Sunday, October 26, 2008

Nano Technology is finaly comming out of the lab with real world potential

Nano Technology has been a thing of science fiction for far to long, and it's about time it has come out of story books and failing lab tests to the real world from proven lab results and actual production materials that can possibly change the world for the better.

Ben Wang, director of Florida State's High-Performance Materials Institute said that they
have actually demonstrated materials made from nanotechnology, called Buckypaper, that are capable of being used on flying systems.

It takes upward of five years to get a new structural material certified for aviation use, so Wang said he expects Buckypaper's first uses will be for electromagnetic interference shielding and lightning strike protection on aircraft.

Electrical circuits and even natural causes such as the sun or Northern Lights can interfere with radios and other electronic gear. Buckypaper provides up to four times the shielding specified in a recent Air Force contract proposal, Wang said.

Typically, conventional composite materials have a copper mesh added for lightning protection. Replacing copper with buckypaper would save weight and fuel.

Wang demonstrated this with a composite model plane and a stun gun. Zapping an unprotected part of the model caused sparks to fly. The electric jolt, though, passed harmlessly across another section shielded by a strip of buckypaper.

Other near-term uses would be as electrodes for fuel cells, super capacitors and batteries, Wang said. Next in line, buckypaper could be a more efficient and lighter replacement for graphite sheets used in laptop computers to dissipate heat, which is harmful to electronics.

The long-range goal is to build planes, automobiles and other things with buckypaper composites. The military also is looking at it for use in armor plating and stealth technology.

"Our plan is perhaps in the next 12 months, we'll begin -- maybe -- to have some commercial products," Wang said. "Nanotubes obviously are no longer just lab wonders. They have real world potential. It's real."

The scientific discovery that led to buckypaper virtually came from outer space.

In 1985, British scientist Harry Kroto joined researchers at Rice University for an experiment to create the same conditions that exist in a star. They wanted to find out how stars, the source of all carbon in the universe, make the element that is a main building block of life.

Everything went as planned with one exception.

"There was an extra character that turned up totally unexpected," recalled Kroto, now at Florida State heading a program that encourages the study of math, science and technology in public schools. "It was a discovery out of left field."

The surprise guest was a molecule with 60 carbon atoms shaped like a soccer ball. To Kroto, it also looked like the geodesic domes promoted by Buckminster Fuller, an architect, inventor and futurist. That inspired Kroto to name the new molecule buckminsterfullerene, or "buckyballs" for short.

For their discovery of the buckyball -- the third form of pure carbon to be discovered after graphite and diamonds -- Kroto and his Rice colleagues, Robert Curl Jr. and Richard E. Smalley, were awarded the Nobel Prize for chemistry in 1996.

Separately, Japanese physicist Sumio Iijima developed a tube-shaped variation while doing research at Arizona State University.

Researchers at Smalley's laboratory then inadvertently found that the tubes would stick together when disbursed in a liquid suspension and filtered through a fine mesh, producing a thin film -- buckypaper.

The secret of its strength is the huge surface area of each nanotube, said Ben Wang, director of Florida State's High-Performance Materials Institute.

"If you take a gram of nanotubes, just one gram, and if you unfold every tube into a graphite sheet, you can cover about two-thirds of a football field," Wang said.

Now carbon nanotubes (CNT) are getting in on the act with nanotechnologists working out how to grow nanotube reinforcements for polymers in an ideal manner.

Researchers from Trinity College have developed a scalable inexpensive technique to grow grid patterns of nanotube arrays. To maximise the effect of CNT reinforcement on a polymer thin film, while minimizing nanotube content, a controllable way of varying the volume fraction of CNTs within the composite is needed. In order to do this, the inter-grid spacing can be tailored as required giving a simple method of controlling the volume fraction of nanotubes grown on substrates.

The research work by Werner J. Blau, Dr. Emer Lahiff, Andrew I. Minett and Dr. Kentaro Nakajima is expected to lead to incorporation of CNTs in polymer matrices within flat panel displays, sensors, flexible electronic devices and actuators.

Troy, N.Y. - Researchers at Rensselaer Polytechnic Institute have created robust quantum models to compare key characteristics of copper and CNTs.
"If you go to the nanoscale, objects do not behave as they do at the macroscale," said Saroj Nayak, an associate professor in Rensselaer's Department of Department of Physics, Applied Physics, and Astronomy, who led the research team. "Looking forward to the future of computers, it is essential that we solve problems with quantum mechanics to obtain the most complete, reliable data possible." "Given the data we collected, we believe that carbon nanotubes at 45 nanometers will outperform copper nanowire."

"Other researchers have developed ways to produce hydrogen with mind-boggling efficiency, but their approaches are very high cost," says Craig A. Grimes, professor of electrical engineering. "We are working toward something that is cost effective."

A greener, less expensive method to produce hydrogen for fuel may eventually be possible with the help of water, solar energy and nanotube diodes that use the entire spectrum of the sun's energy, according to Penn State researchers.

Currently, the steam reforming of natural gas produces most of our hydrogen. As a fuel source, this produces two problems. The process uses natural gas and so does not reduce reliance on fossil fuels; and, because one byproduct is carbon dioxide, the process contributes to the carbon dioxide in the atmosphere, the carbon footprint.

Grimes' process splits water into its two components, hydrogen and oxygen, and collects the products separately using commonly available titanium and copper. Splitting water for hydrogen production is an old and proven method, but in its conventional form, it requires previously generated electricity. Photolysis of water solar splitting of water has also been explored, but is not a commercial method yet.

Grimes and his team produce hydrogen from solar energy, using two different groups of nanotubes in a photoelectrochemical diode. They report in the July issue of Nano Letters that using incident sunlight, "such photocorrosion-stable diodes generate a photocurrent of approximately 0.25 milliampere per centimeter square, at a photoconversion efficiency of 0.30 percent."

"It seems that nanotube geometry is the best geometry for production of hydrogen from photolysis of water," says Grimes.

The photoelectrochemical diodes function the same way that green leaves do, only not quite as well. They convert the energy from the sun into electrical energy that then breaks up water molecules. The titanium dioxide side of the diode produces oxygen and the copper titanium side produces hydrogen.

Although 0.30 percent efficiency is low, Grimes notes that this is just a first go and that the device can be readily optimized.

"These devices are inexpensive and because they are photo-stable could last for years," says Grimes. "I believe that efficiencies of 5 to 10 percent are reasonable."

Grimes is now working with an electroplating method of manufacturing the nanotubes, which will be faster and easier.

There is still far more Nanotech materials coming out of the labs and into reality, I just wanted to shed some light on the subject in general. I really believe in the idea and concepts that nanotechnology can bring us into a much brighter and cleaner future.