David Kirkpatrick

May 1, 2010

Cool nanotech image — atomic moire pattern of graphene

Filed under: et.al., Science, Technology — Tags: , , , , , — David Kirkpatrick @ 5:11 pm

Check this out:

Caption: Moiré patterns appear when two or more periodic grids are overlaid slightly askew, which creates a new larger periodic pattern. Researchers from NIST and Georgia Tech imaged and interpreted the moiré patterns created by overlaid sheets of graphene to determine how the lattices of the individual sheets were stacked in relation to one another and to find subtle strains in the regions of bulges or wrinkles in the sheets.

Credit: NIST

Usage Restrictions: None

Related news release: Seeing moire in graphene

February 22, 2010

A tool to stop “drive-by downloads”

If this thing works, everyone ought to use to it.

From the link:

Researchers at SRI International and Georgia Tech are preparing to release a free tool to stop “drive-by” downloads: Internet attacks in which the mere act of visiting a Web site results in the surreptitious installation of malicious software. The new tool, called BLADE (Block All Drive-By Download Exploits), stops downloads that are initiated without the user’s consent.

“When your browser is presented with an [executable file] for download, it’s supposed to prompt you for what to do,” said Phil Porras, SRI’s program director. But software can also be pushed onto an unsuspecting user’s computer without ever asking for permission.

In the fourth quarter of 2009, roughly 5.5 million Web pages contained software designed to foist unwanted installs on visitors, according to Dasient, a firm that helps protect websites from Web-based malware attacks. Such drive-by downloads target computers that are not up-to-date with the latest security patches for common Web browser vulnerabiltiies, or are missing security updates for key browser plug-ins, such as Adobe’s PDF Reader and Flash Player. Attackers use software called exploit packs, which probe the visitor’s browser for known security holes.

October 30, 2009

Improving dye-sensitized solar cells

Efficiencies are going up and costs and holding steady or falling. All this bodes well for the future of solar power.

From the link:

Dye-sensitized solar cells are flexible and cheap to make, but they tend to be inefficient at converting light into electricity. One way to boost the performance of any solar cell is to increase the surface area available to incoming light. So a group of researchers at Georgia Tech has made dye-sensitized solar cells with a much higher effective surface area by wrapping the cells around optical fibers. These fiber solar cells are six times more efficient than a zinc oxide solar cell with the same surface area, and if they can be built using cheap polymer fibers, they shouldn’t be significantly more expensive to make.

The advantage of a fiber-optic solar-cell system over a planar one is that light bounces around inside an optical fiber as it travels along its length, providing more opportunities to interact with the solar cell on its inner surface and producing more current. “For a given real estate, the total area of the cell is higher, and increased surface area means improved light harvesting and more energy,” says Max Shtein, an assistant professor of materials science and engineering at the University of Michigan who was not involved with the research.

Solar on fiber: An optical fiber (left) is covered in dye-coated zinc-oxide nanowires (closeup, right). Both images were made using a scanning electron microscope.
Credit: Angewandte Chemie

April 9, 2009

Nanogenerator/solar cell combo

This sounds like a very promising nanotechwith practical applications. I enjoy blogging on both nanotechnology and solar energy research, but it’s always more interesting when the breakthrough are somewhere close to actual real world application.

From the Technology Review link:

Nanoscale generators can turn ambient mechanical energy–vibrations, fluid flow, and even biological movement–into a power source. Now researchers have combined a nanogenerator with a solar cell to create an integrated mechanical- and solar-energy-harvesting device. This hybrid generator is the first of its kind and might be used, for instance, to power airplane sensors by capturing sunlight as well as engine vibrations.

Nanogenerators typically use piezoelectric nanowires–hairlike zinc oxide structures that generate an electrical potential when mechanically stressed–to produce small amounts of power. The first such devices were made by Zhong Lin Wang, a professor at Georgia Tech and director of the institute’s Center for Nanostructure Characterization. Wang hopes that nanogenerators will one day eliminate the need for batteries in implantable medical sensors, and will eventually generate enough power to charge up larger personal electronics.

Nano hybrid: A dye-sensitized solar cell (top) and a nanogenerator (bottom) sit on the same substrate in the new device. Credit: Xudong Wang

Nano hybrid: A dye-sensitized solar cell (top) and a nanogenerator (bottom) sit on the same substrate in the new device. Credit: Xudong Wang

September 23, 2008

Carbon nanotube coated electrodes increase efficiency

Good news for neurological devices. Coating electrodes with carbon nanotubes makes them much more efficient, longer lasting and less prone to side effects.

From the link:

Researchers led by Edward Keefer at the University of Texas Southwestern Medical Center developed a simple method for coating electrodes with carbon nanotubes. The coated electrodes were better at recording neural activity than were bare electrodes when implanted in mice and in a monkey. Importantly, the coated electrodes provided less-noisy recordings than bare ones did. They also required less power to operate.

And the nanotubes enhanced the electrodes’ ability to both record and stimulate neural activity more than any other coating previously reported. Today’s neural prosthetics are good at sending electrical signals but not at receiving them, says Ravi Bellamkonda, director of the Neurological Biomaterials and Therapeutics group at Georgia Tech. Thus, the batteries in deep-brain stimulators–implanted devices used to treat Parkinson’s–last only three years because the devices are constantly on. “You want to seeif the neuron is quiet,” says Bellamkonda. A feedback-enabled device that powered off when not needed could potentially use the same battery for a few more years.

In these scanning electron microscope images, electrodes coated with carbon nanotubes, like the one on the right, are more conductive and better at interfacing with nervous tissue. The electrode on the left is bare.

Neural nanotubes: In these scanning electron microscope images, electrodes coated with carbon nanotubes, like the one on the right, are more conductive and better at interfacing with nervous tissue. The electrode on the left is bare.

July 17, 2008

Nanotech fighting cancer

Filed under: Science, Technology — Tags: , , , , — David Kirkpatrick @ 1:58 am

This is a pretty exciting breakthrough in fighting cancer through nanotechnology.

Hit the link for a video, and here’s the lede:

Scientists at Georgia Tech have developed a potential new treatment against cancer that attaches magnetic nanoparticles to cancer cells, allowing them to be captured and carried out of the body. The treatment, which has been tested in the laboratory and will now be looked at in survival studies, is detailed online in the Journal of the American Chemical Society.

“We’ve been able to use magnetic nanoparticles to capture free-floating cancer cells and then take them out of the body,” said John McDonald, chair of the School of Biology at Georgia Tech and chief research scientist at the Ovarian Cancer Institute. “This technology may be of special importance in the treatment of ovarian cancer where the malignancy is typically spread by free-floating cancer cells released from the primary tumor into the abdominal cavity.”