July 2009

New research shows that Graphene may be very useful as an interconnector in computer chips. In widths as narrow as 16 nanometers, graphene has a current carrying capacity approximately a thousand times greater than copper while providing improved thermal conductivity.

A team from the Georgia Institute of Technology has performced this research. Our measurements show that these graphene nanoribbons have a current carrying capacity at least two orders of magnitude higher than copper at these size scales. said Raghunath Murali, a senior research engineer in Georgia Tech’s Nanotechnology Research Center.

One of graphene's intrinsic features is ripples, similar to those seen on plastic wrap tightly pulled over a clamped edge. Induced by pre-existing strains in graphene, these ripples can strongly affect graphene's electronic properties, and not always favorably.

If the ripples can be controlled, however, they can be used to advantage in nanoscale devices and electronics, opening up a new arena in graphene engineering: strain-based devices.

UC Riverside's Chun Ning (Jeanie) Lau and colleagues now report the first direct observation and controlled creation of one- and two-dimensional ripples in graphene sheets. Using simple thermal manipulation, the researchers produced the ripples, and controlled their orientation, wavelength and amplitude.

Northwestern University scientists have found a new, easy way to make graphene - using ordinary camera flash. The scientists exposed Graphite Oxide (which is cheap and widely available) to a camera flash, at room temperature. The flash triggers a de-oxygenation of the Graphite-Oxide.

Strem Chemicals will make stacked Graphene Nanofibers for Catalyx Nanotech.

Stacked Graphene Platelet Nanofibers are grown via a patented process that decomposes carbon containing gases in the presence of metal catalyst particles. The structure of the stacked graphene platelet nano fibers consists of graphene sheets oriented perpendicular to the growth axis like a stack of cards, spaced 0.34nm apart.

Researchers from the Nano-Device Laboratory research at the University of California - Riverside (UCR) and a laboratory at Rensselaer Polytechnic Institute (RPI) says low-frequency noise in a double-gate graphene transistors is low...

The team has designed and built single-layer graphene transistors with two gates: the back gate made of degenerately doped silicon wafer and the metallic top gate separated from the graphene device channel by HfO2 (a material recently introduced by semiconductor industry for conventional silicon transistors).

Scientists from Princeton were awarded a 3M$ grant from the US Air Force to study new fuel additives made of graphene (nanocatalysts) can help engines be more efficient and clean. The Air Force is interested in this because it may help make aircrafts fly faster.

The particles were already shown to help fuels ignite and burn faster, by lowering the temperature at which the fuel ignites. The grant will help the scientists understand why is that, and what kind of particles will work best.

Graphene Energy are on track on have a graphene-based ultra capacitor by year's end. This will have at least twice the storage capacity of commercially available ultracapacitors.

Ultracapcitors promises to be a cost-effective, high-power and high-capacity energy storage solution. Unlike batteries, Ultracapacitors can store and deliver energy in very short time, thus making them most suitable for high power density applications. Graphene Energy are using Graphene for the capacitor electrodes with expectation of power densities surpassing any other known form of activated Carbon electrodes due to its large and readily accessible surface area.

Researchers find that graphene’s electrons are behaving like a nearly perfect liquid — highly turbulent with extremely low viscosity. Such properties emerge as graphene approaches the quantum critical point, a phase transition that breaks the rules of ordinary physics. While a block of ice melts into water only within a narrow temperature range, the transition to a perfect liquid is believed to happen at a wide range of temperatures above this quantum critical point.

To understand the dynamics of graphene’s interacting electrons, Markus Müller of the Abdus Salam International Center for Theoretical Physics in Trieste, Italy, and colleagues used quantum kinetic theory to calculate the ratio of graphene’s viscosity to its entropy — a measure of gloopyness to disorder in the system. Graphene’s ratio comes close to the theoretical lower bound that physicists have calculated for that ratio, and close to the low ratio observed in quark-gluon plasma, the superhot state of matter that existed just after the Big Bang. Instead of behaving like a gas, the quark-gluon plasma behaved more like a soup with extremely low viscosity, physicists learned in experiments at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory on Long Island.

Interactions of charged particles like electrons, known as Coulomb interactions, are usually ignored when studying graphene, comments physicist Daniel Sheehy of Louisiana State University in Baton Rouge. But the new work reveals the importance of graphene’s Coulomb interactions, he says. It shows the electrons are strongly interacting.

Researchers make "artificial graphene" - or at least a device that has the potential to behave like artificial graphene. They created a two-dimensional electron gas of very high purity confined in an AlGaAs/GaAs quantum well. On top of this, they grew a honeycomb network of nanosized pillars that modulate the electric potential in the two-dimensional electron gas, analogous to carbon ions in the graphene lattice. According to their calculations the electronic dispersion due to this hexagonal superlattice can be Dirac-like. Although the appearance of Dirac points in the electronic energy spectrum of such structures still awaits final experimental verification, the authors provide preliminary evidence that features in the observed spectrum are indeed consistent with the calculations.

Artificial Graphene may have some advantages over natural graphene - like high purity, spectrum tuning and shaping in geometries with perfect edges.

Researchers from Rice University in Texas found a new way to make graphene from graphite oxide. The team have carried out a thorough analysis of NMR spectroscopic data on graphite oxide to identify the various oxygen structures present within the material, and then worked out an efficient way to eliminate them by reduction.

Graphene made by novel reduction strategy image

The team used this information to devise a novel reduction strategy by first deoxygenating the graphite oxide sheets with sodium borohydride, followed by dehydration with concentrated sulphuric acid, and a final step of heating, or annealing. They say that their new method makes for more 'pure' graphite that any other reduction method.