SOMETHING VERY SMALL has the potential to make some very big changes in our world.
Over the past decade, nanoscale materials and devices so small that hundreds could fit inside the diameter of a single strand of hair, have begun to show up in everything from golf clubs to targeted drug delivery systems and new types of optical and electronic devices. In the laboratory, researchers are demonstrating nanoscale devices that may hold the key to quantum computing, artificial photosynthesis, high-speed genomic analysis, and even invisibility cloaks.
In fact, nanoscience’s reach is so broad and so profound, it is often difficult to understand how its various strands are alike and different, and what we must do to nurture further innovation. The Inaugural Symposium of the new Kavli Energy NanoScience Institute (Kavli ENSI) at University of California, Berkeley, and Lawrence Berkeley National Laboratory seems a good time to step back and address some of those issues, as well as nanoscience’s future potential.
Kavli ENSI, which is dedicated to energy-related nanoscience research, is the fifth nanoscience institute funded by The Kavli Foundation. The other four, each with its own special focus, include:
- Kavli Nanoscience Institute at the California Institute of Technology, which seeks to apply nanoscience and nanotechnology to quantum matter and information, biomedical engineering, and sustainability.
- Kavli Institute at Cornell for Nanoscale Science, which develops and pioneers the use of next-generation instruments for exploring the nanoscale world.
- Kavli Institute of Nanoscience at Delft University of Technology, which investigates bionanoscience and quantum nanoscience.
- Kavli Institute for Bionano Science and Technology at Harvard University, which develops new methods and instruments to study nanoscale biology and apply its knowledge to health science and biotechnology.
In advance of the Kavli ENSI Inaugural Symposium, the directors of three Kavli nanoscience institutes discussed the future of nanoscience. They include:
- PAUL ALIVISATOS, director of the Kavli Energy Nanosciences Institute at University of California, Berkeley, and Lawrence Berkeley National Laboratory, and director of Lawrence Berkeley National Laboratory.
- PAUL McEUEN, director of the Kavli Institute at Cornell for Nanoscale Science.
- NAI-CHANG YEH, co-director of the Kavli Nanoscience Institute at the California Institute of Technology.
The following is an edited transcript of a roundtable discussion. The participants have been provided the opportunity to amend or edit their remarks.
THE KAVLI FOUNDATION: Nanoscience encompasses everything from quantum computing and understanding the brain to creating targeted medicines. It also seems makes the seemingly fantastic possible, such as teleporting information and invisibility cloaks. How can all these things fall under the heading, "nanoscience?" What ties them together? Are they really that similar?
NAI-CHANG YEH: Size. The prefix "nano" is short for nanometer, and it refers to length scales in the billionths of a meter. All the topics you mentioned deal with objects and phenomena that take place at similar length scales. While nanoscience is a multidisciplinary field that branches off in many different scientific and technical directions, its methodologies and approaches to fabrication, characterization, and integration of nanostructures are similar across those fields.
PAUL ALIVISATOS: Maybe I could jump in and add that nanometers are not a randomly chosen length scale. It's the size where our building blocks -- atoms, crystals, and molecules -- start to show certain types of phenomena, or they achieve sufficient complexity to demonstrate certain functions. So, control of matter on the nanoscale becomes unusually important.
Until recently, we've built nanoscale objects by carving small structures out of larger wholes. This top-down approach limited our ability to access the nanoscale realm. As we learn to build from the bottom up, we can access the type of things you mentioned in your question, like quantum phenomena and the complexity and functionality of an enzyme catalyst. The length scale is a very specifically relevant one, and that's why the applications of nanoscience can be so broad.
PAUL McEUEN: I'll throw in one other thought. In addition to being an important length scale, nanoscale is also defined by its difficulty. It pushes researchers from every discipline outside of our comfort zones. It's too small for solid state physicists, it's too big for chemists, and it’s too interdisciplinary for biologists. We don't know how to play very well at that length scale, all the way from imaging to manipulation and control.
ALIVISATOS: Meanwhile, we can be very jealous of nature, which seems to have no trouble doing it at all.
TKF: Clearly, this is field with great diversity and rapid growth. That makes it hard for people to get their arms around it. Can you explain how our understanding of nanoscience is changing, and discuss its potential?
YEH: I completely agree with that. Today, we seeing new approaches to put those building blocks together in novel ways. We can build metamaterials with unusual properties. We can couple functionalities that don't usually go together, like microwaves and optical lenses, do innovative physics, or manipulate quantum information. All of these things are really new dimensions in our study of nanoscience and nanotechnology.
ALIVISATOS: Now the research is more fun, because we're not stumbling around completely anymore. We can approach these problems in a more interesting way because we've got a little bit more control.
McEUEN: I could say this is a very optimistic viewpoint.
ALIVISATOS: Well, at least we're stumbling around on a different stage, let's put it that way.
McEUEN: Like a child who has his fingers in the paints, and now we're going to have to make art.
ALIVISATOS: Exactly like that. At least we've got the paint.
YEH: I would like to bring up another point. People are realizing that we have to deal with the hazards and safety of nanosystems, and that as we develop the capability of nanoengineering biological systems, there are also issues related to ethics. We're not just scientists playing in our sandboxes. We also need to be aware of some of these societal issues.
TKF: Could you give me an example of a health, safety, or environmental issue related to nanoscience?
YEH: For instance, if certain types of nanoparticles get into the environment, they may not decompose. They might prove hazardous if they get into the bloodstream. Airborne nanoparticles might get into your lungs. Nanomaterials promise many benefits, but people must also pay attention to potential hazards as well.
ALIVISATOS: I agree. These are important issues, and people have been sort of grappling with them for a while, actually. We've made a lot of progress in understanding nano toxicology and availability intellectually. One of the things that's been difficult is that you can start with nanoparticles with identical compositions, and depending on how you formulate them, they will behave very differently.
For example, we can coat nanotubes so they disperses very nicely into a liquid or precipitate as an ultrafine powder. We can embed the same nanotube inside a chunk of glass and it will never come out, or make it as a powdery substance that wafts into the air. We start with the same building block, but each formulation behaves differently. That's made it more difficult to understand the toxicology. After all, how do you build a firm foundation for the science when the formulation is as important as the substance you're looking at?
The nanoscience community started working on these issues almost from its start, though maybe not as systematically it could have. Over the past five years, I think researchers have made a lot of progress in building those foundations, learning how to classify these materials and formulations in ways that allow a lot more understanding.
McEUEN: Actually, the health and safety issues that we're facing are not unique to nanoscience in any way. Chemical safety issues have a long history. Take, for example, thalidomide, a drug that was introduced for morning sickness in the 1950s. No one realized that there were two chiral forms, one left-handed and one right-handed. One made you feel better if you had morning sickness, the other gave you birth defects. So we need to understand the complexities of what we're working with, and not just label it based on its atoms.
Also, there are well-defined regulatory structures designed to deal with these issues. Most nanoscience research does not present particularly unique challenges in terms of how we regulate other chemicals or biological agents or what have you. I think that's good news. It means, there's a system out there for us to plug into. Of course, nano has unique aspects, but it's not like we have to build something new from the ground up.
TKF: Is there a role for nanoscientists in dealing with health and safety?
TKF: Researchers often talk about grand challenges, big questions whose answers promise to open up new possibilities and unexpected avenues of research. What are the grand challenges in nanoscience?
McEUEN: I'll throw out one. One of key problems we face is that we don't have good tools. What we want is a magic box, where we can put in a nanostructure and find the location and movement of all the atoms as they respond to external stimuli. In other words, we want to make atomic-scale movies of what's happening inside nanostructures. That would push things forward in a thousand different ways, because very often we don't know what's going on and we have to infer indirectly. This year's Nobel Prize in chemistry for super-resolved microscopy was a small step forward toward such a magic machine.
YEH: I completely agree with Paul on this one. Basically, we need a four-dimensional tool that can characterize properties spatially over time. There are some tools out there, but generally, if you get the spatial resolution you don't have the time-dependent information, and to do both together is not easy.
Another big challenge is the integration of a large number of nanostructures into functional devices. And the reliable mass production of those nanodevices with proper error corrections. Nanostructures are usually more prone to errors than large structures, so this is not easy.
Another grand challenge is understanding how the properties of nanoscale objects relate to the properties of larger structures built from those objects.
Those are technical challenges, and they are important. There are also other challenges that are more societally related. As our research grows more expensive, we need to find ways to fund our work at a time when our government seems to be reducing its support. Also, very multidisciplinary nature of nanoscience poses challenges to our education, training, and research.
ALIVISATOS: Maybe another way of saying that is we face both inward-looking and outward-looking challenges. Developing better instruments is an inward-looking challenge. The outward looking challenges touch on societal needs, and there are many of them.
For example, the BRAIN Initiative, which uses nanotechnology to measure how neurons function in large groups, is very, very important. There is also a slew of needs that relate to energy and the environment, such as whether we could make materials that have an intrinsic ability to be recycled easily.
I think there will be increased long-term interaction between those inward and outward-looking challenges. The field's just getting to a stage now where the outward-looking challenges feel more achievable, although they're still really hard.
McEUEN: Paul and I were recently part of a panel that reviewed the National Nanotechnology Initiative grand challenges. These included nano-enabled desalination of seawater to solve the emerging water crisis. This was an example of outward-looking challenges. Another was the creation of 3D nanoscale printing, which was more of an inward challenge.
I also wanted to mention a grand challenge that is both inward and outward looking, one that we have been discussing for probably two decades. This would be making self-replicating systems from simple, basic constituents. This type of system would borrow from biology, harvesting energy to manufacture copies of itself and perhaps even improving its functionality over time. I can't help but think it's the most interesting thing out there.
“Think, for a moment, about all the garbage people generate. Imagine having materials that, instead of making copies of themselves, would break apart into constituents that we could reuse to make other products.” —Paul Alvisados
ALIVISATOS: In the two decades we've been thinking about it, I'm not so certain we've gotten all that much closer to achieving something like that. It is a really interesting challenge, of course, but I don't know anybody that's seriously got their sights set on being able to do this in the next 10 or 20 years, or in any other reasonably foreseeable unit of time.
But borrowing from biology opens some very interesting doors. Think, for a moment, about all the garbage people generate. Imagine having materials that, instead of making copies of themselves, would break apart into constituents that we could reuse to make other products.
That would be a big step forward. A characteristic of life on the global scale is that it unmakes what it has done. Otherwise, it creates a big, unsustainable waste problem. I think that creating reusable nanomaterials is actually pretty achievable if we work on in it more systematically.
YEH: We can also borrow from biology to achieve energy sustainability. For example, nanoscientists hope to learn from nature and become very efficient at artificial photosynthesis or splitting molecules. We could do this in ways that would be simpler than imitating nature's complex biological functions, and that would be a big step forward.
ALIVISATOS: That's a good example. That way, if we make carbon dioxide by burning fuel, we could turn the carbon dioxide back into fuel. That would close the cycle, and you have to close the cycle if you want to be sustainable on a planetary scale. When we learn biology in grade school, it's all about cycles -- nitrogen, carbon, water, whatever. That's what nature evolves towards, because that's what's stable when you talk about really big systems.
TKF: There are many great challenges. So, should nanoscience researchers try to prioritize them? One reason physicists and astronomers can line up money for expensive experiments is that they can agree on the experiments they need to run. And really, they are interested in knowledge for its own sake, while you want to give us cheap renewable energy and safe drinking water. Is there any chance of nanoscience researchers getting behind a single research agenda and lining up the money for breakthrough experiments?
ALIVISATOS: If you aggregate all nanoscience research, it adds up to many billions of dollars. It's just done in many smaller pieces. Now, I happen to believe that, in many cases, there are enormous advantages to large organizations that bring people together to achieve a goal more efficiently through larger scale cooperation. I think the astronomers do that because, if they make a small instrument, they can't learn anything new.
Nanoscience is different. We're still at a stage where we can make a lot of progress in a laboratory with a small group of faculty, post-docs, and students.
That said, I'm so happy that astronomers get major funding. It means that society is still moved to understand what goes on around us, and that's a really good thing. But I don't look at that funding with much jealousy myself. Given our stage in understanding, I think nanoscience's scale of funding makes a lot of sense.
YEH: That's a good point. I also want to mention that when astronomers are ready to take the next big step, they often rely on a people with completely different backgrounds and strengths. For instance, some cosmology experiments rely on people who can make excellent superconducting nanoscale devices. My colleagues at the Jet Propulsion Lab team with condensed matter physicists and low temperature physicists to develop the new tools and concepts needed to further our study of the cosmos. So, while we funnel that money into astronomy programs, we are also pushing many other research fields, including nanoscience.
McEUEN: I want to make two completely independent points. The first is that one thing astronomers have going for them, even more than agreeing on research goals, is that they've got great pictures.
YEH: In false colors.
McEUEN: Yes, but they use their pictures well. They tap into wonder, and people will fund wonder. And I think we in nanoscience could do a better job of tapping into wonder.
The second point is that we really have to make sure that the type of funding matches the type of research. There's no doubt that we could do big projects, especially in areas like electron microscopy and imaging, where researchers just need a bigger, better instrument.
But many of the major advances in nanoscience over the last couple of decades have come from oddball people working in strange corners of the field. Graphene is the classic example. Everybody thought it was a complete waste of time, right up until it took over the nano research world.
My second example involves imaging, and two guys who were out of work and building an instrument in their living room. They won the Nobel Prize in chemistry this year. It just shows that it's not always big money that's needed, but also money for really creative, out-of-the-box stuff. In a field like nanoscience you really have to fund both.
ALIVISATOS: I totally agree with that, Paul, but there are also fields where we need the big push. Brain imaging is an example. People are very close to reaching the threshold of what can be achieved in individual laboratories. The complexity of the problem has reached a scale that is very, very challenging because it requires integration of detectors, materials, computing and many other types of engineering.
Brain science is at the threshold, and to cross it, we need to change how we are organized. That takes a little bit of time, but we've seen this before. Take, for example, the human genome initiative. We started with small, laboratory-based science and learned to manipulate and sequence DNA. But larger scale projects created the field of genomics that we have today. That was unachievable by individual laboratories. It required the community to come together. It was hard to do in the beginning, and I think that's where brain projects are at the moment. Much of the nanoscience we need is still in its cottage industry mode.
YEH: I see your point, Paul. Bigger themes, like the brain, draw people together and enable them to deal with complex issues. Under a well-designed plan, the government probably can come in and support these bigger themes.
On the other hand, we should not only fund big projects. It's also very important to nurture independent researchers with very creative ideas. But supporting high-risk research is an area where the United States is getting worse. That's something that other nations -- China and others in Asia -- are doing much better. They are investing a lot of money in trying to encourage creativity, and yet in this country we're seeing dwindling support for high-risk projects by creative individuals.
TKF: What do you think about what Nai-Chang is saying? Is the government spending enough on the right type of research? And what roles do you see for non-government funders, such as foundations and corporations?
McEUEN: I think we are talking about two completely separate questions. The first involves the total amount of research funding, and if you ask any scientist, he or she will tell you that we always need more.
The second question is about whether we are spending our research dollars efficiently and effectively. I think a lot of us feel like we could do much, much better. I think it dovetails with what we've already discussed. Sometimes we do need grand challenges that identify important national needs or major projects. We are seeing attempts by federal funding agencies to adopt this model to some degree.
But we also need to fund the most creative and best people. University professors create science, but our real product is the people we train as we pursue that goal. And supporting our best people is the key thing that we need to do better. We need to give those people the freedom to do creative work without overburdening them with quarterly reports aimed towards an objective that is going to change every quarter, because that's the way we fund science now.
I think funding the people, not the project, is one positive step forward. We could, for example, fund a lot more National Science Foundation fellowships for graduate students, rather than supporting those students through individual and investigator grants. Having their own funding would free students to vote with their feet by moving to the most exciting topics, and enable them to explore some crazy idea. Of course, they would do this in concert with a faculty member, but there would be a lot more freedom of movement than in the current system.
For both young and senior faculty, funds that allow us to try out our craziest ideas and really take risks are very, very important. That is money that's very hard to come by.
“Nanoscientists hope to learn from nature and become very efficient at artificial photosynthesis or splitting molecules. We could do this in ways that would be simpler than imitating nature's complex biological functions, and that would be a big step forward.” —Nai-Chang Yeh
ALIVISATOS: I think right now is a really interesting and very positive moment in funding. This is exemplified by Fred Kavli, a very practical engineer whose interest was always in really new ideas. So he dedicated his fortune to fostering new fundamental discoveries.
He is an exemplar of a whole community of scientific philanthropists that did not really exist 20 or 25 years ago. The science community has an unusually positive opportunity to engage with these people, because they can add value to our existing and very impressive federal science funding system. I think this is really going to be enabling.
You also mentioned companies. They have become more focused on the immediate term, yet they realize that they have enormous needs for longer-term research. As a result, the partnerships between companies and universities have gotten much deeper and more substantive over the past 10 years. It looks like that trend is going to continue.
I think these are good trends. The philanthropists want to promote early discovery, and the companies are asking us to focus on the technologies they really need. Both types of research enrich the science community in the United States, and create avenues to do really vital work.
YEH: I completely agree, and want to inject one more point. Generally, government funding comes with regulations that limit how you interact overseas. Foundations have no such limitations, and make it easier to bring people together beyond national borders. The Kavli Foundation, for example, established institutes around the world. They play a very, very important role in teaming up international talents and facilitating interactions through conferences, workshops, or even exchange programs.
TKF: Earlier, Paul said that his most important product is the researchers he trains. I wanted to ask about that. At the nanoscale, the differences between conventional disciplines begin to blur. If you want to study the mechanical properties of materials, you might need to understand quantum or electrical interactions. If you want to investigate chemistry, you may need to know about optics and electromagnetism. Do we need to train students differently to study nanoscience?
YEH: I'm still a strong believer that we need to train students to be very, very strong in one of the core disciplines. Then, of course, if they're moving into nanoscience or nanotechnology, we need to help them broaden their horizon beyond that core. If they're dealing with nanoscales, that's a size where quantum mechanics matters. Even biologists investigating nanoscale phenomena must be very strong in the physical sciences.
ALIVISATOS: I also believe students need to learn one core discipline really well, because otherwise they won't be able to solve new problems when they come across them. But, to make an analogy, they also need to learn to speak multiple languages better.
Here's what I mean. We live in such an interconnected world, anybody who speaks several languages can automatically do more things than somebody who speaks only one. I think nanoscience is like that. It has all these interconnections. So, while it's important to really be good at one language, like physics, all the more power to you if you can learn one or two more.
In fact, I think most students yearn to learn another language or two. So the question becomes, how can we train them up in one discipline while helping them get better in one or two others? The students want to do it, and in many cases, they're just doing it themselves. The whole way the current generation of undergraduate and graduate students learn is different than the way I might have learned because they have different and more efficient ways of accessing information. So, for universities, the challenge is to move the curriculum along so they build that strong foundation while allowing them to do more to learn that a second or third language.
McEUEN: I agree. And just to follow up, what we don't need is to create and learn a new language and then not be able to talk to anybody but ourselves.
ALIVISATOS: That's right.
YEH: That's an excellent point.
ALIVISATOS: The languages that are out there are already quite nice.
TKF: So, final question. You're all involved in some of the most exciting nanoscience going on right now. If we were to meet again in five or 10 years, what do you think we would be talking about?
McEUEN: The past 50 years has all been about miniaturization of information technologies. I think the next 50 will be about the miniaturization of what I call machines: nanoscale devices with physical parts that move and can do anything from drug delivery to disassembling themselves for recycling. Small scale machines are going to be a huge growth area, and I think that's what we will be talking about in 10 years.
“The past 50 years has all been about miniaturization of information technologies. I think the next 50 will be about the miniaturization of what I call machines: nanoscale devices with physical parts that move and can do anything from drug delivery to disassembling themselves for recycling.” —Paul McEuen
ALIVISATOS: I'm hesitating here because I see our field reaching out into so many disciplines. There's progress happening in so many areas, I have a hard time choosing any one of them.
YEH: I think we will be talking about integrating nanoscale devices and small machines into nanosystems with special properties. Like Paul, I see many different directions where we can go. I believe that some years from now, we will see advances in information, communication technology, energy, and sustainability, as well as new materials based on nanotechnology, and new tools to better understand nanosystems. I see major things happening in nano-facilitated medicine, and, as we learn more about brain function, new types of artificial intelligence and a better understanding of complex biological systems.
ALIVISATOS: I'm hoping that people will look back on this moment as a very special one, because this was when nanoscience began to change the way we look at the world. It is like a movement, a new way of thinking and bringing things together. Instead of trying to break everything down into individual disciplines, nanoscience show us how to bring them all together. It represents an important stage of scientific development, and has many implications for technology.