Gizmorama - July 1, 2015

Good Morning,

According to the article below, it looks like graphene is the new wonder material.

We mentioned it in an earlier issue which you can read here.

What will graphene do next!

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin

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*-- Researchers build mini Jeep that turns tire friction into energy --*
MADISON, Wis. (UPI) - A newly developed nanogenerator could make vehicles more efficient by deriving power from the friction of rolling tires.

The technology works by harnessing the changing electric potential between a vehicle's tires and the road. Researchers at the University of Wisconsin-Madison were recently able to demonstrate the device using a miniature remote-controlled Jeep.

An electrode installed on the tires produces contact charge called the triboelectric effect, which initiates a surge of electrons.The flow of electronics powers LED lights installed on the shrunken four-wheeler.

Scientists are now looking to scale up the technology and use the nanogenerator as a solution to on-the-road energy waste. The emerging technology was recently detailed in the journal Nano Energy.

"The friction between the tire and the ground consumes about 10 percent of a vehicle's fuel," Xudong Wang, a material scientist at UW-Madison, said in a press release. "That energy is wasted. So if we can convert that energy, it could give us very good improvement in fuel efficiency."

The energy potential, researchers say, is dependent on the size and weight of the vehicle. The bigger the car, truck or bus, the bigger the potential savings.

"There's big potential with this type of energy," Wang said. "I think the impact could be huge."


*-- Scientists flex graphene to get a stronger current --*
HOUSTON (UPI) - Among scientists, it's a well established truth that graphene is a wonder material, but just how wonderful can it be? What's its potential -- specifically its electric potential?

Researchers at Rice University wanted to find out how graphene's conductivity might change depending on its shape. So scientists flexed and twisted sheets of graphene into different shapes -- a variety of nanotubes and nanocones -- and then ran an electric current through the material.

Flat and tubed graphene has balance that allows electricity to flow smoothly across the layer of atoms. Cone shapes, however, diminish the material's conductivity. By stretching the bonds between carbon atoms in some locations and condensing them in others, the cone shapes altered the electric dipole moments -- the mechanism that governs how polarized atoms interact with electricity.

"While the dipole moment is zero for flat graphene or cylindrical nanotubes, in between there is a family of cones, actually produced in laboratories, whose dipole moments are significant and scale linearly with cone length," Boris Yakobson, lead researcher at the Rice labs where the experimentation took place, explained in a press release.

Using density functional theory to measure how the manipulations affected the cumulative flow of electricity, Yakobson and his colleagues found atoms along the edge also contribute electrically, but analyzing two cones docked edge-to-edge allowed them to cancel out, simplifying the calculations. Researchers were thus able to calculate graphene's electronic flexoelectric effect, and say the technique could be used to predict how more complex shapes, like wrinkled sheets, will influence conductivity.

The researchers' calculations are detailed in a new paper published in the Journal of Physical Chemistry Letters.

The strategic manipulation of the flow of electrons may improve graphene's use in the development of flexible touchscreens and other complex electronics.

"One possibly far-reaching characteristic is in the voltage drop across a curved sheet," Yakobson said. "It can permit one to locally vary the work function and to engineer the band-structure stacking in bilayers or multiple layers by their bending. It may also allow the creation of partitions and cavities with varying electrochemical potential, more 'acidic' or 'basic,' depending on the curvature in the 3-D carbon architecture."

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