene-info.com/tags/graphene-applications
• http://www.thehindubusinessline.com/news/science/graphene-may-boost-internet-speed-100-times/article4914735.ece
• http://www.understandingnano.com/graphene-applications.html
• www.tumblr.com
• http://www.aegindia.org/2012/10/paperthin-smartphones-strong-thin-graphene/214807.html
• http://www.popsci.com/gadgets/article/2011-06/first-graphene-based-circuit-step-toward-graphene-computer-chips
• http://www.humods.com/2009_01_01_archive.html
• http://www.engineerjobs.com/content/2013/4-ways-graphene-changes-everything.htm
• #science #vinayakpattar #vinayak #pattar #jncasr #sjcit #nano #nanotech #bangaloreuniversity #physics #vinayakpattarblog