How long have you been involved in nanotechnology?

I have a center at Georgia Tech for computational materials science and we have activity in several areas, with an emphasis on computer simulation and modeling of materials properties in the nanoscale. Our interest in the properties of materials on the nanoscale started some 20 years ago. For a while it was regarded mainly as a branch of theoretical research, then it became possible experimentally to actually produce these materials as well as observe and detect them.

I’ll give you an example. Take gold and make a wire out of it. When it is in microscopic size — microns or millimeters, it doesn’t matter — you can conduct electricity through it and measure the resistance of this wire.

But when you reduce the diameter of this wire to the nanoscale, maybe five to 10 atoms along the diameter, it conducts electricity in a completely different way. It’s still gold; you didn’t make a new material, but it exhibits completely new behavior because of its smallness.

So nanotechnology provides an approach for developing new materials?

Nanoscience is the science of the new properties that appear when materials are reduced to the limits of the nanoscale.

Part of it is devoted to the making of new materials, but it relies mostly on the fact that when one goes to small sizes, the properties of materials change. In other words, small is different. So instead of changing the chemical composition of a material, here you have a new parameter — namely size — that by itself changes the property of the material, although it is made of the same chemical element.

It has been speculated that intelligent nanobots could one day be injected into the human bloodstream to perform surgery or even serve as weapons. On the opposite end are the doomsayers who contend that nanorobots pose a potential threat. What do you think?

I must tell you that I dislike the word "nanorobots." This implies something artificial, you know? And because of science fiction, it also implies something that is kind of magical and people go and extrapolate that into the idea of robots taking over the world.

There are even people who go around and talk about robots that will make factories to make other robots and so on. This is utter nonsense.

Cows and camels don’t fly, gorillas don’t swim and nanorobots don’t exist. Nobody has ever built a nanobot. Of course one can fabricate certain nanoscale structures, and this has been demonstrated. However, a robot implies an autonomous structure. The whole proposal of building nanorobots that would operate independently, and with self-replicating capabilities, is misguided conceptually, methodologically and practically.

All that said, there are certain machines, mechanical instruments, that are going to be built and are being built on the nanoscale. I’d rather call them nanomachines.

Could a nanomachine be mechanical?

Yes, you could have mechanical devices, though it depends on how you define mechanical. I suppose if it has a gear wheel or if it rotates or has moving parts, it qualifies as something that has a mechanical aspect to it.

What might a nanomachine look like, and how would it be used?

One application people talk about would be used for targeted drug delivery. You would need nanostructures that could identify malignant cells, be able to dock with them and then there must be some kind of mechanism for pushing the drug out into the cell.

So, if you fill these jets with the right drug, you can structure them into the nanomachines and they will deliver the drug to cancer cells selectively, without killing healthy cells or spreading the debris of the malignant ones. This may serve also as a method for targeted injection of genetic materials into cells — that is, "gene nanoartillery."

What about self-assembly for nanomachines and structures? Is that a scientific possibility or just science fiction?

There are materials called C-60 or carbon nanotubes. You take two graphite rods and put them a certain distance apart, then apply high voltage between them to burn the rods. This arc discharge process produces little soccer balls made of 60 carbon atoms or elongated structures called carbon nanotubes.

We already have a name for chemical machines that produce chemicals: enzymes. An enzyme is basically a nanoscale machine, and it works wonderfully.

I believe that if we can harness nature in a useful way to make nanoscale materials, this is the future of nanotechnology because it is really the leastexpensive way of making materials — let nature assemble it. But we need also to remember that biology evolved in the service of biology. In other words, the mission of biology is to support life processes, not necessarily technological ones. So in order to make use of nature’s ability to self-select and self-assemble, we have to understand these processes and employ or mimic nature in a creative and compatible way.

Some say that nanotechnology has the potential to spark a kind of industrial revolution. Do you agree?

People say this is the nanotechnology revolution. It will be like an industrial revolution. Well, this might happen and I believe that sometime it will become a tremendous boon to society. But one thing should be kept in mind. This technological revolution will depend tremendously on science.

Why? Because we do not know what these materials do when we take them to the nano size, and we don’t have the blueprints to make devices. It’s not a simple matter of scaling down. You have to redesign everything because the materials behave differently, and you need first to discover and understand how they behave and under what conditions "small is different." Then you may be able to harness these nanoscale materials and their novel properties and launch the so-much-talked-about nanotechnological revolution.

©2005 Georgia Tech Alumni Association