If you listen to the boffins in the lab coats, there are few problems that nanotechnology-once it comes into its own-will not be able to solve.
U of T materials scientist Dr. Uwe Erb, however, is less sanguine. “The fastest-growing letter in the dictionary is n,” he said. “It’s because of all the nano entries that people create.” Researchers, he said, are rather keen to tack the prefix nano to their work, even when the objects involved are sized in the micro-range-a millionth of a meter-rather than the nano-a billionth.
“One has to be careful, because a lot of it is hype,” Erb warned. The field with the most potential, he said, is that of nanomaterials.
Indeed, the technology journal EE Times has estimated that by 2015, the world market for nanomaterials could grow to US$340 billion a year, with electronic applications of nanotechnology second, at US$300 billion. Nanotech tools, by contrast, which have both awed and appalled the public with visions of nanobots, may have a market of only US$20 billion a year.
Nanomaterials may have a head start, but that is perhaps because scientists have been working at them for some time. Erb has been researching ways to increase the strength of metals since coming to Canada in 1983, after studying in Germany under one of the pioneers in the field of nanometals.
The way to increase the strength of metals, they realized, was by shrinking the average size of the grains in a metal. Normally, the size of these grains is in the micrometer scale, but reducing their size to the nanometer scale is the key to making metals stronger, lighter and more flexible. But as grain size shrinks, a greater proportion of the atoms in the metal find themselves at the border between grains-where they do more to keep a material together than elsewhere.
The way to produce materials with such small grain sizes is through a process called electroplating. A negative charge is applied to the material that will be coated, which is then immersed in a solution containing positive ions of the nanometal. The negatively-charged material attracts positively charged ions, which coat the metal in a thin layer.
The average grain size in these coatings is only six nanometers, noted Erb. “We talked of these always as nanocrystalline materials. We didn’t use the term nanotechnology,” he added.
Nanocrystalline materials were first applied in 1994, to solve a problem with the steam generators at Pickering’s nuclear power plant. The pipes carrying heavy water from the reactors had become corroded, and needed replacement. But instead of rebuilding the steam generator, which would have cost $100 million and shut down the plant for up to a year and a half, Ontario Hydro called on Erb’s company, Nanometals Corp, to come up with a solution. They did so by creating an electrosleeve inside the damaged tubes. “You electrodeposit a tube inside another tube,” Erb explained.
Erb believes that the alloying together of metals to create new materials, as humans have done for thousands of years, has reached its limit. “We have … exhausted the possibilities with the elements we have on the periodic table,” said Erb. But now, the strength of metals can be increased by “a factor of five to ten times stronger without doing anything else,” according to Erb.
And applications of such materials are starting to appear on the market. Last month, US sports equipment manufacturer Wilson announced that next season it will start selling golf clubs that incorporate electroplated nanometals in their shafts. This will make the clubs even lighter, enabling golfers to swing them faster, thus adding precious yards to their drives.
The nanometals are supplied by PowerMetal Technologies Inc, using know-how developed by Toronto-based Integran Technologies Inc. Integran’s CEO, Gino Palumbo, said the deal with Wilson is the biggest involving nanotechnology in sports equipment yet. Besides that though, he noted, there is little nanotech on the market. “There really isn’t a lot out there in terms of products,” Palumbo said. “There’s a lot of sizzle and no steak.”
The key, he added, is to target applications where cost is no object, such as the biomedical or defense industries-or sports equipment. “You have to look at where folks will pay a premium for materials,” said Palumbo. “People are willing to pay literally thousands of dollars a pound for material, just to have the latest and greatest bike or golf club or fishing pole.”
