Transcript Graphene (Boris Torres

Graphene
Boris Torres
MEEN 3344
Material Science
Graphene
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Graphene is a one-atomthick planar sheet of
carbon atoms that are
densely packed in a
honeycomb crystal lattice.
Graphite itself consists of
many graphene sheets
stacked together.
The carbon-carbon bond
length in graphene is
approximately 0.142 nm.
Graphene production
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Graphene sheets in solid form
(e.g. density > 1g/cc) is
presently one of the most
expensive materials on Earth.
Researchers obtained
relatively large graphene
sheets (eventually, up to 100
micrometers in size and visible
through a magnifying glass)
by mechanical exfoliation
(repeated peeling) of 3D
graphite crystals.
Another method is to heat
silicon carbide to high
temperatures (1100°C) to
reduce it to graphene.
Properties of Graphene
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The resistivity of the
graphene sheet is 10^−6
Ω·cm, less than the
resistivity of silver, the
lowest resistivity substance
known at room
temperature.
Graphene is the strongest
substance known to man.
Its Young's modulus is 0.5
TPa, which differs from
bulk graphite.
These intrinsic properties
could lead to the possibility
of utilizing Graphene for
NEM systems applications
such as pressure sensors,
and resonators.
Properties of Graphene
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Engineering professors at
Columbia University tested
graphene's strength at an
atomic level by indenting a
perfect sample of the
material with a sharp
probe made of diamond.
Electrons move through
graphene with almost no
resistance, generating little
heat. What's more,
graphene is itself a good
thermal conductor,
allowing heat to dissipate
quickly.
Graphene and Applications
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By oxidizing graphene
flakes, and then floating
them in water, the
graphene flakes form a
single sheet and bond very
powerfully called Graphene
oxide paper.
Applications:
 Membranes with controlled
permeability
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Supercapacitors for energy
applications.
Graphene electronics could
be useful for
communications and
imaging technologies that
require ultrafast
transistors.
References
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Graphene http://en.wikipedia.org/wiki/Grapheneaccessed on
March, 29 2009
Graphene Confirmed the World’s Stronged Known Material
http://gizmodo.com/5026404/graphene-confirmed-as-theworlds-strongest-known-material accessed on March, 29 2009
Nanotechnology Reserchers go Ballistic Over Graphene
http://www.nanowerk.com/spotlight/spotid=2340.php
accessed on March 29, 2009
TR10: Graphene Transistors
http://www.technologyreview.com/read_article.aspx?ch=speci
alsections&sc=emerging08&id=20242 accessed on March 29,
2009
Graphene: Charged Up http://www.natureasia.com/asiamaterials/highlight.php?id=77 accessed on March 29, 2009