Nanotechnology and Harnessing 'Micro-Oxen' A paper published this week in the Proceedings of the National Academy of Sciences describes a way to use tiny algae as beasts of burden, hitching tiny beads to them like loads attached to a team of "micro-oxen."
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Nanotechnology and Harnessing 'Micro-Oxen'

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Nanotechnology and Harnessing 'Micro-Oxen'

Nanotechnology and Harnessing 'Micro-Oxen'

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Now turning from very large animals to teeny, tiny, little, very small organisms. Imagine wanting to move a very small load around, a microscopic cargo. You have this cargo that's very microscopic and you want to move it around. You could try picking it up with the tweezers. Maybe you could poke it with a really sharp, tiny little glass needle, a pin like that. But then, you know, you're a scientist, and that's not a very elegant way to try to do things, and probably wouldn't work a lot of the time.

Well, there is a much more elegant way of doing it, and maybe you can find some way to--maybe you can put a little outboard motor on that object, like you would in the river, right? You know, a little tugboat or something, a tiny motor, attach it to the package, maybe even some kind of sensor to let you point the package in the right direction once you got that little tugboat attached to it and you can move it around.

Well, writing in the Proceedings of the National Academy of Sciences, a group of researchers at Harvard described a way to do just that, and using a tiny, one-celled algae as sort of the tugboat or the beast of burden here. They use surface chemistry to attach their loads, and in this case they were polystyrene beads, to the outside of microscopic algae cells. The algae swim. They beat their flagella in a motion reminiscent of the breaststroke, and by shining a light on the swimming cells, the researchers can guide them back and forth to where they want them to do--kind of really interesting.

Joining me now to talk about that work and other experiments at the edge of chemistry, biology and nanotechnology is George Whitesides. He's the Woodford L. and Ann A. Flowers University Professor in the department of chemistry and chemical biology at Harvard in Cambridge. He's a National Science Medal winner and one of the authors of that paper. He's also co-author of the book "Surface of Things," and he joins me now by phone from Harvard.


Dr. GEORGE WHITESIDES (Harvard University): Thank you very much. Glad to be here.

FLATOW: You know, who came up with this idea? (Laughs) It sounds very interesting.

Dr. WHITESIDES: Well, the idea of how one develops a new technology, nanotechnology, is pretty complicated. Ideas come from everywhere.

FLATOW: Right.

Dr. WHITESIDES: And in this particular case, one of the things one wants to do when one thinks about building a technology is to understand how to move things.

FLATOW: Right.

Dr. WHITESIDES: And whatever `things' can be is a flexible definition, so that we started with a thing that was simply a model, a little bead. There's no particular reason to move that, per se, but one hopes that more interesting things will come of it.

FLATOW: Mm-hmm. So this is a proof-of-concept demonstration?

Dr. WHITESIDES: It's a proof of concept. And so then the question is, do you try to build a motor, something that looks like a small submarine or, as you say, an outboard motor, or do you try to use something which is alive and biological? And we took the option in this case--and I think in many circumstances it will be the right option--of trying to work with biology, as biology has, of course, had lots and lots of practice in working with small things and moving them around.

FLATOW: And how are you able to guide where you could get the algae to go where you want it to go?

Dr. WHITESIDES: Well, an algae is basically a plant. It's photosynthetic, so that it's very much in the interest of the algae to go to where the light level is right. And they're very clever. I mean, I have to say every time that I look into the strategies that simple organisms, single-cell organisms use to sense their environment, I'm just amazed at the sophistication of the strategy. But this single-celled organism, this modal plant has a method of finding where the light level is just right. If it's dark, it can't photosynthesize, so it can't make the chemicals it needs to run its metabolism. And probably if the light is too bright, then it's sunburned. I don't know what the problem is, but it doesn't like it too bright or too dark, it likes it just right. So what we can arrange to do is to turn on lights in various parts of our device, and the organism will then move toward that light if it perceives that light to be of the right intensity for it to do its photosynthesis.

FLATOW: And by the intensity, it goes in different places...

Dr. WHITESIDES: In the intensity, it goes in different places.


Dr. WHITESIDES: But it's--you know, think of it as going to where the smell is best.

FLATOW: Right. And what use can you make of this now you know how to hook up the algae to, you know, a cargo?

Dr. WHITESIDES: As I said, it's a model.


Dr. WHITESIDES: And so the question is, where would one want to have a small organism pulling a load around? And I think the answer to that remains to be seen. The first thing to do is just to show that it can be done. And that was what we did. And the notion in that is to make the case that you can get it to pick up the load, drop off the load, and go in some direction. But I could imagine, for example, that if I had a large body of water that I wanted to survey for something, I wanted to see if there were toxins in it or I wanted to see what might be there in the way of nutrients or whatever, I could take these organisms and drop them into the pond, into the large body of water and let them swim around, and then turn on a light, maybe at night, and they should come toward it. So it would be a hunt-and-fetch kind of strategy.

FLATOW: Right.

1 (800) 989-8255. We're talking with George Whitesides on TALK OF THE NATION/SCIENCE FRIDAY from NPR News.

Of course you're an expert on surfaces. Did you have to discover something new about surfaces of algae to get these to turn into a tugboat here?

Dr. WHITESIDES: I think we had to--we being the postdoctoral fellow, Doug Weibel, who did the work; I don't do anything, I sit at my desk and other people do the work. So anyway, Doug did the work. And he took advantage of surface chemistry, what binds to what on the surface of the algae, in a very clever way. I think that the basic processes had been known before, but the surface of the algae is sticky in a particular kind of way, in a molecular way, and one can find ways of taking advantage of that. Getting the load, the sphere to stick was one thing. Getting the load to fall off afterwards was, I think, a little bit more clever. But even there it was known chemistry. What we ended up doing was to connect the load to the algae by a linker that itself broke when one shined light on it. But it has to be the right kind of light. And we were, I have to say, a little bit surprised that we could get the link to cleave without at the same time doing any apparent damage to the algae.

FLATOW: You touched on it before a little bit, but this sort of seems to be a little different approach to nanotechnology engineering, where you're using biological objects or already existing biological living forms as opposed to someone who might try--and we've seen this over the past years--build little mechanical motors.

Dr. WHITESIDES: Right. There's an interesting controversy in nanotechnology as to what the strategy is. And at the beginning of nanotechnology, there was an idea that the way to think about nanotech was to look around you and see things that were submarines or automobiles or motors, devices that work in a scale that we're familiar with, and then make them very, very small. And very, very small means change their size by about a factor of a million or something like that, maybe more. The trouble with that is that I think one can make pretty convincing arguments that most of those sorts of ideas simply won't work for one or another reason. And that's both, you know, a limitation, but also in some sense is a comfort because there was also, as you well know, a concern that one might be able to build small machines, nano-scale machines, that would, among other miraculous things, replicate themselves and then, in replicating themselves, begin to eat their environment. And the fact that you can't either make small motors or probably make small replicators makes the subject something which is of a different character than people were, I think, a little worried about.

But if you look at biology, we are, after all, composed of cells that are a few microns across and the cell is filled with what I'll loosely call machinery, components which are some nanometers across. So nature's had a really remarkable...

FLATOW: Head start.

Dr. WHITESIDES: ...set of accomplishments in building these things.


Dr. Whitesides, stay with us. We're going to take a short break...


FLATOW: ...and come back and take some questions and talk more about your views on nanotechnology and the conflicts that go on there and the potential for the future. So stay with us. We'll be right back after this break.

I'm Ira Flatow. This is TALK OF THE NATION/SCIENCE FRIDAY from NPR News.


FLATOW: You're listening to TALK OF THE NATION/SCIENCE FRIDAY. I am Ira Flatow.

We're talking this hour about chemistry, nanotechnology and wherever else our language and dialogue takes us. I'm talking with George Whitesides, Woodford L. and Ann A. Flowers University professor in the department of chemistry and chemical biology at Harvard University in Cambridge. Want to get those donors right. Our number, 1 (800) 989-8255.

And when I rudely interrupted Dr. Whitesides, he was talking about using these tiny little microorganisms help us do work for us instead of trying to build them mechanically. And is that where you see the advantage here?

Dr. WHITESIDES: Well, nature's been at it for a while...


Dr. WHITESIDES: ...and has some pretty clever solutions, much, much more clever than the ones that we can come up with right now. So why not use them? It's the engineering approach, but I think it can be made to work.

FLATOW: So what about these people who are trying drag molecules one at a time, you know, around and build things like that? You're not a fan of that?

Dr. WHITESIDES: I think that there are different flavors of that. There has been some truly spectacular work done in using an atomic force microscope, basically a needle with a very sharp tip, to shove atoms around on surfaces. And I think it's spectacular work and in due course is likely to be good for something in terms of manipulating surfaces at the atomic level. But then the idea of actually building very small mechanical motors has a lot of problems with it. Friction gets to be much more important at small scales. It's not clear how you power them. I mean, it's just--things don't scale from large to small very well. And biology is full of rotary motors, it's full of linear motors, it's full of pumps, it does all kinds of amazing things, and one might as well use those devices.

FLATOW: What about--we're hearing more and more about self-assembling.

Dr. WHITESIDES: Ah, yes.

FLATOW: I know you're interested in that.

Dr. WHITESIDES: Self-assembly, yes. Self-assembly is the process by which some complex system puts itself together. The pieces choose to come together just of their own volition. You don't have to reach in and cause them to do it. And there are lots of examples of self-assembly that we're all familiar with. Basically, every crystal, that little piece of sugar--the molecules of sugar have come together and formed a nice regular structure. So the question is, can you make irregular structures that have some function? And I point to you or to me as examples of something in which no robot put us together; we put ourselves together. So biology is the master of self-assembly.

FLATOW: And we're just then touching on in nanotechnology where that might lead to.

Dr. WHITESIDES: Yes. And the issue with many of the things that are happening in nanotechnology now is that the field's really just at the beginning. It's, I think, better to call it nanoscience than nanotechnology. And if you look at a new field as it emerges, it's a nice idea that a single invention makes a field--if you have a transistor, then all of a sudden you have microelectronics. But in practical fact, it usually takes a few hundred inventions. You need silicon, you need the transistor, you need software, you need FORTRAN, you need displays, you need mice, you need all the rest of the things that go into a computer system in order to have a technology. And what's happening now in nanotechnology is very much that. People are coming along with bits of science which will become bits of technology and eventually it will add up to more than is there right now.

FLATOW: We've seen people making transistors out of DNA now.

Dr. WHITESIDES: Seen people making transistors out of DNA, and in fact people are making transistors at the nano scale. If you look at what the very skilled engineers in Intel and other companies are doing, you find that the dimensions of the objects that they work with have very quietly gone well below the 100-nanometer mark. So nanotechnology is with us. But a lot of that is what I'll loosely call evolutionary nanotechnology. That doesn't make it any less interesting than or less important than revolutionary technology, but it's maybe a little bit less flashy.

FLATOW: So we really don't know where any of this is heading, and that's sort of exciting.

Dr. WHITESIDES: Well, it's very exciting because, as with many technologies, it's a technology that touches on so many parts of the world that we don't quite know where the big impact will be. I mean, if you ask where will nanotechnology almost certainly be important, one place will be in computer memories because it'll be possible to store much greater amounts of information in much smaller space. Now that doesn't sound perhaps breathtakingly exciting. On the other hand, if you imagine a world in which information is fundamentally free and it's accessible to anyone, it has enormous consequences for education because perhaps we don't need to learn anything anymore; we mostly need to know how to find it. It has enormous implications for how countries value themselves competitively. If everything that everyone knows is in a common pool and it's just a question of who reaches in most efficiently and grabs the information, that's very different from the world that we've all grown up in. I mean, many interesting differences. So these technologies that are kind of at the core of society--it's not easy to understand how their consequences play out in the top-level things that we see and touch and feel.

FLATOW: You seem to be saying that you believe that all knowledge should be open-source, then.

Dr. WHITESIDES: Well, I don't know that it should be, but I think it probably will be. It's pretty hard to keep things private once the Net is what it is.

FLATOW: And I noticed by reading about your laboratory that you really have a cross section of different disciplines. People from chemistry, biology, all kinds of different fields, engineering, a wide variety of expertise. Is that because you just never know where things are coming from?

Dr. WHITESIDES: Certainly I don't know. And the students who are in graduate school, the postdocs who are in the laboratory, are here to learn, but what they are learning is not, as in the past, a specific discipline for a specific well-defined future. What they are in principle learning is how to be as flexible as they can to take the opportunities as they come along, since they're coming along at more and more rapid rates. And so it's really immense fun to put together a group that has such a broad range of interests and just let people talk to one another. When they do, wonderful things happen, as, for example, this algae which requires knowing something about microbiology, something about organic chemistry, and then having an interest in being able to move small loads around, which is basically a problem in nanotechnology.

FLATOW: Speaking of graduate students, are you having trouble getting, keeping, making sure you can have a supply since we're seeing, you know, the number of graduate students drying up in this country?

Dr. WHITESIDES: No. Certainly there are lots of good graduate students. The interesting issue with graduate students is the question of globalization because the United States, as a technologically sophisticated country, needs to be able to try to attract, at least compete strenuously for the very best people it can find on a global basis. And one of the consequences of 9/11 has been various activities which have made it much more difficult for foreign students to get into the country and to stay once they're here. And this is, to me, a really most unwise course of action because we really need these smart young people.

FLATOW: You know, but on the other hand, we're not graduating as many scientists and engineers as we used to.

Dr. WHITESIDES: We're not, but that's people's choices. I mean, and people vote with their feet to do what they think is the right thing to do. And if you ask me why it is that American students seem to be a little bit less interested in science and engineering than they were, I'm not sure that I can answer the question.

FLATOW: You don't think education and influence of education has anything to do with it?

Dr. WHITESIDES: Well, i think it's perception, as much as anything else, of opportunity and jobs. But it also is the case that of course science and engineering have always been thought of as being difficult. And they are difficult. And with difficulty comes lots of amusement and the ability to do complicated and difficult things. That may or may not be the style of the times.

FLATOW: How do you come up with fresh ideas to work on?

Dr. WHITESIDES: There's never any shortage of fresh ideas. You can either start from problems such as disease or you can start from phenomena, looking for things that are new, or you can start in early-stage technology in which you ask questions like, how do you move a load around on a micron scale? So the issue is not looking--it's not difficult to come up with new things to work on. I tell the students there are three stages in a research project. There is a stage in which you define the problem and decide what the strategy's going to be, and then there's a stage in which you solve the problem, and then there's a stage in which you sell the solution to the community. And the easiest one of these is usually solving the problem. And probably the next most difficult is figuring out what a good problem is. But there really are so many around that you just have to look at the world around you. Curiously, one of the ones that's hardest is to, once you've solved a problem, to get people to pay attention because, after all, it's a new idea if it's a good problem. Everybody's a little conservative about new ideas.

FLATOW: Yes, but on the other hand, if you hook up with a corporation early on, they're going to be wanting to know how to sell it to the community first before anything else.

Dr. WHITESIDES: Corporations are pretty conservative now.


Dr. WHITESIDES: I mean, capitalism is a very efficient system, but it doesn't favor ideas that take a few years to work out. So one of the issues that the United States has to think about just a bit is the general strategy for how one invests in research, how much should be short-term and how much should be long-term. And by long-term I mean sort of three to five or somewhat longer than that years, because we tend to be pretty short-term as a society now.

FLATOW: And who makes that decision?

Dr. WHITESIDES: Well, it's a good question. And the part of corporations--with large corporations it's largely made by their owners, who are often financial institutions or individual stockholders who are interested in doing what they need to do as quickly as possible. And the whole atmosphere of globalization is one in which decisions have to be made rapidly. You have to move into or out of something efficiently, and you can't really understand financially how it's a good thing to do to start a program of investment that takes 10 or 15 years to get to an answer, other than in select areas such as pharmaceutical development. So all the pressures are in trying to make things rapidly.

And then as far as public investment goes, that's done by some combination of people who set government policy and what's called the peer review community, which is in fact us in the universities--we in the universities.

FLATOW: And it seems like some of our technologies have made wrong decisions or the wrong bets in recent years.

Dr. WHITESIDES: In what sense?

FLATOW: Well, for example, the car industry. GM, Ford--they're almost on the ropes and, you know, GM's losing billions of dollars because they're just not selling the cars that people want anymore.

Dr. WHITESIDES: It's a very interesting issue. The great change in the automobile industry came in the early '80s when Toyota and the other Japanese discovered that consumers really did care about quality. Now the systems that they used to make their automobiles with high quality were in fact invented in significant part by Americans, particularly by a man named Gimming(ph)--Gimming.

But the question of how one gets really first-rate cars off a automobile production line is of course a complicated question of first having the right kind of design, second having a manufacturing system that makes things work, third having a work force that is alert and pays attention and cares about the quality of the product. I mean, it's not simply a technology issue. And I think that's another thing that the US has to pay attention to. But you are correct in saying that the US has made some right and some wrong decisions. The US basically invented SUVs. Now SUVs were quite profitable. There are, I think, a number of us who have objections to SUVs on a variety of reasons, but they did sell fairly well for a while.

FLATOW: We're talking with George Whitesides this hour on TALK OF THE NATION/SCIENCE FRIDAY from NPR News.

And of course now you have Toyota making hybrids and American companies having to license the technology from them. It's almost like a deja vu 1975 all over again.

Dr. WHITESIDES: Yeah, it's something which I don't understand, either. General Motors made a serious effort to get started early in all-electric cars. And they had the first pure electric, which they developed into, I think, a successful prototype and actually had a number of them on the road in the hands of drivers. Pure electrics turn out to be, at least using existing technology, not as practical and not as useful as the hybrids. And the Japanese had a good focus on that and moved early and aggressively. And you're right, those are excellent cars.

FLATOW: And they also have a government agency that helps to shape the direction technology takes.

Dr. WHITESIDES: That's true, but now that becomes a much more arguable point. There are lots of folks, myself included, who would just as soon not have government setting policy on those kinds of matters. There are sorts of decisions, I mean, things that involve very large public investment and which have enormous consequences for the economy that are beyond the scope of individual corporations. And transportation may well be one and arguably things like energy policy are another, in which the government should be involved. But for the government to pick the technology that's likely to work has not generally worked very well.

FLATOW: Yeah. Yeah. Where do you see science and technology going in China?

Dr. WHITESIDES: Well, China has an enormous, enormous job just to bring its society up to that of the rest of the world. So roads and bridges and communications systems and all the rest of the things they take for granted. A big fraction of China's effort will go into providing the services that we take for granted. But China is very ambitious and Chinese are, I think, as a people right now very willing to be focused on science and technology as solutions to problems. So that I think that we should expect to see very serious competition and very effective competition from China in all the areas that we regard to be profitable and strategic.

FLATOW: There are some people who've said, `Oh, China's just a new Japan and look what happened to them.'

Dr. WHITESIDES: Well, I think that, for one thing, Japan's not doing as badly as people make it out to be. And for another thing, there are a lot of Chinese and enormous resources. And, you know, it's not necessarily a bad thing for China to be a very successful company. In fact, I think it's generally very a good thing for China to be a successful country. It represents a major market; it represents a new source of technology globally, particularly if we're smart enough to pay attention to what they develop. And it provides a way of building a network between China and the rest of the world which ultimately I think helps to stabilize the world. So I'm absolutely for it. But I don't think that it makes any sense at all for us to either discount the ability of China as a country or Chinese, individual Chinese, as individual citizens and scientists or to take it more seriously than should be. But we do have to get our act together.

FLATOW: Well, I want to thank you for taking time to talk with us. It's been fascinating. And we'll have to have you back on and pick the rest of your brain.

Dr. WHITESIDES: Terrific. Thank you very much for the invitation.

FLATOW: Thank you very much. George Whitesides is the Woodford L. and Ann A. Flowers University professor in the department of chemistry and chemical biology at Harvard University in Cambridge. He's also co-author of a great, great visual book, a great coffee table book called "On the Surface of Things" with Felice Frankel. And as you know, Dr. Whitesides is an expert on surfaces, and there's some great photographs, color photographs, of the surfaces that he is quite familiar with.


FLATOW: Surf over to our Web site at You can leave us e-mail there. Also you can download a podcast of SCIENCE FRIDAY, back editions of SCIENCE FRIDAY. And also we got free curricula for teaching SCIENCE FRIDAY from Kids' Connection. Now that the school season is starting up in September, we'll start making more curricula available for teachers and kids there.

Have a great weekend. We'll see you next week. I'm Ira Flatow in New York.

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