Saturday, October 29, 2005

Richard Smalley, 1943-2005

Richard Smalley shared the 1996 Nobel Prize in Chemistry with Robert Curl and Harold Kroto for the discovery of buckminsterfullerene, a molecule made from 60 carbon atoms. It was named after Buckmister Fuller, an American architect and inventor who designed the geodesic dome, a structure that looks like the fullerene molecule.

The discovery of buckyballs was significant for many reasons, but a few stand out. First, it represented a new allotrope of carbon (allotrope is a fancy word for the for structural forms an element can assume). Before this, only graphite and diamond were known allotropes. Since then, nanotubes have been discovered, as have higher fullerenes with many more carbon atoms. At the time, however, it wasn't known that elemental carbon could be so diverse.

Second, with the exquisite symmetry of the molecule, the properties were expected to be remarkable, and they are.

Finally, discovering that carbon could form into perfect little sphere-like molecules started people thinking seriously about nanotechnology.

Generally, the discovery of a single molecule gets little press. With the discovery of buckminsterfullerene, Professor Smalley was instrumental in the touching off of a fertile new area of scientific exploration.

Tuesday, October 25, 2005

Nanocars



Jim Tour is one of my favorite scientists. He does a lot of impressive work in the area of molecular electronics and nanoscience, which was my research field as a grad student and post doc. Tour is hard-working as hell, and has a sort of showman's flair for promoting his work that only occasionally spirals off into the hype that the field is infamous for. Now, though, his group has announced a piece of work that is both significant and yet 100% showboat: the nanocar.

The car (pictured in the molecular model above, riding on a street made of gold atoms ) is put together out of fairly straightforward parts, at least from a synthetic chemist's point of view. However, the wheels are fullerene, the 60-atom molecular allotrope of carbon that Tour's colleague at Rice, Richard Smalley, shared a Nobel prize for discovering. Fullerenes are really cool molecules for lots of reasons, but they are a nightmare to modify synthetically. So putting the wheels on this bad boy was a bitch.

Once they got the thing together, they dragged it along a gold surface with the tip of an atomic force microscope, and they showed that it rolls easier along the direction the wheels roll than from side to side. This isn't surprising to anyone who has played with a toy truck; however, in the nano-realm, it is relatively easy to just slide things around on surfaces. The data Tour's group collected suggests that the wheels are really rolling, and the car is not just sliding.

I don't expect GM will be producing these anytime soon. However, people have been hyping nanotechnology for over a decade now, and there have been many pretty pictures made of nanomachines. But there has been precious little real molecular demonstration of all this promise. This work is goofy, yet compelling, and it isn't musing or theory. It's a molecule that you can put in a bottle, and it's all the proof anyone needs that nanotech, though still an infant, has a lot of cool discoveries in store.