November 1998

Nanotech: Art of the Possible

The potential is mindboggling--from wristwatch-sized reference libraries to submarines in your blood. But there's plenty of hype, too. A Pioneer in the field sorts the feasible from the fictional.

By Technology Review

In George M. Whitesides' line of work things are measured in nanometers. A nanometer is one-billionth of a meter, and to get a sense of how small that is, forget about analogies to the width of a human hair or the head of a pin. The "nanoscale" has nothing to do with familiar items. You need to think about a place where objects-including the devices being worked on by Whitesides and others-are only slightly larger than atoms.

Building things on that scale is called nanotechnology. It's a rapidly developing field with immense potential; tiny devices could revolutionize computing, information storage, communications and any number of unforeseen areas. But it's also an area prone to overblown promises, with speculation about nanomachines that are more likely to be found in Star Trek than in a laboratory.

A distinguished chemist and materials scientist, Whitesides has been exploring this very small world for years. After nearly 20 years at MIT, Whitesides joined Harvard University's chemistry department in 1982. The Harvard researcher has provided micro- and nanofabrication with some of its most useful construction techniques. But Whitesides also keeps a well-trained reality check on the nano world. Despite his obvious enthusiasm for the field, he's intent on defining what is, and what isn't, going to be possible.

TR Senior Editor David Rotman recently visited Whitesides, Mallinckrodt Professor of Chemistry at Harvard, at his Cambridge office to sort out fact from science fiction in nanotechnology.

TR: Let's start with a basic question. Just how small qualifies for nanotechnology?
WHITESIDES: The standard definition is functional structures that have feature sizes less than 100 nanometers, but I think the number probably should be 50 nanometers or less.

TR: Why is nanotechnology so intriguing?
WHITESIDES: It's an extension of microtechnology. And microtechnology is the basis of making computer components, and that's a very big deal. Microtechnology has gotten along for years on the idea that making things smaller brings benefits-they're less expensive, you get more portability and more performance per dollar. The idea is that since "smaller" has worked with microelectronics, you can continue that trend beyond the current sizes in microelectronics, and this shrinking gets you into the world called "nano."

TR: What specific technologies could come out of such work?
WHITESIDES: A good example is information storage. Right now the size of a spot on a CD disk is on the order of 10 square micrometers. People, particularly the IBM folks, have made CD equivalents that use pits on a spinning disk but the pits are now 50 nanometers in size. You could get, in something the size of a wristwatch, the equivalent of maybe 1,000 CDs. That starts approaching a fraction of the reference library that you need for your life. That raises interesting questions: What happens when you're able to put all of the information you need for some major fraction of your life on your wristwatch, rather than actually having to learn it? It's one of those ideas that shifts a little bit the notion of how a life should be led. You can take those ideas and extrapolate them. You put a micro or global positioning system on your wristwatch, so you know where you are. You could have the capability to locate yourself, to do computations, to use information, to communicate.