TR: Of course, none of those shorter-term applications really fulfill the huge promise of nanotubes, do they? Such as acting as an electrical conductor in a biological environment?
SMALLEY: And what I was talking about before was only on the wet/dry interface. Then you get back to the dry side. There is a “lunatic fringe” of the nanotube world that we haven’t talked about yet. Over the next year there will be in my lab, and I suspect in many around the world, a big push to develop means of spinning continuous fibers-macroscopic fibers-of nanotubes with a high degree of orientation [the nanotubes would be aligned like uncooked spaghetti in a box]. I think that’s going to be successful, and it will be something special.In one direction nanotubes are the strongest damn thing you’ll ever make in the universe and are excellent electrical conductors; in the other [perpendicular] direction, they’re floppy, and the electrical conductivity is quite poor. So, in materials where you want electrical conduction, you care about how well the nanotubes are aligned. I believe it is going to be possible to make continuous fibers of nanotubes in an efficient spinning process that will have the tubes all aligned. I wouldn’t call that the lunatic fringe; I think it’s going to happen. But now let’s talk about the really lunatic extreme. What if these spun fibers were, instead of a micrometer long, a kilometer long?
TR: In theory you could make nanotube fibers a kilometer long?
SMALLEY: In theory you can make them to Alpha Centauri. What would be the strength of a long fiber? You would have the strongest damn thing ever made in the universe. Can we ever make that? And what good would it be? If you could make it cheaply and a continuous length, you could make the longest suspension bridge you ever heard about, elevators in space. But “buckycables” would also be terrific conductors of electricity. It is the logical replacement for all power transmission cables in the world. That’s at the lunatic fringe, but I can say that because I’m an advocate of it.
TR: As you know, there has been a growing effort to use organic molecules as tiny switches in nanoelectronic devices (see “Molecular Computing,” TR May/June 2000). What role do you expect that nanotubes will play in molecular electronics?
SMALLEY: In the long term, it seems they must figure in-because they’re nano and they conduct electricity. Whether or not they’ll figure into nanoelectronic gadgetry in the next decade, I don’t think anyone is smart enough to know. In fact, no one is smart enough to know if there will be any nanoelectronic gadgetry in the next decade. But most people agree that if you had to pick the electrical conductor in nanoelectronics it will eventually be a nanotube. We’ll just have to stay tuned to see how quickly that happens.
TR: For now, even something as simple as putting a nanotube where you want it is still a challenge, isn’t it?
SMALLEY: We are really children, not even children, babies, in understanding how nanotubes work.
TR: Still, I was thinking how quickly the field of nanotech has moved. When I interviewed you a few years ago, we talked a lot about the hype surrounding nanotechnology. Now, with more and more serious scientists getting involved, it seems to have moved beyond that.
SMALLEY: That was the key factor, serious scientists getting involved that are far removed from “nanobots” [nanoscale robots figure in many speculative visions of nanotech]. We haven’t quite completed the task of “de-nanobotting” the field. But the main point is that nanotechnology is so important that we don’t want it to be associated with just nanobots. Whether or not they can ever happen is another issue, but there’s a so much broader reality to nanotechnology-and in ways a much more interesting one.