It’s a Nano World
By Patrick McDonagh
PHOTOS: OWEN EGAN
Look – nano-pants are 30% off at the Bay,” says Peter Grütter, waving a catalogue advertising garments coated with a “nano-material” purporting to resist dirt – “but I don’t know if it’s really nano,” he says. These days, the prefix draws a lot of attention. “The hype is so high that people are putting ‘nano’ on all sorts of things. We have to distinguish the real nanotechnology from nano-pretenders.” Grütter, a professor in the Physics department, is the real thing, one of a core of McGill researchers exploring the various manifestations and applications of nanoscience and nanotechnology.
High-tech apparel is by no means the only nanotechnology application out there. Recently, Hewlett Packard’s television advertisements have drawn attention to their research into the use of nanotechnology in the creation of faster, more precise printers. The company is also at work on a computer chip using molecules as transistors; eventually, such a chip could hold a billion transistors, whereas today’s fit no more than a measly 50 million.
In other realms, nanotechnology operations are already in action – for instance, in creating stronger, lighter metal alloys for use in automobiles and aircraft. Biomedical applications are also in the works, from systems that could deliver drugs to the body more effectively to those that facilitate the use of prosthetic implants. Indeed, hardly a research area exists which doesn’t have the potential to incorporate nanotechnology applications: from energy to agriculture to pharmaceuticals, nanotechnology research has been drawing the bright young minds.
What is Nano?
As a result, what constitutes the truly nanotechnological can be difficult to pin down. “If you talk to one hundred people in nano research, you’ll get two hundred definitions,” says Grütter – who obligingly offers two. First, the materials being dealt with must be less than a micrometre – itself pretty small, at one-millionth of a metre (there are a thousand nanometres in a micrometre, and a billion in a metre). In fact, nanostructures are usually much smaller than the 999-nanometre cut-off point: the structures are often built from few enough atoms that they can be counted individually.
“Secondly,” says Grütter, “a nanosystem has to have properties that are different because of its size. For example, even at the micrometre level, electrical conductivity through a wire follows classical principles. But if we shrink the wire to a few nanometres in diameter, conductivity changes. Classical laws no longer apply, quantum mechanical effects kick in, and things become weird, strange or interesting, depending on your point of view,” he explains. At this point, electronics becomes nanoelectronics, which is creating a buzz thanks to its potential application in smaller, faster computer systems.
Work Wins Acclaim
Grütter’s nano research has followed a number of paths, but much of his work involves designing and building the sophisticated microscopes that enable scientists to watch clearly what atoms are up to in nanostructures. Once the tiny molecules can be visualized, they can be experimented upon. He has also carried out research into regulating conductivity at the molecular level, and has collaborated with medical researchers from the McGill University Health Centre to understand the processes through which neurons conduct the impulses that enable us to feel pain.
His innovative and energetic work has won him plenty of acclaim, including a 2001 Steacie Fellowship, one of the country’s top science and engineering prizes awarded by the Natural Sciences and Engineering Research Council (NSERC), and he has been the nation’s nano-chief since June 2002, when he was named Research Director of the NSERC Nano Innovation Platform and placed in charge of coordinating a national strategy for nano research. The federal government is serious about increasing nanotechnology in Canada, directing over $150 million in recent years to building a national research infrastructure. And Nano-Québec, established in 2001, will do the same thing provincially, thanks to $15 million committed to it by the provincial government.
McGill is also in the process of developing a nano strategy and has quickly become the top place in Canada for nano research. Over a year ago, Grütter and other McGill researchers across disciplines – including physics, chemistry, life sciences, chemical engineering, and mining, metals and materials engineering – joined to create the McGill Institute for Advanced Materials (MIAM).
“The term ‘advanced materials’ covers a wide range,” says Bruce Lennox, Chair of Chemistry. “It really designates an approach to materials as much as the materials themselves.” So an “advanced material” could be an innovative metal alloy, a plastic composite, or even a new form of concrete. “Basically, it involves looking at performance characteristics of a material and trying to enhance them,” says Lennox. Nanotechnology provides an important way to enhance materials, and is thus expected to assume an important part of MIAM’s mandate.
“MIAM is a formalization of a community that already existed here,” says Lennox. “A lot of material research was going on at McGill, but was isolated in departments.” MIAM addresses this isolation by bringing together scientists from different areas to share ideas and, ultimately, collaborate on projects; through its association with Nano-Québec, MIAM will also lead to further exchange with researchers around the province.
New Nanotools Facility
Thanks to a Canada Foundation for Innovation grant from the federal government and support from the provincial government and other sponsors, MIAM has a newly constructed $9 million nanotools centre, which opened officially in November. The facility includes a “clean room” filled with the high-tech machines needed to make nanomaterials – “clean” because it is constructed to eliminate unwieldy dust particles that might crush or otherwise impede those tiny objects of research. “It’s a 21st-century machine shop,” says Lennox. “These tools are pushing all the limits.”
MIAM researchers also have a state-of-the-art microscope that can image and characterize individual atoms, and a supercomputer formed by a cluster of over 780 processors, with the power to run complex simulations.
Andrew Kirk, a professor in the Department of Electrical and Computer Engineering, is the co-director of the microfabrication lab in the nanotools facility. His research in photonics – the science of working with the energy in light and radiant energy, or the photons – is concerned with controlling and routing optical signals for telecommunications networks and high-speed computers.
“In order to do that,” says Kirk, “we are trying to make very compact systems, which can be thought of as optical integrated circuits and analogous to electronic integrated circuits. To make these as compact and efficient as possible we need to be able to pattern structures which are the same scale as the wavelength of the light that we are using, which is of the order of one micron in the glass and silicon that we use. We need to be able to control the size of these structures with an accuracy of tens of nanometres, and so the new facility is very important.”
Kirk says, in regard to basic science, “The facility allows us to collaborate with researchers in physics and chemistry in a way that was not previously possible at McGill, since we can now work together to make devices that solve real engineering problems based on new scientific principles.” And he foresees links with a wide range of departments throughout the Faculty of Engineering and in biomedical research as well. “Before, we could not make the types of devices that would allow us to contribute effectively in the biomedical area, and it would not have been practical to get prototypes made elsewhere, due to the expense and the time delay.”
Both Grütter and Lennox argue that nanotechnology has the potential to be a true renaissance science, developing new hybrid areas of research. Lennox’s work in chemistry could have important applications in the life sciences, for instance. He takes elemental gold and reduces it, through chemical treatment, to spheres called quantum dots, about two nanometres in diameter. “These quantum dots in solution are an intense red, with properties completely different from gold,” he explains. The dot has diamond-like facets, and chemicals can be deposited on this surface, which then change the dot’s colour. Lennox is hoping to use this quality to develop a biosensor system, in which colour change could be used to indicate the presence of certain molecules – say, a certain type of DNA – in a solution.
But not all nano research focuses on tiny things alone. “Bulk nanomaterials” is how Robin Drew, Chair of Mining, Metals and Materials Engineering, describes one of his areas of research. “If you have better control at a nano-structural level, you can have more control over a structure’s properties,” he says. Much traditional metallurgy and materials science has involved working in the nano range, but without the trendy moniker. Heat treatment to strengthen aluminum alloys was discovered at the turn of the last century, but for years people didn’t understand the phenomenon, although they knew it worked.
“The science behind it started in the 1950s and ’60s,” explains Drew, “but even then the processes involved manipulating atoms and then hoping that nature would produce what was wanted.” Those days of trial and error may soon be numbered, as atomic probe technologies allow researchers to actually see atoms, map their configuration and dispersal, and understand what they are doing. “This way, when we make changes to the process, we can analyze their consequences. Then we can correlate this information with the atomic properties we’ve observed and manipulate atoms to control properties – such as the strength of alloys.”
Big Benefits from Tiny Technology
Carbon nanotubes are another favoured nano material. These filaments of carbon are several nanometres in diameter, with lengths reaching into the micrometre range. Discovered in 1991, their conductive properties make them extremely useful, as they can be used as “on-off” gates, a basic element in computer systems. They are also ten times stronger than steel, and Drew has collaborated with Raynald Gauvin, also in Mining, Metals and Materials Engineering, to explore their applications in magnesium and aluminum alloys for use in everything from automobile bumpers to airplane fuselages. So far, though, many of the challenges are very basic.
“One problem is to make nanotubes at a competitive price,” says Gauvin. The current fabrication process involves plenty of waste carbon with a 0.2% nanotube output, a ratio Gauvin would like to see increased tenfold. “Then, we have to remove the nanotubes from the rest of the carbon and clean them of residue.” Once extracted and spruced up, the nanotubes must be integrated into a metal to strengthen it – also no easy task. Still, if Drew and Gauvin are successful, their research could have profound consequences for industry in Quebec, which produces one-tenth of the world’s aluminum, but ships most of it elsewhere for processing. “We have a strong aerospace industry in Montreal, and Bombardier airplanes are mostly aluminum,” says Gauvin. “The economy will benefit if we could develop an industry fabricating aluminum with carbon nanotubes here.”
Health care may also benefit from nano research. Calcium phosphate mineralization in the body can be desirable – we need it for bones and teeth – or detrimental, as it also is the process behind kidney stones and arterial sclerosis (the hardening of coronary arteries). The crystals formed by mineralization are two or three nanometres thick and a few dozen nanometres long, and their growth is controlled by segments of proteins, called peptides, which bind to their surface. “We’re trying to understand how these organic proteins and inorganic crystals interact at the nano level,” says Professor Marc McKee, who is cross-appointed in the Faculties of Medicine and Dentistry, where he is Associate Dean, Research. “Then we can try to cure mineral defects in the skeleton and teeth, and perhaps block crystal growth in pathologies like kidney stones.”
Other research involves creating bioactive advanced materials like biochips, biosensors and other biomaterials which could be used for tissue replacement, such as with hip implants. Cells have patterns, tiny nanostructures, that are characteristic of them, and they can recognize these same patterns on other cells – a process known as bio-recognition. “It is possible to inscribe these nanostructure patterns from a cell onto a biomaterial’s surface,” says McKee. In effect, then, nanotechnology will allow scientists to create biomaterials whose surfaces mimic the body’s cell structures. “Cells will recognize these patterns, which could then result in faster acceptance and smoother integration of the biomaterial into the body,” he explains.
Nano is Big with Students
Nanotechnology’s diverse potential is attracting students from engineering, science and life sciences to McGill’s senior undergraduate class in nano research, the only one of its kind in Canada. As befits the topic’s multidisciplinary nature, the course is team-taught by Lennox, Grütter and other nano experts from science and engineering. While the course introduces some of nanotechnology’s basic principles, it has an additional objective, which Lennox stresses in the opening class: to educate students to sift through the hype, propaganda and hysteria that occasionally risk overwhelming the field.
Mass misunderstanding of nanotechnology is a serious threat to research, says Grütter. Often, scientists themselves are to blame. “If you shout loud enough that you’ll change the way the world will work, eventually people will start to believe you. And then you have little control over expectations.” One result is that a number of debates have erupted around nano research, and while some concerns are serious, others are ludicrous. “A lot of discussions about ethics and nanotechnology have focused on things which are not even scientifically possible,” he says.
The strongest case in point is the “grey goo” anxiety. Eric Drexler, of the Foresight Institute – “which is more cult than science,” says Grütter – hypothesized in his 1986 book Engines of Creation that self-replicating nano-robots could assemble items – a footstool, for example, or maybe a sandwich – atom by atom, presumably like a Star Trek replicator vending machine. “The idea was total baloney,” says Grütter, “and contradicts lots of known laws of physics and chemistry.”
Drexler also hypothesized that these nano-robots could get out of control, replicating continually and forming an ever-increasing “grey goo” that could absorb other materials. “No one has ever explained how any of this might be possible,” says Lennox. But the idea has proven media-friendly, despite – or perhaps because of – its echoes of medieval alchemy, and its “Blob That Eats the World” script has since created anxiety among the credulous.
Don’t Believe the Hype
Apocalyptic science fiction is not the only threat to nano research. So is unsubstantiated hype, occasionally from scientists or organizations pumping for research dollars or good PR. “Statements like ‘Nano is going to make health care unrecognizable in ten years’ are garbage,” Grütter stresses. As Marc McKee’s research demonstrates, nano components are likely to appear in health care applications, but their presence will probably be quite subtle. “Society, and politicians in particular, develop expectations, and a few years down the road may not be willing to wait for us to deliver on them,” says Grutter. “And so we lose credibility.”
In exchange for the hype, Grütter offers a sober counter-prediction: “Nanotechnology will not necessarily stimulate a huge technological revolution, the way silicon has, although it may influence aspects of everyday life 30 years from now. Instead, it will probably be incorporated into other industries.” So aluminum alloys will be stronger, medical implants will be accepted more readily, and computers will be smaller and faster. And, of course, coatings for textiles, such as the Bay’s nano-pants, are likely applications. Cosmetics giant L’Oréal is already the third biggest patent-holder in the world of nano, applying the technology in creating such products as hypoallergenic makeup and long-lasting sunscreen.
“Nano materials are already out there,” Grütter says. But the future looks less like the science fiction scenarios painted by the over-enthused and the anxious. Nano materials are likely to seem fairly mundane, once we get to know them. And we may be wearing them already.