Huge possibilities, tiny tools Nanotechnology--the science of small--could change the metals industry in a very big way

WWW.THEFABRICATOR.COM MARCH 2001

March 13, 2001

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Nanotechnology is just beginning to blossom as a practical topic of interest for the manufacturing industry. Just how big an impact will nanomaterials have in our lifetimes? We're sure to find out soon.

When comedian Steve Martin told his audiences "Let's get small" in the 1970s, nanotechnology probably registered just above "jab eye with hot poker" on his priority list.

However, nanotechnology and nanoscience—the application and study of particles one-billionth of a meter wide—now are burning their way into the everyday lexicon of physicists, engineers, and even steel manufacturers.

Because forming and manipulating such small pieces of matter have, until recently, dwelt almost exclusively in the realm of science fiction paperbacks and laboratory experiments, the manufacturing community has tended to treat nanotechnology more as a curiosity than a useful workplace tool.

That is changing—rapidly.

Advances in Computing

With the advent of scanning tunneling microscopes (STMs) and then scanning probe microscopes (SPMs) came the ability to view, manipulate, and photograph individual atoms. These tools have enabled research facilities such as Hewlett-Packard Laboratories to seriously explore the possibility of storing one bit of information on a single atom through a process called atomic resolution storage (ARS). HP Labs and several universities are looking into several materials that can be written, erased, and rewritten at densities near the atomic scale.

In addition, early last year, scientists at IBM reported that they had discovered chemical reactions that cause nanoparticles only 4 nanometers in diameter to "self-assemble." Reliable self-assembly being one of the holy grails nanoscientists are seeking, the discovery may pave the way to large-scale use of the phenomenon.

"Self-assembly is one of the intriguing areas of nanoscience," says Dr. S. Tom Picraux, director of the Physical Sciences Group at Sandia National Laboratory, Albuquerque, New Mexico. "The trick is to let chemistry direct self-assembly. Nature's very good at this; we aren't."

Today, engineering on the microscale, by the millionths of an inch, reigns supreme in the world of computing. Microelectromechanical system (MEMS) technology is the standard by which almost all semiconductors and microchips are manufactured today. Many people believe MEMS technology is reaching its functional limit, though, and the hope is that nanoelectromechanical system (NEMS) technology will take the helm when MEMS reaches its proverbial space-heat ratio brick wall.

Getting nanostructures to the complexity that the computer industry is accustomed to at the MEMS level is a "towering challenge," California Institute of Technology professor and researcher Michael Roukes said at a December nanotechnology conference hosted by the American Society of Manufacturing Engineers (ASME). In much the same way, genetic scientists are racking their brains to figure out how to encode very complex algorithmic structures to produce complex parts, he reports.

"We don't know how to do that at all today," Roukes says.

Show Me the Money

Now, the nanosciences finally are getting some major-league funding from Uncle Sam for applications across the spectrum, from energy to computing to manufacturing.

In a January 2000 speech at Cal Tech, former President Clinton announced the federal government's National Nanotechnology Initiative (NNI), a $422 million project headed up by the National Science Foundation, the U.S. Department of Defense, and the U.S. Department of Energy. This initiative—coupled with private research already being done by the likes of IBM, Hewlett-Packard, and the Massachusetts Institute of Technology (MIT)—could propel nanotechnology from laboratory to living room faster than many people realize.

One Technology, Innumerable Possibilities

Mihail "Mike" Roco is a lucky man. As chairman of the National Science and Technology Council's Subcommittee on Nanoscale Science, Engineering, and Technology, Roco gets a ringside seat to one of the most exciting nascent technologies the world has ever seen. In that role, he and the subcommittee are charged with advising the White House on the latest in nanotechnology and its implications.

Roco also is a key figure in the NNI. In addition to its charter members, other federal agencies, including NASA and the National Institutes of Health, are funding the initiative. Several more, the Environmental Protection Agency and the Department of Transportation among them, have expressed interest in joining.

"So it becomes really a cross-cutting initiative" mainly because of the promise it holds for our comprehension of nature, health, wealth, and sustainable development, Roco says.

"All materials, devices, and systems start from the nanoscale," Roco says. "All properties are defined at that level. If one is able to control that level, he can control any human-made object. They all work on the same principles."

The largest application Roco sees for nanoscale materials right now is nanostructured catalysts for the petroleum and chemical industry. The third is medicine, the fourth is nanoelectronics. However, it's the second-largest area—advanced metallic, polymeric, and ceramic materials—that has a few pioneers in the manufacturing industry buzzing about possibilities.

From Sci-Fi to Shop Floor

The NNI has set aside $140 million in fiscal year 2001 to address a series of "grand challenges," among them studying nanostructured "materials by design" that are stronger, lighter, harder, and safer than current materials—and self-repairing.

One company gunning to turn these sci-fi hopes into serious profit is Evanston, Illinois- based QuesTek Innovations LLC, which uses a materials by design method conceived at the Northwestern University Steel Research Group to develop superhard alloy and stainless steels. With this approach, which relies on computerized modeling to test material before it is created, QuesTek has developed several products that it hopes to roll out to customers later this year and in 2002.

The company is asking target customers in four key marketplaces to test-drive its new metals, two of which are case-hardened steel alloys called Ferrium(TM) C69 and GearMet C69, so named in reference to their Rockwell hardness scale ratings. The alloys are being marketed as alternatives to traditional steels for high-volume manufacturing applications such as tools and dies, roll forms, and punches.

"People who are in high-volume manufacturing are really in very competitive marketplaces," Director of Business Development Spike Schonthal notes. "Customers are consistently putting pressure on them to cut costs. There are very few places a manufacturer can go for relief. But certainly, potentially, the most dramatic improvement they can make is increased productivity."

To fabricate its Ferrium and GearMet C69 products, the company uses what it calls a nanoscale M2C strengthening dispersion to form molecular structures that are more atomically dense than what is found in nature. While the outer case has a hardness rating of 69, the inside measures 50 on the Rockwell scale, which gives the new alloy a higher ductility and less brittleness inside while maintaining high strength on the outside.

All of the company's alloys are made into ingots using a standard VIM/VAR steel process, followed by QuesTek's precipitation strengthening method. From there, the material is forged into special shapes or rolled into sheet or plate.

By relying on computer modeling to test the material before it is created, QuesTek "can literally model and optimize a material based on performance needs," Schonthal says. "This system vastly reduces the development time, because right now, materials are created [in an iterative fashion]—you create a bunch, try them, take the best, and get better at it. Much of that can be avoided—really, all of it."

The challenge for QuesTek, like any other company dabbling in new materials, is to find customers who think as highly of the new products as their inventors do.

"We're working backwards [through the process]," Schonthal says. "We need to find markets for materials that have already been developed."

High-resistance Coatings

Nanoparticles already are playing a stealth role in the manufacture of everyday products such as wear-resistant coatings for vinyl flooring and key ingredients for lip balm.

Nanophase Technologies Corp., Romeoville, Illinois, manufactures ultrafine powders in bulk using a vapor phase process, then uses a patented process to coat individual particles, which makes the base material compatible with a customer's application.

Take, for instance, the company's zinc oxide product. By breaking down the basic material into particles that are about 50 nanometers wide and then coating them, Nanophase has created a zinc oxide product that can be formulated to be transparent rather than the traditional white. The product's characteristics won Nanophase a globally exclusive contract with BASF, the German chemical giant, and made it Nanophases's best-selling item.

The company's aluminum oxide and titanium dioxide products already are being used for coating parts on U.S. Navy ships and as durable coatings for a variety of sliding surfaces, says Dr. Donald J. Freed, vice president of business development for Nanophase. It's no stretch to imagine some of the same sprays being used as transparent coatings for metal coil, he says. In addition, Nanophase just signed a contract to provide aluminum oxide coatings to a major manufacturer of vinyl flooring. The coatings will allow the manufacturer to provide a lifetime wear warranty on its flooring, according to Freed.

"Wear coatings are a very important here-and-now market for us," Freed says.

And regardless of how good the company thinks the product is, "it's got to be affordable," Freed says. "The benefit you get has to be taken in context with the economics of the application. If we're in sheet vinyl flooring, that says something."

Possibilities Down the Road

Carbon—it's the building block of life and, in no insignificant way, the building block of all things steel as well. In future forms already being explored on the nanoscale, it may even rival steel as a material of choice for many high-strength applications.

Many of the biggest advances in nanotechnology research have been made in the study of carbon nanotubes, which were first identified as such in the laboratory in 1991. Nanotubes are hollow cylinders of carbon atoms just a few nanometers wide and a few micrometers long.

In terms of how carbon nanotubes may affect industry, "it's hard to say," says Mildred Dresselhaus, an MIT professor and former director of the Office of Science at the U.S. Department of Energy who also happens to be one of the leading researchers in the field. Great strides have been made in identifying how nanotubes behave, but a lot of work remains, she says.

Meanwhile, "the field is moving like gangbusters," and she sees "great possibilities" for using nanotubes to push atoms around in the laboratory, Dresselhaus says. Scientists at the University of California - Berkeley already have experimented with concentric series of nanotubes called fullerenes that, after some manipulation, can telescope just like a sailor's spyglass and be used as probes to manipulate atoms. Work also is being done at Berkeley to explore the use of fullerenes as frictionless nanoscale bearings.

When does such research reach the shop floor? Perhaps not for years. Right now, however, nanotubes are being studied to make a better class of carbon composite, says Susan B. Sinnott, associate professor in the Department of Materials Science and Engineering at the University of Florida. The theory is that they could fit the same applications that other composites, such as fiberglass, dominate today.

"Carbon nanotubes are stiffer and stronger than conventional carbon fibers, and so the feeling is that if we can figure out how to make good carbon composites using carbon nanotubes, the resulting materials will be both stronger and more lightweight than current composites," Sinnott says. "The initial results from laboratory work are promising in this regard. However, carbon nanotubes are currently more expensive than gold by weight; so, before we see car bodies, aircraft, etc., made from composites containing carbon nanotubes, we will have to figure out how to make [them] more cheaply."



Lincoln Brunner

Contributing Writer

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