Earth & Sky

Will nano help solve 21st century challenges?

Earth & Sky asked Medal of Science winner George Whitesides.

In this century, with a human population of nearly 6.5 billion, Earth has become a human world. No one doubts that we’ll need different kinds of solutions to many of the problems that humans have always faced: food, fuel, water, shelter. Plus we face entirely new problems that our ancestors couldn’t have imagined. National Medal of Science winner George Whitesides is a pioneer in the fields of nanotechnology and nanoscience research. Earth & Sky’s Eleanor Imster spoke to him in September, 2005, asking how nanotechnology can help humanity in the 21st century.

Imster: How will nanotechnology help us deal with 21st century challenges?

Whitesides: My answer would be the following. Unfortunately, we are, as a species, not an object that can be made smaller. We are the size that we are, and so some of the ways that we produce are just intrinsic to our size.

But a lot of our energy consumption is, in a certain sense, optional. That is, we choose to fly for a business meeting to San Francisco. Or we choose to ship goods from place to place.

One of the important jobs nanotechnology will do will be to extend yet further the revolution in information technology that makes it possible to ship information rather than people or things. And that, I think, has the potential to be really quite important for at least energy savings.

Imster: You mean instead of sending a hundred–page document on a truck to the airport, and then on an airplane to another airport, and another truck, it could be sent in a way that’s more energy–efficient?

Whitesides: Yes. In fact, we already do that when we ship an email. Rather than putting a stamp on an envelope and sending the physical thing, we just send the bits.

But there’s no reason for me to fly to San Francisco to go to a business meeting. If the teleconferencing facilities were very good, I would simply sit in front of a TV camera, and for many purposes, that would work just as well. In those kinds of areas, where communication is important, and perhaps where communication doesn’t involve face–to–face contact between people.

I think there can be very substantial savings from information technology that is enabled by electronics that has been enabled by nanotechnology.

Imster: What else? What about about basic human needs, such as food and fresh water? Can nanotech help us there?

Whitesides: I think the answer is yes. They’re going to be a little bit less flashy than information technology.

In agriculture, a major cost is spoilage. Coating fruits and vegetables in such a fashion that one controls the rate at which they ripen – and at which CO2 and ethylene enter and leave the fruit – has a great deal to do with their shelf–life and their preservation. This is one place where nanotechnology might be useful.

In energy production, the production of hydrogen for a hypothetical hydrogen economy and the use of hydrogen in fuel cells both depends on catalysts for hydrogen evolution or oxygen consumption and upon membranes as part of the fuel cell, and these have important components of nanometer–scale structures. So, you can certainly see that in both of those areas, nanotechnology can be important.

On the other hand, a hamburger is a hamburger, and it’s set by our size. There’s no way of “nano–ing” that.

Imster: Nanotechnology will let us create new materials not found in nature. Do you think that humans are smart enough to handle it?

Whitesides: I think we’re smart enough.

Imster: What are some potential problems that might arise?

Whitesides: I think nanotechnology, so far as it’s developing, doesn’t really look as if it has many serious safety issues associated with it. If I had to focus on one safety issue, it would be the toxicology of small particles. If you suspend nanometer–scale materials or dust in the air, and you breathe them, some of those particles might deposit in the lung. There might be toxicology that would be characteristic of, or unique to, nanometer–scale stuff.

We don’t know whether that’s true or not. We, after all, breathe nanometer–scale particles all the time anyway. But there is unusual toxicology associated with asbestos, and it’s just an area that’s not been well enough defined scientifically yet for us to be fully confident about what we’re doing.

However, I should say that this is a kind of risk that we’re very familiar with. It’s an occupational health and safety concern of a sort that we know very well how to handle. It’s just something that needs to be worked through.

At the beginning of nanotechnology, there was a lot of discussion about what was called grey goo The idea was that one would build little machines, and the little machines would build themselves, and there would be exponential growth, and they would crawl out of test tubes and eat the Earth. And this was, I think, from the beginning, pretty much nonsense.

Imster: My sons love it, though.

Whitesides: It’s a neat science fiction, and it’s a good thing to think about. After all, it is true that one has micron–scale things, called bacteria, which do undergo exponential growth.

But the characteristics of bacteria, as an engineered thing, are so many orders of magnitude more sophisticated than anything that we can build right now, that we’re not about to begin to think about building life. And, if we build life, we’re not going to build it out of silicon anyway. So, I just discount this for any foreseeable future completely.

Imster: A year or so ago, people in the science and technology communities were worried that the public would react negatively to nanotechnology. They talked about the public’s reaction to stem cell research and genetically modified, or “GM,” foods as a precedent. So far, that hasn’t seemed to happen . . .

Whitesides: No, and I don’t think it’s likely to. I don’t think that the same issues arise.

Stem cells are controversial for ethical reasons. You have to draw the line between living and non–living, and human and non–human. That’s an ideological and theological issue as much as anything else. So there are people who feel very strongly about that.

GM foods were a much more serious and interesting case. Because arguably the GM foods were introduced with a primary eye toward their commercial relevance. At least in some cases at the very beginning, they were not thought through as carefully as they should have been in terms of impact on human health. And we’ve got perfectly good food. There’s no reason to introduce genetically modified food, unless it does something genuinely beneficial to the consumer: lowers cost or improves transportation or improves nutrition. All of those things are in fact happening, but those benefits were not made very clear to people in the beginning.

With nanotechnology, if I had to pick an area of concern, it’s a second–order concern. One area of technology that will be advanced by nanotechnology is information technology, and particularly electronic memory. As electronic memory becomes smaller and cheaper and faster, it gets to be easier and easier to store information in memory, and perhaps, with future advances, to find it.

For me, that kind of advance in information storage and retrieval does lead to concerns about privacy and individuality in the future. But that is very much a question of how society chooses to use information technology enabled by nanotechnology, rather than the nanotechnology per se.