An international award of Japanese origin, the Kyoto Prize is presented to individuals who have made significant contributions in the fields of science and technology, as well as arts and philosophy. Kyoto Prize laureates are those who have made an extra effort to plumb the depths of their chosen fields and profoundly inspired the scientific, cultural, and spiritual betterment of humankind through their achievements. In this series of “Unearthing the Words of Kyoto Prize Laureates,” we will interview the past laureates of the Kyoto Prize and take a closer look at the words that they delivered at their Commemorative Lectures to get to the heart of their unique ideas, thought process, and attitudes as inquirers. In this first installment of the series, we had the pleasure of interviewing Dr. Toyoki Kunitake, the 2015 Kyoto Prize laureate in the Advanced Technology category.

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Toyoki Kunitake
Chemist. Professor, Institute for Advanced Study, Kyushu University; Chief Director, NanoMembrane Technologies, Inc.; Research Supervisor, Advanced Catalytic Transformation Program for Carbon Utilization (ACT-C), Japan Science and Technology Agency (JST) and recipient of the Medal of Purple Ribbon 1999 and the Order of Culture 2014. Read more

Nishimura　Could you tell us first about research themes that you have worked on?

Kunitake　Certainly. I received the Kyoto Prize in recognition of my discovery of synthetic bilayer membranes. Bilayer membranes form the basic structure common to the biological membranes, which surround biological cells. These biological membranes are extremely thin, between 7 and 10 nanometers (nano means one-billionth, or 10^-9). In order to carry out biological functions, they have very complicated structures. If we see each of them simply as a membrane, the outer surface is hydrophilic (having a strong affinity for water) and the inner side is hydrophobic (having a strong affinity for oil), and the membrane is formed as molecules gather on each side.

Kunitake　As I was originally working on synthetic polymers like plastics, I began asking myself, “What are the differences between the shape and structure of synthetic polymers and the extremely complicated structure and functions of their biological counterparts?” Then I figured out what is required to form a two-dimensional molecular configuration, to start creating a two-dimensional membrane with synthetic materials in the lab. At the same time, I was interested in how to fill in the gap between biological membranes and synthetic materials, and succeeded in demonstrating that synthetic molecules could produce a membrane structure by self-assembly, that is, a synthetic bilayer membrane.

Nishimura　I’m sure back in the 1970s, when your research on synthetic bilayer membranes started, the idea that “synthetic molecules could spontaneously produce bilayer membranes—a basic structure common to the biological membranes of living cells” was innovative, to say the least. How did you even come up with such an idea?

Kunitake　At that time, there were rather complicated discussions on biological membranes taking place from a biophysical point of view, that is, “Is it the case that biological membranes are two-dimensional because the molecules that comprise membranes have a very special structure?” Because I was studying synthetic polymers, I had my doubts about the question. “Why do they think such a complicated structure is necessary?” I wondered. So, I decided to figure out what was necessary for the molecular structure to be configured two-dimensionally.

Kunitake　To form a structure like a membrane, it is necessary that small molecules gather two-dimensionally rather than randomly. Also important are the stability of interfaces,^*1 which maintains the structure of an extremely thin membrane even when submerged in water, and the aggregation property, which enables molecules to be neatly configured side by side inside a membrane to form a larger structure.

With the belief that it was not that difficult to meet these requirements, I tried various types of molecules one by one to see if they would form a membrane. For instance, focused on amphiphilic synthetic molecules, which contain two distinct components with different affinity for the solvent, in which one part possesses a high affinity for water and the other part has a strong affinity for oil like soap molecules. I used an electron microscope to see if they would form a membrane structure.

Then, I discovered that a membrane structure is formed by molecules which have a positively charged hydrophilic group and two fatty acid alkyl chains^*2 connected to the hydrophilic group. This discovery received significant interest in the research circle, but one question remained—would it be extended to molecular organizations in general? In the end, it took some twenty years of molecular design, that is, combining hydrophilic groups and hydrophobic groups in effective manners, to reach understanding as unified concept of general molecular organization.

Biological membranes must fit into the ecological link of forming a membrane with materials from the natural world. The membranes must then destroy themselves after fulfilling their jobs to maintain the cycle. If we limit synthetic materials to form a membrane, however, our sole task is to find whatever forms a membrane, which gives us much more room to think.

Nishimura　Do you think that, for an idea to develop into a discovery, persistently trying possibilities is the key?

Kunitake　I think so. You need to be reckless to some extent. You may not see a possibility if you give up because the chance of an idea failing is 95%. So, sometimes I find myself departin
from what is deemed reasonable and throwing a Hail Mary.

Nishimura　Not a few young researchers say that they have ideas but hesitate to take action on them or that they don’t see what they should be doing until an idea comes to them. Having spoken with you, I gather that you are not advocating to rush ahead haphazardly, but instead, you are saying that researchers can take that first step only when they have a hypothesis, a course of action to take, and the knowledge to back both of those things. Am I understanding correctly?

Kunitake　Yes. Both a hypothesis and background knowledge are important. Only knowledge is not sufficient to keep you on a difficult path, however. There is always a risk of getting stuck somewhere because it costs enormous economic and time resources and takes unwavering determination. To avoid this, you may need some grit to carry on with what you’re doing.

Nishimura　What would you say to those researchers who reach an impasse because they do not have the courage to believe in their own ideas?

Kunitake　For one thing, they might go through the abstraction process, that is, dropping one element after another to focus on the minimum requirements.

Take, biological membranes as an example. To carry out the functions of living organisms, they have an extremely complex and diverse structure. If you think “a membrane is formed because of its very complicated structure,” that’s the end of the story. Instead, I asked myself, “What are the requirements to create something like a large biological membrane with a relatively simple structure?” and abstract my thinking, as in the “ability to self-assemble, with a hydrophilic group and molecules being configured side by side stably.” Then I begin the process of materialization, which is to reflect the abstract concept in my head onto each molecule.

To sum, I conduct research by going back and forth between the two different processes of “abstraction for exploring possibilities” and “materialization for producing practical outcomes.”

Nishimura　I believe that the abstraction process is of paramount importance, while the materialization process takes a very long time, right?

Kunitake　Materialization does take time because it involves actual work. You have to keep in mind what stage you are in, namely, the “abstraction stage” or “somewhere between abstraction and materialization.” Abstraction and materialization are processes that cannot be done without throughout your research; from your initial idea to the research outcome, you must constantly go back and forth between the two processes.

Nishimura　Was there a particular moment that made you realize the importance of going back and forth between abstraction and materialization?

Kunitake　If I choose one, it would be that I started by working on synthetic polymers, a kind of synthetic material, and then became interested in biomimetics, which attempts to reproduce biological structures and functions with synthetic materials. To consider how to reduce the complex research of living organisms to a simple form and use synthetic materials to mimic such structures and functions is, so to speak, abstraction. And to consider how to reproduce complex functions of living organisms out of simple synthetic polymers based on the findings of abstraction represents the materialization process. Mind you, I was not trying to reproduce an ecosystem itself. I did start from living organisms, but there was a good chance that I would end up having something that was not a living organism.

Nishimura　If I may sum up, you first set an abstract question as a general research objective, and then set concrete topics along the way, right? I imagine that, if you start pursuing concrete research topics without a broad research objective, you are likely to get stuck when you find yourself at an impasse.

Kunitake　Right. How much significance the outcome of each concrete topic carries can vary in different circumstances. Even if you are moving in the right direction, you can find yourself in serious trouble, with your entire research development coming to a grinding halt. When that happens, you may go back to the drawing board to repeat the abstraction process and determine the possibility of a more general course of direction and your research trajectory. I believe that every researcher is doing this, but it is always necessary to “do a good deal of thinking without fear.” I can safely say that this is one of the critical disciplines for researchers, as I believe it will increase the breadth of their thinking.

Nishimura　While conducting my research, I am aware of the risk of relegating myself to my field of study and nothing outside of it. I also find many wonder how they can widen their horizon. If they learn to abstract things, as you suggest, I think they can raise their viewpoint and expand their horizons. As a researcher, is there any contemporary frame of mind that you think can change how they view things?

Kunitake　When Japan used to produce so many Nobel Prize laureates, the general view was that “Japan’s basic research that dates back to the Meiji period is exceptional.” When the economy began to worsen, however, some started theorizing, “It’s not good because the link between basic research and applied research is missing” or “Japan should put more muscle into applied research.” I still hear these arguments to this day.

My point is, public expectations of research change as social circumstances change. When there is some leeway to be had in their collective mind, their expectations of basic research tend to rise, but they want a greater emphasis on applied research when they run out of leeway. I think this frames the problem incorrectly. It seems to me that the public seeks answers from one or the other, but in reality, basic and applied research are equally important.

If I were to use the analogy of a human body, basic research is the trunk of the body, and applied research is the limbs. When you play baseball, you have to have a robust trunk, or you cannot move your arms and legs as you want to. Or if you train your arms and legs but have a feeble trunk, the overall balance is lost. The same holds true for research. Only when there is a solid foundation of basic research does applied research become useful in addressing specific social issues and economic challenges.

Others speak of the two as two different elements as in, “Basic research is important if you get applied research right” or “From basic research comes brilliant applied research.” I don’t agree with this dichotomy. Just as you cannot think of a human body as independently separate parts, basic research and applied research are two sides of the same coin. I think this is also true for society and science.

Nishimura　In a similar vein, I think students of natural science and the humanities and social science see the same world from different angles. Just as we perceive basic research and applied research as one, can we not perceive academic disciplines of humanities and natural science as one?

Kunitake　I agree. I don’t think humanities and natural science should be in separate frames up to high school education. Otherwise, you end up having a narrow view. Every person has differing degrees of aptitudes that are distinct from others, and so it makes sense to place weight on areas of strength. Yet, I think the government should balance between the two. Someone told me a long time ago that once there was a person who said that “Shakespeare and the second law of thermodynamics should be taught equally.” I do believe that everyone should study at least the basics of physics, literature, and social studies to gain some understanding of them.

Nishimura　You were an avid reader when you were a student, weren’t you? People tend to believe that “literature is not necessary for science researchers.” Young researchers of natural science may be under the impression that “there’s no point in reading Shakespeare.”

Kunitake　I think mere training will do. What they have learned will be of help later and help to expand their world. If you teach both in a good balance, at least in their formative years, it is sure to be of use in some way later in life.

Nishimura　Now, the prevailing idea is to firm up one single aptitude, with the result that many people have tunnel vision as they go about life. You started your career as a researcher more than fifty years ago, but do you think the world of education or research has narrowed in that time?

Kunitake　The common perception now is that one single competence will suffice. Only the highly-competent part tends to receive lofty praise. For example, I have had the pleasure of getting to know European researchers, and they have a very broad range of interests. I know several university researchers play musical instruments well. I guess it is because something was different at the start of their education. In Japan, it often happens that, outside of their field of specialty, there is a complete lack of knowledge, even in fields that would be considered adjacent.

Here, I see the same problem in the case of breadth of knowledge and basic knowledge. The more knowledge you have, the broader your view of the world gets, and the lower the hurdle becomes to access different fields. After all, the world is so broad. I think teaching the expanse of the world or providing students with opportunities to have an experience themselves is necessary.

Nishimura　Without the founding knowledge, you may overlook what is before you and so naturally would miss developing an interest in it. That’s why you need broad training at the initial stage, right?

Kunitake　Yes. Once you’ve lost touch with it, it could become inaccessible.

Nishimura　You succeeded in recreating biological membranes, which had been believed to be possible only through natural processes, using synthetic chemistry. What prospects do you think your research achievements have shown to researchers of future generations?

Kunitake　What I have constantly felt through my research is that there remains much for us to learn about the very precise structures of living organisms. Within living organisms are macro functional units, which contain layers of structured smaller molecules, such as proteins and lipids, and on each layer, a new function is generated. It is very difficult for humans to reproduce this process. Let me give you an example that indicates the paramount importance of this structurization stage. Graphene is perhaps the most obvious example. Now, a graphene sheet is a one-atom-thick sheet material, with carbon atoms and their bonds being arranged in a two-dimensional hexagonal lattice that looks like a honeycomb. If you extend this carbon-carbon binding three-dimensionally, you finally get graphite, or diamond. Basically, you’ll get something that functions very differently between two-dimensional and three-dimensional manners..

Over the past twenty years, nanotechnology has drawn much attention, as it presents the potential of reproducing different levels of biological structures on the nano level by using synthetic materials and the like. I believe we still have vast untapped potential lying there. In terms of what pertains to my research, I am working on the development of membranes that collect carbon dioxide (CO₂) from the atmosphere using a macroscopic nanomembrane,^＊3 a discovery that I made in 2006 in a RIKEN research project.

Nishimura　Would you be kind enough to give us more details about your new initiative?

Kunitake　Absolutely. Before the Industrial Revolution, the atmospheric CO₂ was 0.03%, and now it’s more than 0.04%. So, an increase of a mere 0.01 percentage points is causing massive problems throughout the world. Scientists and engineers are working hard on the admirable “zero emission” goals of emitting no CO₂; instead, we are working on a different approach of “negative emissions.” Using very thin synthetically-produced membranes that we call huge nanomembranes, we plan to collect and confine atmospheric CO₂. It’s important to use thin membranes because less energy is needed if the resistance is low when gases permeate through a membrane.

Gas separation membrane technology is not new, but the sheer amount of energy required to separate gases made it challenging to reduce the large volume of CO₂. It has become known, however, that huge nanomembranes can provide good gas separating performance when atmospheric CO₂ mixed with nitrogen permeates through them. Normally, the thinner the membranes are, the lower the resistance gets, with the result that the separation capacity for collecting selected gas molecules only lowers. Huge nanomembranes solve this bottleneck and are capable of collecting CO₂, which accounts for only 0.04% of the atmosphere, in a reasonably economical manner.

Also, there have been discussions as to what determines the ease of permeation of gas molecules. There are two camps of thought about this: one claims that it is the boundary between the membrane surface and the atmosphere, and the other maintains that some molecules pass through the inside of membrane more easily than others. Our experiment data has shown that the critical point is almost always on the membrane surface. This is a new potential that conventional membranes don’t have.

Nishimura　Wow, some truly exciting developments! So, if we attach a membrane that separates and collects CO₂ to my air conditioner, we can collect the atmospheric CO₂ as we control the room temperature, right?

Kunitake　Right. The indoor CO₂ concentration is about 2.5 times higher than that of the atmosphere. Theoretically speaking, the more persons there are in the room, the more CO₂ you collect.

Nishimura　You’ve made significant achievements as a researcher, but you’re still working hard on new challenges. When you search for a research topic that offers continuous potential, what points do you focus on?

Kunitake　I cannot say I’m 100% active today, but I can safely say I’m 20 to 30% active.

Speaking of research topics, I make it a rule to pursue topics with a common denominator. Both synthetic bilayer membranes and huge nanomembranes have one thing in common: an interface. Of course, every living organism, too, has an interface between a biological membrane and water solution. It is conceivable that we will find new facts about what is happening near the surface of the biological cell membrane that differs from our current understanding.

Sugimoto　It’s clear that you enjoy your research from the way you speak of it. I imagine, though, that there were periods that you had to endure in which nothing came of your efforts, maybe even for years at a time. How did you get over such difficult times?

Kunitake　For the first several years after I began working on biomimetics, my ideas didn’t seem to go anywhere. It was when I was an associate professor, and I was going through a very tough time. Because I was simultaneously working on a bit more orthodox research on polymers, however, I guess I was able to release my stress to some extent. I think you should always have an escape available.

I derive joy from my research because it’s enjoyable—that’s all I can say about it. Maybe I was born to do what I’m doing now. Because I find my work interesting, whatever I am doing—taking a bath or in bed—I find myself thinking about it spontaneously. So, I end up thinking about my research all the time.

Nishimura　Before we leave, I’d like to ask you if there is anything that you didn’t see when you were younger but began to see as you gained more research experiences and you place focus on.

Kunitake　When you are young, you put a lot of focus on one thing, but, as you experience various things, your view broadens. On the other hand, as the scope of your interest widens, it becomes harder to maintain a keen interest in individual things. If you try focusing your attention, however, I’m sure you can train your awareness of pertinent issues.

Sugimoto　I hear you liked reading as a child and often listened to vinyl records when you were doing research in the United States. In retrospect, do you think having such a broad range of interests had a favorable impact on your research work?

Kunitake　Being a post-doctor living alone in the States, I had a lot of free time. In Philadelphia, where I was a graduate student, they had a wonderful orchestra and a brilliant conductor by the name of Eugene Ormandy.^*4 I often went to see them play and bought lots of vinyl records. A friend of mine back then was really into music, and he taught me a lot about it, which prompted me to listen to various music genres, from classical to jazz and rock. I think music had a very positive impact on my cognition.

Listening to music, rather than thinking hard only about research, frees your consciousness. In other words, it gives you an opportunity to think flexibly. Well, it may spoil things if I try to give reason to all my choices.

Nishimura　You said you’re still 20-30% active as a researcher. What would you like to do next?

Kunitake　To bring the technology of huge nanomembranes, which I mentioned before, to the market, a venture business called NanoMembrane Technologies, Inc.^＊5 was established. In October 2020, this project was adopted as a Moonshot Research & Development Program by the Japanese Government for a period of ten years. At present, NanoMembrane Technologies and Kyushu University are jointly working on technological development for CO₂ capture from air. I hope to remain involved in this project for at least several years to come.

Nishimura　Thank you very much.

＊1. interface　A boundary where two phases with a different nature (solids, liquids, gases, etc) make contact.

＊2. alkyl chain　An alkyl group formed by removing one hydrogen from the alkane chain, such as methane (CH₄), ethane (C₂H₆), and propane (C₃H₈).

＊3. macroscopic nanomembrane　The world’s first self-supporting membrane that combines ultimate thinness of 30 nm and a macroscopic area of several centimeters square or more. Its applications in a broad range of fields, such as biotechnology, energy, and the environment, are expected.

＊4. Eugene Ormandy　A conductor born in Budapest, Hungary, in 1899. Appointed a music director of the Philadelphia Orchestra in 1938. One of the creators of the smoothly lush tones known as “Philadelphia Sound.”

＊5. NanoMembrane Technologies, Inc.　Established in 2007 to realize the practical application of the technology for macroscopic nanomembranes, discovery of RIKEN, Japan.

Click below to watch the YouTube video of Dr. Kunitake’s Commemorative Lecture from 2015.

[About the interviewer]
Yuya Nishimura
Executive Director, MIRATUKU. Earned a Master’s Degree from the Osaka University Graduate School of Human Science. Built a cross-sector -business and -domain innovation platform, supports leading companies (about 30 annually) in creating new businesses, assists launch of R&D projects, designs future visions, and searches for future trends. Other positions include Innovation Designer, Innovation Design Office, RIKEN, Japan, and Specially Appointed Associate Professor, Social Solution Initiative (SSI), Osaka University　 MIRATUKU website

[About the writer]
Kyoko Sugimoto
Freelance writer. Earned a Master Degree in Media, Journalism & Communication, Graduate School of Letters, Doshisha University. Interviews researchers, business managers, Buddhist monks, urban designers on such topics as asylums, communities, and Buddhism. Authored Kyodaiteki Bunka Jiten: Jiyu to Kaosu no Seitaikei (Kyoto University Cultural Encyclopedia: Ecosystem of Freedom and Chaos), Film Art, Inc.　 writin’room