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Nanotechnologist Richard E. Smalley of Rice University has been awarded the 1996 Nobel Prize in Chemistry for his discovery of buckminsterfullerenes, the complex molecular forms of carbon that resemble geodesic domes designed by architect R. Buckminster Fuller. Named in Fuller's honor, the molecules are commonly called "buckyballs." Fullerenes are formed when vaporized carbon condenses in an atmosphere of inert gas.
The gaseous carbon is obtained, among other means, by directing an intense pulse of laser light at a carbon surface. The released carbon atoms are mixed with a stream of helium gas and combine to form clusters of some few up to hundreds of atoms. The gas is then led into a vacuum chamber where it expands and is cooled to some degrees above absolute zero. The carbon clusters can then be analyzed with mass spectrometry.
While focusing his research on fullerenes and related carbon molecular structures, Smalley has become recognized as a leading researcher in molecularly precise structures. He heads the recently formed Center for Nanoscale Science and Technology (CNST) at Rice.
Smalley spoke at the Foresight Institute's 1995 Nanotechnology Conference, describing the current status of nanotechnology research at Rice. He is scheduled to be the keynote speaker at the 1997 Conference. Also, Update 18 reprinted an interview of Dr. Smalley from the Rice News, Nov. 11, 1993, in which he said, "The idea behind nanotechnology is ultimately, and maybe sometime very soon, to custom design the materials around us atom by atom, much like an architect designs a building. Except now the building materials will be atoms rather than bricks or steel beams. When you design a building, you don't just throw a bunch of stuff down and hope that you get lucky. You design it so the economy, function and beauty is all completely crafted. It is an artificial object that may be artistic, but is also built to have certain functions. The idea of nanotechnology is to learn how to do this on the atomic scale."
In the interview, Smalley also spoke of the importance of computer modeling to nanotechnology. "Much like when you build a bridge. Before you actually construct it, you take this very carefully worked-out design and you submit it to computer calculations to make sure it won't fall down. In the same sense, when we actually get to the point that we start building things on the nanometer scale, we'll have to be able to predict their performance. We will have to describe this object that we're going to build somehow to a computer. And to be able to have that computer chew on the problem and ultimately tell us how it's going to work...We still have a long way to go in calculating the behavior of atoms when they stick together in various structures... However, a lot of progress has been made, an amazing amount, in the past 30 years. And we're getting close."
Today research at Rice's CNST is focused upon a major transition away from the study of fullerene clusters levitated in the gas phase. "The new direction insists that the objects of study survive when exposed to the real world while remaining well defined on the nanometer scale. The object is to develop nanoscale structures and probes for such structures," the CNST Web site declares.
Speaking before the Houston section of the American Society of Chemical Engineers in January 1996, Smalley said, "we are beginning to realize that we can find ways of tricking nature into self assembling carbon into other fullerene-like shapes as well, and that these new materials may well have major practical as well as theoretical significance. In fact, it emerges that buckyball was ( and is) a sort of Rosetta Stone of what we now realize is an infinity of new structures made of carbon one way or another."
One example of the new direction of Smalley's research is the nanowire - a truly metallic electrical conductor only a few nanometers in diameter, but hundreds of microns (and ultimately meters) in length. The objective of Smalley's research group is to "learn how to produce such wires by, effectively, polymerizing carbon into a continuous perfect graphene tube - a giant single fullerene molecule. With dopant metal atoms sealed inside, these fullerene nanowires are expected to have an electrical conductivity similar to copper's, a thermal conductivity about as high as diamond, and a tensile strength about 100 times higher than steel.
"In addition to their wonderful bulk properties, these nanowires will be terrific as tiny probes. Bundles long enough to hold in one's hand, but arranged along their length in a nanoscale array, will provide a direct connection between the macroscopic and nanoscopic worlds."
Smalley has posted on the World Wide Web an article published in Nature magazine describing use of carbon nanotubes as the tip for Scanning Force microscopes (SFMs) and Scanning Tunneling Microscopes (STMs). "Ideally this tip should be of at least the same molecular precision as the nanoscale object to be probed, and it should maintain this perfection reliably in day-to-day practical use not only under high vacuum but also in air and when probing under water," the article says. "Although the best of the currently available tips [for SFM or STM] do at times achieve sub-nanometer resolution, they seldom survive a direct 'tip crash' with the surface, and it is rarely clear just what the atomic configuration of the tip actually is when the image is taken. Carbon nanotubes, particularly those which are effectively fullerenes of macroscopic length in one dimension but still intrinsically nanoscopic with molecular perfection in the other two dimensions, may offer the ultimate solution to this tip problem." Smalley's article reports initial successes in using individual carbon nanotubes several microns in length as probe tips in SFM and STM.
Smalley and colleagues also are pursuing research related to carbon nanotubes as novel nanoscale materials and device structures. "Defect-free nanotubes that are essentially giant, linear fullerenes are expected to have spectacular mechanical properties, as well as electronic and magnetic properties which are in principle tunable by varying the diameter, number of concentric shells and chirality. Further progress toward practical materials will require eliminating defects and other reaction products (such as amorphous carbon and catalyst particles), maximizing the nanotube yield, and synthetic control of tube diameter, length, chirality, and number of concentric shells," he writes.
Smalley has vigorously advanced his view that nanotechnology must be achieved to support the planet's rapidly growing population. For example, in a speech delivered in late 1995 to the Board of Trustees of the University of Dallas, Smalley concluded, "We've got to learn how to build machines, materials, and devices with the ultimate finesse that life has always used: atom by atom, on the same nanometer scale as the machinery in living cells. But now we've got to learn howto extend this now to the dry world. We need to develop nanotechnologyboth on the wet and dry sides. We need it urgently to get through these next 50 years. It will be a challenge. But, I am confident we will succeed." |