Sciences : histoire orale

HIRAO Kazuyuki, 2002-08-29

Sophie Jourdin — 2011-11-04T13:08:55Z

Kazuyuki Hirao.

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HERVE ARRIBART (HA) : In which discipline did you take your degree and your Ph.D.?

KAZUYUKI HIRAO (KH) : I was trained in Inorganic Chemistry.

BERNADETTE BENSAUDE-VINCENT (BBV) : Why did you decide to go into Glass Science ?

KH : Well, you know, the Chemistry Department of Kyoto University is very old, 100 years old. When I had to select a laboratory, I was interested in inorganic chemistry. I belonged to the Chemistry Department but only one division of chemistry was Glass or Ceramics related to inorganic chemistry.

BBV : Did you publish books in inorganic chemistry ?

KH : Yes, I published two textbooks on Inorganic Chemistry intended for undergraduates. One of the textbooks was translated but another one I wrote myself in Japanese.

BBV : Do you have to teach inorganic chemistry ?

KH : Yes at the undergraduate level.

BBV : And do you have to teach a course in Materials Science ?

KH : Yes I have 3 courses a week : one of them is Glass Science, the second is Advanced Materials, and the 3rd one is Inorganic Chemistry. Inorganic Chemistry for undergraduate students, Glass science and Advanced Materials for graduate students.

BBV : There is no department of Materials Science at Kyoto University ?

KH : Materials Science partly belongs to chemistry. My department is called Department of Materials Chemistry. But Materials also belongs to Metallurgy. They have a department of Materials Science which is totally separated from us. We have no common class between Materials Science for chemists and Materials Science for metallurgy. We have to collaborate in the future. The Department of Materials Science also belongs to the Department of Mechanics. Chemistry and Mechanics are totally different. Polymer Chemistry is also separated. We still have to build up the new class of Materials Science. In Japanese universities, it is not usual to have interdisciplinary Materials Centers. It is usually divided. It is not good for research. Because equipment is shared.

HA : What kind of instruments ?

KH : TEM, SEM, X Ray, spectroscopy. At least in nanotechnology we ignore the boundaries between polymer science, metals, ceramics and glass. It will be possible to develop the new materials perspective.

BBV : Do you think that this traditional university system prevents you from doing Materials Science ?

KH : It is difficult to change. If you want to change anything, you will have to obtain agreements from all the professors in our departments. University professors are very conservative.

HA : Still, Professor Soga did endeavor to change the system while he was here.

KH : Yes, but in Japan if one single professor is against the change, then there will be no change at all. We don't usually have a majority decision making system.

BBV : Are the students more attracted by Materials Science in general or by Chemistry and Physics ?

KH : The entrance examination is about Industrial Chemistry. Almost 250 students are admitted. After one year, in the 2nd grade, they will be distributed into three different courses. Three classes divided mechanically. In the 4th grade they chose to enter into one the laboratories of the department. Four graduate students choose to enter in my laboratory every year. Kyoto University is a very big university. We have almost 47 chemistry professors for 250 students. 150 graduate students. Two Nobel Prizes came out from this department. It is a prestigious department.

HA : Could we come back to your PhD subject ? How did you choose it ? Was it Professor Soga who proposed it ?

KH : Yes it was about Glass Science. Thermal properties of glass.

HA : From your list of publications I can see that you have worked on many, many fieldswhile working in Professor Soga's laboratory.

KH : Yes I have been mainly interested in computer simulation of making glass structure and predicting optical properties of glass. I started computer simulation early in the 1980s. It was too early. The computer capacity was very small in the 1980s. Now we have a big project on computer simulation program and we get $5 million over five years from the government for it. Owing to the progress of computers, we can make glass structure containing 10,000 atoms.

HA : Then why did you move to non-linear optics instead of mechanical properties or low temperature behavior ?

KH : It is a good point. One major advantage of glass is transparency. Its major disadvantage is brittleness. Optical fibers are a very important because electrical wires are very limited in speed.

HA : So by the end of the 1980s you guessed that the future of glass for a large application would be optical glasses.

KH : Now we are very lucky. We are also interested in the mechanical properties of glass at the nanolevel. We are dealing with elimination of the nanobubbles. It is very important for industrial companies.

HA : So you got in to the glass making process ?

KH : Yes.

BBV : Was it industrial demand that prompted you to work on optical properties in the 1980s ? Or was it your own initiative, your choice ?

KH : In this period the optical properties were not important for glass industry. Now many glass companies are interested. So now we have a lot of industrial contacts. Before next year we intend to produce 3 commercial optical glasses called photonic glasses. For this, we need connections with venture business.

BBV : Do you mean that you conducted all these researches on optical properties without industrial support ?

KH : No, only in the beginning. Now we get a lot of industrial support. But now I get a lot of budgets from three kinds of government projects, not only from industry. We have 3 projects. One is computer simulation. One is on photoactive glass in cooperation with foreign countries. So we have a lot of post-docs in my laboratory. The third one is the nanoglass project.

HA : Could you tell us about this nanoglass project ?

KH : The government launched a nanotech program that covers a variety of projects : nanometals , nanopolymers, carbon nanotubes, nanocoatings, nanoparticles, nanosimulation and the nanoglass project. For the latter, we get $30 million for 5 years approximately.

HA : How do you spend this amount of money.

KH : Most people involved in the glass project are coming from industry, from Asahi Glass, Hoya, Nippon Electric Glass, Central Glass, Okamoto Glass, Nippon Yamamura Glass, Hitachi, ... 11 companies sent us 15 researchers whose salaries are paid by the project.

HA : How many people are working in your nanoglass project ?

KH : 100 people including the supporters. They join in Tsukuba consortium, from Osaka Institute and several university professors also support us.We have some large equipment.

HA : When did this project start ?

KH : We had a preliminary year and the project itself started in 2001.We have got a number of results. For instance CVD deposition. We also succeed in making very low optical loss glasses. We have reached 0.005dB/cm. This glass will be very useful for making waveguides. In Tsukuba we use two kinds of femtosecond lasers working at 1 kHz and 200 kHz. By using these femtosecond lasers, we not only write in waveguides but also we make crystals from glass, for example silicon crystals from amorphous silica.

HA : Last time you mentioned that you also have a laboratory in China working on crystal growth.

KH : That is right. And we have also made a lot of semiconductors, single crystals in glasses by using this material and we made photonic crystals, which can be used as optical filters.

HA : Where does the money for this nanoglass project come from ?

KH : From NEDO. It is part of METI (Ministry of Economy, Trade and Industry). No connection with AIST although METI also supports AIST. We also made a very tough glass whose strength is very high, 2 times that of standard glass. With the femtosecond laser we made very small dots, nanosize dots, that stop the cracks. We have already succeed.

HA : Was it enough to make these tiny holes on the surface ?

KH : They are under the surface. Also by using the interference technique we have made a lot of dots.

HA : I understand, it is beautiful glass but too costly for bottle makers.

KH : Of course it is not for bottle makers ! Also we have found a cheap process to make AWG (array wave-guide grating) by using the femtosecond laser. AWG are very useful for optical telecommunications. Until now, they were very expensive to make. We also managed to make a nanoglass thin film for CD. The storage medium can be a cobalt oxide-based glass, for example. When we apply a nanoglass coating on this recording material the blue beam is shrinked to ¼. This is a lens effect. We have now this optical disk standardized by Hitachi. So you know that Shuji Nakamura ; a Japanese researcher, has discovered the blue laser diode. In my case by using this blue laser diode, the recording capacity is approximately increased by a factor 4, because the beam is much smaller. And in the field of optoelectronics, we have made 3 dimensional devices including both electrical and optical circuits. We use gold containing glasses that crystallize under laser beam. Three dimensional wires can be obtained, together with optical waveguides in the same device.

HA : So this program seems to be essentially telecommunication oriented.

KH : Yes NEDO asked us to make such devices. Otherwise they would cut the financial support.

BBV : You mean that the budget is according to your practical results.

KH : Yes.

BBV : What kind of connections do you have with venture business ?

KH : For optical properties we have to make such connections. Otherwise we could not do it on university money or government money. Venture business have a lot of demands in optical properties of glasses. For instance some fibermakers make lenses inside optical fibers. With my technique of femtosecond laser we can make lense in fiber. There are many such innovations of interest for business, although optical properties are not directly related to optical devices.

BBV : Do you mean that you only do research and no development ?

KH : Optical properties are synchronized with optical devices. There is no linear sequence from optical properties to technical devices, from basic research to applied science then development. We have to work in synergy.

HA : So do you consider yourself as a materials scientist because you are dealing with devices ?

KH : Yes we have to make connections with venture business and industry. For doing this kind of research we have to build a wide network. So many venture businesses are connected with me and they are eager to be.

HA : Where does the money come from ? From big industrial companies ?

KH : So far my devices did not cost much. If one day we have to develop a costly device, the Japanese governement is able to support us immediately, at least for two or 3 years. The Japanese governement is encouraging this kind of cooperation.

HA : Do you also collaborate with foreign companies ?

KH : With Schott in Germany. They have sent a researcher here. And Corning is also willing to collaborate. In the USA glass professors are not so many in optical devices. Here we have more than 50 professors of Glass Science

BBV : Do you send students to the USA ?

KH : Not right now.

HA : Where do you locate the leading centers in your field ?

KH : I guess Osaka is the center. Glass science originated in Osaka National Center.

HA : You told me last year that you run many laboratories. How many ?

KH : I have 6 laboratories including one in China, one in Osaka, one Tsukuba ... 300 people altogether. There are autonomous and eager to make things because optical devices is a very promising field. So I don't have to be continuously behind them. There are so many things to do such as inkjet using semiconducting cadmium selenide nanoparticles. The color changes depending on particle size.

HA : This is not glass. Is it ?

KH : Yes it is, because nanoparticle CdSe particles are made in micelles and encapsuled by glass using sol-gel chemistry. The fluorescent yield increases nearly 10times using these nanoparticles. Silica sol-gel coating is necessary ; otherwise the semiconductor particles aggregate to each other. Encapsulated particles are then deposited by inkjet to make displays. We do this development by collaborating with venture business.

BBV : So you seem to work as a partner of venture business, as a manager of projects rather than as a traditional scientist supplying science for applications downstream.

KH : Yes my aim is really to make optical devices. This is what we have to do. We teach Glass Science. But in laboratory research we have to make devices. Traditional professors are not interested in devices ; I am. But you see, in Japan I don't have to move to an industrial company to make such devices.

BBV : Is it part of your obligations as a university professor to make devices ?

KH : No, teaching is the only obligation. We just have to teach and take care of the students.

BBV : Does the university system recognize your devices ?

KH : Yes now the government recognizes patents.

HA : So you feel that you are in a better position at the university because you have the freedom of choosing your topics of research and you have the money that you need for them.

KH : Yes I am very lucky.

BBV : How do you select your research projects ?

KH : The keywords are glass and optics. We have a lot of choices. One criterium is to use the femtosecond laser.

HA : You mean that you can use it to change glass composition ?

KH : If we use samarium doped glasses we can change the samarium3+ to samarium2+ with the femtosecond laser. So glass composition is very important for me. Not just to make new glasses and measure their optical properties. If we make a new glass it is to make a new device by using a new technique. We also made electrical lithography by plasma etching for nanodevices, in Osaka.

HA : On our webpage you also mention that you are working on hybrid materials.

KH : Yes usually at the macroscale, it is difficult to combine organic and inorganic components. Nanohybrids work better by using chemical reactions with micelles. Professor Tetsuo Yazawa at Himeji Institute of Technology University made a lot of nanohybrids that can be used for gas filters, for membranes, solid sensors and solid electrolytes. Conductivity is very high in the nanohybrids. Both electronic and ionic conductivities. And hybrids are also useful for glass capsules for drug delivery. So we started that kind of research on hybrids within the nanoglass project.

BBV : Do you try to compete with other materials in your nanoglass project ?

KH : No, glass offers unique advantages. We can overcome polymers. Glass is the only transparent material even at the nanoscale. I forgot ! Athermal glass is very important. We achieved athermal glass-ceramics we have to apply pressure to control the size of the nanoparticles and the growth. So nanoglass is unique and very useful.

HA : I can see that your project works very well. But do you remember any failure in your research career ? It is also instructive for our project on the history of Materials Science.

KH : For the Photoncraft project we are at the middle point so we have to submit. The nanoglass project started one year ago. We have to make an effort, otherwise budget might be cut.

HA : This morning Professor Soga told us that he considers himself as an educator rather than as a glass scientist. Is teaching and training also important for you ?

KH : You cannot separate teaching and research. Education and laboratory work together. In the field of glass, just making optical devices is a good education, a good training. Now we are training a number of students through the nanoglass project.

BBV : Do you mean that the nanoglass project is in itself a kind of training ?

KH : Yes, for graduate students. When I present the results of our nanoglass project to company presidents, they are essentially grateful for our work as educators because we train the researchers from industrial companies. Helping each other is very important.

HA : Does it mean that you are no longer interested in basic research and basic education ?

KH : No. Presently I am making devices but maybe in a few years I write a new textbook of glass science because they are so many new glasses that all conventional glasses are obsolete. This textbook should be written in English.

BBV : You want to write a textbook of Glass Science, not of Materials Science in general ? Are there any Japanese textbooks of Materials Science ?

KH : Yes and we had written one.

BBV : One final question : Do you see differences in the research styles of various countries ?

KH : In Europe originality is important. Here it is rather collaboration and harmony. We are more modest, more humble. Collaborations, mutual help and mutual learning, Interdiscipinary philosophy is my project aim.

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« Entretien avec Kazuyuki Hirao », par Bernadette Bensaude-Vincent et Hervé Arribart, 29 aout 2002 Sciences : histoire orale, https://sho.spip.espci.fr/spip.php?article125.

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Entretien avec Kazuyuki Hirao, par Bernadette Bensaude-Vincent et Hervé Arribart, 29 aout 2002

Lieu : Department of Materials Chemistry, Kyoto University

Support : enregistrement non précisé

Transcription : Bernadette Bensaude-Vincent et Hervé Arribart

Edition en ligne : Sophie Jourdin

ENDO Morinobu, 2002-08-26

Sacha Loeve — 2011-06-07T20:19:40Z

Morinobu Endo, né en 1946, est Professeur à la Faculté d'Ingénierie de l'Université de Shinshu à Nagano (Japon). Après un Master's degree à l'Université de Shinshu, et une Thèse en ingénierie à l'Université de Nagoya, il intègre l'université de Shinshu comme chercheur, Professeur associé puis Professeur en 1990. Il y fonde un laboratoire au sein du Department of electrical and electronic engineering. Ses recherches sont dédiées au carbone sous ses diverses formes ; elles vont du fondamental (propriétés physico-chimiques du carbone dans ses multiples formes allotropiques : graphite, nanotubes, carbone nanoporeux) à l'appliqué (fibres de carbone, composés d'insertion au graphite pour batteries et condensateurs). Morinobu Endo est notamment un pionnier des nanotubes de carbone (caractérisés en 1974 lors d'un travail effectué en collaboration avec Agnès Oberlin en France à la Faculté des sciences de l'Université d'Orléans). Ainsi en 1991, date généralement retenue pour la découverte des NTCs par Sumio Iijima, Morinobu Endo avait déjà développé et breveté un processus de fabrication donnant lieu à des usages industriels des NTCs comme composés d'insertion dans des accumulateurs lithium-ion (batteries d'usage courant pour l'électronique portable). Morinobu Endo a co-dirigé des initiatives pour la coopération université/industrie au sein de la Japan society for the promotion of science (JSPS). Depuis 2004, il préside la TANSO (Japan society of carbon). Membre du comité de rédaction de la revue Carbon, il est auteur d'une trentaine de livres sur la science du carbone et de plus de deux cent articles. Ses recherches lui ont valu de nombreuses distinctions : Carbon society of Japan Award, (1995) ; Charles E. Pettinos Award (American carbon society, 2001) ; Lee Hsun lecture series Award (Institute of metal research of China, 2002) ; ShinMai Award (Shinmai Bunka foundation, Japon, 2003) ; Ishikawa Award (Ishikawa carbon science and technology promotion foundation, 2003) ; Medal of achievement in carbon science and technology pour la découverte et la synthèse des nanotubes en 1974 (American carbon society, 2004) ; The Minister of education, culture, sports, science and technology prize for contribution to intellectual Cluster (Japon, 2005) ; Honorary citizen of Suzaka-city (2006) ; Small Times magazine best of small tech lifetime achievement Award (2006) ; JPA lectureship Award (2007).

BERNADETTE BENSAUDE-VINCENT (BBV) : In which discipline did you take your degree, and your PhD ?

MORINOBU ENDO (ME) : I started 30 years ago. I graduated from Shinshu University in 1971. Then took a Master in Electronics. I spent one year in a company, Statch. Then I came in this university in 1972 as a Research Associate.

BBV : So you spent your entire career in this University. How and when did you come into carbon science ?

ME : I became interested in carbon as a research assistant. At that time, carbon was considered as a dirty, dusty science, in comparison with the more attractive semiconductor science. But I found it promising.

BBV : Were there people already working on carbon here in the early 1970s ?

ME : Yes my professor Tsumeo Koyama was working on carbon. He was aged already but he asked me to incorporate here.

BBV : Why did you find carbon so promising ?

ME : I read a few pioneering papers by S. Mrozowski and by M. S. Dresselhaus. This encouraged me. At that time, there was an activity in carbon fibers based on Polyacrylonitrile (PAN) for aerospace industry. Industrial companies were most active in this field, especially Toray. There was a concern for new methods for preparing this promising material because PAN-based fibers were high-cost fibers. Professor Koyama asked me to prepare carbon fiber from vapor. This is a carbon fiber directly grown from the decomposition of hydrocarbons such as benzene. Vapor Grown Carbon Fibers (VGCFs) were totally different from the commercial PAN fibers. PAN Fibers are continuous while VGCFs are shorter. They have a unique structure. In the early 1970s I was able to prepare the fiber without understanding the mechanism at work, or what elements were essential.

BBV : So you had the technique but no knowledge of its structure and properties.

ME : Fortunately I had a chance to work in France with Madame Agnès Oberlin at the CNRS in Orléans.

BBV : How did you come in contact with her ?

ME : When I was a Research Associate in this university, I wrote a paper in Japanese showing that very beautiful carbon fibers can be grown by gas pyrolysis. A nice Japanese professor who was a good friend of hers, introduced my work to her. He invited her in Japan as a visiting professor and she asked to meet with me. I traveled to France with my fiber in 1974 and I worked in her laboratory for one year. In Orléans they had an electron microscope in 1973. I found that there were small opaque particles at the tip of the fibre (figure 1). In order to use the electron microscope it was necessary to use very thin fibers. For that it was convenient to stop the growth process at an early stage. I thus found that the fiber had an hollow core and later in the growth process the diameter of the fiber increased. Here on this picture you can see the particle. I found with Agnès Oberlin that this particle was iron. This result was published in France in 1976 in a paper entitled “Filamentous Growth of Carbon Through Benzene Compounds” (Journal of Crystal Growth 32 (1976) 335). In this paper we argued that VGCF had a “hollow core” which is the strongest part of the fiber. It never breaks when the fiber breaks. Sometimes you have cross-linkings of the fibers. Here just at the center of the fiber you can see the single wall nanotube (figure 2).

Figure 1. “Hollow core” in a vapor grown carbon fiber, 1976

Courtesy of Morinobu Endo.

Figure 2. Cross-linked single-wall nanotubes, 1976

Courtesy of Morinobu Endo.

BBV : Nanotubes ? You did not name it as such in 1976 ?

ME : We called it “hollow core” or “central tube”. Here you can see the fine particles at the tip (figure 3). By using bright- and dark-field image I found that they were Fe3C. This is the chemical product after cooling. At the end of the growth the particles should be iron. I suggested a growth model : the fiber first forms over this fine particles of iron then grow in the radial directions.

Figure 3. “Central tube” in the core of a vapor grown carbon fiber, 1976

According to Dr. Endo, this “central tube” is a double-layered carbon nanotube. Courtesy of Morinobu Endo.

BBV : Where this iron came from ?

ME : We were able to understand where it came from. We used a special sand-paper as a substrate. Without this sand-paper, no fiber. With this sand-paper that we used in France, we got beautiful fibers. We analyzed the electron barriers and we found that it was Fe2O3. Iron oxide coming from the sand-paper proved to be very important as a catalyst to generate the carbon fiber.

BBV : So you understood the mechanism when you came back to Japan ?

ME : I came back in 1975. I clearly described how the fiber grows, including the seeding methods, in a paper published in 1988, “Grow Carbon Fibers in the Vapor Phase” (American Chemical Society - ChemTech 18 (1988) 568-576). In a way this fiber grows in two steps : 1) this very thin fiber, the hollow core ; 2) the secondary process is the thickening of the fiber.

BBV : Do you mean that it took you about 10 years to understand the process ?

ME : No in 1988 it was already established. It is a review paper. So we put the small particle on a substrate (we used a ferrocene). Then we can grow that fiber as you can see on the screen (figure 4). As a result we got this very nice fiber. From an academic point of view, it was a full success because I was able to grow the fiber, to reproduce the product (there were many observations of such fibers but nobody could reproduce them). I clarified the growth mechanism – that the small iron particle acted as a catalyst for the decomposition of hydrocarbon, that the thin hollow tube grew then thickens to a carbon fiber. As a result we got a fiber with a diameter similar to that of the PAN fibers prepared by Toray.

Figure 4. Endo's vapor grown carbon fibers

Courtesy of Morinobu Endo.

BBV : Did you collaborate with industry in these years ?

ME : Yes we had collaborations. Showa Denko tried to develop this VGCF. But its productivity was very low. Because we put a substrate the growth rate was too slow. We tried to reduce the cost by using a continuous process. But in the same period the cost of the PAN fibers was drastically reduced so that we could not compete. Our VGCF are just beautiful fibers.

There had to be a breakthrough.

BBV : What kind of breakthrough ?

ME : I developed another method. This is the Endo-Japanese patent. I introduced the catalytic particles, which are derived from organic-metallic compounds such as ferrocene, into the reactor, in the three dimensions. The main difference is that there is no substrate. Here in this region, the particle reacts with the hydrocarbon and makes the hollow tube (figure 5). On the hollow tube then the deposition takes place. The process is in hysteresis. As a result we can get another type of fiber. It is totally different. This one is very competitve and commercialized.

I should add that at the early stage of the growth of the fiber, this is a carbon nanotube grown by a catalytic process. So it is now possible to grow carbon nanotubes by this method.

Figure 5. The Endo-Japanese patent, 1987

Courtesy of Morinobu Endo.

BBV : So you have already answered my next question : “How did you move from carbon fibers to carbon nanotubes ?” In fact, you prepared carbon nanotubes before this name came into use.

ME : We used to say “hollow core”. I get a little bit irritated about how the story is told. Here are my laboratory notebooks written in France (1974-75). Agnès Oberlin signed them. You can see a two-layered carbon nanotube. This is the TEM (Transmission Electron Microscope) photograph. I envisaged the possibility of very thin carbon nanotubes. Here you can read “mince cylindres” (thin cylinders). We had found the possibility of very tiny tubular structures.

BBV : Why did Mrs Oberlin signed this notebook in 2002 ? Was there a priority controversy ?

ME : Because I visited her in France last June. And because people said you should get the evidence that you had observed such nanotubes in 1975.

BBV : So nanotube was not discovered in 1991 by S. Iijima in his paper in Nature as people usually say..

ME : People say that Iijima clarified the structure of nanotubes. But Endo observed them in 1974. This is a recent understanding. I clarified the growth mechanism and the mass-production of a thick fiber out of a very thin cylinder.

BBV : The irony is that I came in touch with you through MIT thanks to Millie Dresselhaus and not through your French connection although I live in France.

ME : Mrs Oberlin lives near Montpellier in a mountainous area. She is now 75 year old. She gave me many evidences that I observed nanotubes in 1975.

BBV : Do you also know Bernier in Montpellier ?

ME : I know him but I am not as friendly with him as with Mrs Oberlin. He is a newcomer in science while I have been in carbon science for 30 years.

In my process the carbon nanotube is essential to grow the fiber but we can easily extrude the carbon nanotube. Now we can easily expand the technology to make carbon nanotubes. Several companies such as Showa Denko manufacture carbon nanotubes based on my method. Recently in order to make electronic circuit with carbon nanotubes people used this catalytic process. They put the small particle of iron on the electrode and expose this substrate to hydrocarbon to grow the nanotube. Here is a nanotube paper I am not too happy with ; they don't cite my old paper. Many people are not fair. They only take into account recent science and never go back to older papers…

Anyway this catalytic process is now applied in the mass-production of carbon nanotubes, whether they have single wall or double wall. To me it is very important to produce carbon nanotube and use them for practical applications. So coming back to your question about the date of discovery of nanotubes : in 1975 there was no practical use of carbon nanotubes. The interest was in carbon fibers. So we designed a process to get a thicker fiber.

BBV : When did the interest shift from fibers to nanotubes ?

ME : Carbon nanotubes quickly developed after the discovery of C60 in 1985. But they still have no practical application because they are still high cost. For carbon fibers, by contrast, we already had the technology, the know how to produce them. However my nanotubes are already commercialized for Lithium ion batteries since the late 1980s (figure 6). It is useful to provide safe small-size batteries for mobiles and camcorders. For safety reasons it is better to use only Li+ instead of metallic lithium. For this, we need to intercalate carbon at the anode. Almost most of the Lithium ion batteries manufactured in this country use my fiber in the anode. It is the only material that can work in this application. There is no alternative, no substitutional material. Only my product. So finally what the Japanese companies produce is based on my carbon nanotube.

Figure 6. Mass-producing and commercializing Multi-wall carbon nanotubes since 1988

Courtesy of Morinobu Endo.

BBV : Which Japanese companies manufacture the Li-ion batteries with your patent ?

EM : Many companies (Sony, etc). But, now this is not my patent. It is the company who manufactures my fiber who owns the patent. Only the production system is my patent. And I am happy with that. Even French companies like Alcatel who have a battery division need to use my fiber. Recently we got the allowance to export this material abroad. The Ministry of Industry (MITI) gave us permission to export this material. Now Alcatel and a number of American companies can use my material.

BBV : Do you mean that a Japanese company cannot export one its products without permission from the Ministry of Industry ?

ME : It is only for strategic materials with potential military applications because it is a strategic material for military uses (although I don't know which one). In such cases we are under the control of ICOCOM. Anywhere we can get such allowance.

BBV : Coming back to the earlier period of carbon science, what was your reaction and the reaction of your colleagues in 1985 to Curl's, Smalley's and Kroto's paper on the fullerene structure ?

ME : I felt very nice because it was familiar to me. I was very excited with that kind of nanosize particles.

BBV : After this publication did you get more funds to start research programs on nanotechnologies ?

ME : There was an impulse to work on nanotechnology. And the government gave us substantial funds. 95% of the research budget went to nanotechnologies.

BBV : If you get such substantial funds from government do you also have support from industrial companies ?

ME : Most of my research is supported by industrial companies. Only a small part of the basic science is supported by MITI. For carbon nanotubes we work in close collaboration with industrial companies. We have a very nice cooperation. We are always aware of pratical purposes. So in my research science and applications are closely intertwinned. It is our policy.

BBV : But industrial companies have their own research laboratories ?

ME : Yes, we collaborate with them. Presently I have about 100 collaborators who run joint projects with me. More exactly, I should say 50 researchers who come to join me. It becomes big science when you want to reach the commercial applications because you have to do all kinds of tests : safetyness, production cost, optimizing the size, the diameter of the fiber, its packing...It requires a lot of time and a lot of money. The PAN-fiber, for instance, was designed in 1965 and Toray spent more than 20 years of R&D before the commercialization of PAN fibers in the early 1990s. For the batteries we took 7 years.

BBV : Do you have a kind of division of labor with Research conducted in academic laboratories and development in industrial laboratories ?

ME : We have a lot of feedback. For any specific material we need a lot of time and money. Carbon fibers still need a lot of additional technology for commercial mass-production.

BBV : So your financial resources come both from industry and from government ?

ME : Fortunately we get a lot of money from industry because I contributed a lot to industrial applications. We also get money from the Ministry of education for scientific development. I am acting as a bridge between science and industry, and also as an interprter for tax-payers. We do a lot of coordination with social demand, between university and industry and also of education for industry. We are very busy.

BBV : In your career is there a close connection between teaching and research ? In particular how important was the book on carbon that you co-authored with Stan Mrozowski and Millie Dresselhaus ?

ME I have been deeply encouraged by Millie Dresselhaus. Our book was not intended as a textbook. Rather it was a review book. When it was published in 1996 most of the people were rather interested in fullerenes. This book triggered the interest in nanotubes. The publisher Pergamon is very active in carbon science.

BBV : As historians of science and technology, we learn a lot from success but failures are even more illuminating for us. Would you tell mes about a case of failure in your career or in your field ?

ME : I don't remember any project of mine which failed. I spend a lot of time selecting my research projects. It is important because lot of Japanese companies trust me. I have no right to fail. Every problem has a solution. In a sense the tiny cylinder of the nanotube is a miracle. How can we control particles at the nanosize !

Carbon is an old but new material. Professor Kroto who got the Nobel Prize in 1986 said in his Nobel address : the 21st century will be the century of carbon. I believe that. Carbon is a key material. Carbon fibers and carbon nanotubes are vital in three respects : for energy, fuel cells in particular ; for information technology (mobiles and computers) ; for environment, especially for the purification of air and water. The question of water is crucial : 2 million of people die every year from impure water and 20 million are sick from impure water.

BBV : How can you use carbon for the purification of water ?

ME : It is possible. We can use activated carbon to take off bacteria. Developing countries need clean water at a reasonable cost. So carbon is and will be in the future a key material. My own research is focussed on carbon nanotubes, their action, their preparation, growth mechanism, control of the structure and applications. We study batteries, new devices for energy storage in new cars, devices for water purification for the developing countries.

BBV : You mean that in one laboratory you can afford to conduct all these projects altogether ?

ME : Yes, as they are all related to carbon. Carbon and its properties are important everywhere. I'll show you a very nice table. Carbon is not the most abundant on the earth like silicon. It is only 0.04% of the material resources. But carbon is localized, concentrated in some places so that it is easily accessible and easy to extract.

BBV : How many people are working in your laboratory ?

ME : I have 25 people including students and post-doc. We have ten research projects. They come from materials science, electronics or electrical engineering, physics and two post-doc chemists.

BBV : Do you have financial constraints for the purchase of laboratory equipment ?

ME : We have few constraints to buy instruments. For instance, we have got a very sophisticated Transmission electron microscope, all computerized (figure 7). It is a unique model made by a Japanese instrument maker. It has three functions : EDX (Energy-dispersive X-ray spectroscopy), EELS (Electron energy loss spectroscopy), and Mapping.

Figure 7. Endo's Lab TEM

BBV : Did you acquire it with industrial funds or state money ?

ME : It was state money. We also have various analytic instruments for carbon materials such as STM (scanning tunnelling microscope), TGA (thermal gravimetric analysis), FE-SEM (Field emission scanning electron microscope), Thermal conductivity analyser, Raman, XRD (X-ray diffraction), pore distribution analyser, etc.

BBV : Do you have a lot of routine reporting to your sponsors ?

ME : We have obligations towards the university. The annual report mentions how much money I get from the Ministry of Education. But how much support I get from industry this is included in the global amount of subsidies provided to the university. The annual report does not mention openly how much Endo gets from industry. I think I am one of the most funded.

BBV : Publishing or patenting ? What is the priority ? Which one is the most important for the credit and reputation of a laboratory in materials research in this country ?

ME : It is now the Japanese policy that patenting and publishing should run parallel. For me publication is more important. But as part of the national community I should keep a balance between publications and patents. The Ministry of Education recognizes and rewards patents.

BBV : Do you file patents in your own name ?

ME : It depends. If the research project was financed with state money as a national project, then the patent is a state patent. If the patent comes out of a project financed by industry or by the university then it is your individual patent.

BBV : Who gets the royalties ? you or the university ?

ME : We have a judge who decides. If we invent a product with funds from the unviersity, most of the time it belongs to ourselves.

BBV : The patent on vapor deposition carbon fiber belongs to yourself ?

ME : Yes it is my patent.

BBV : Do you have international collaborations : in which countries ? How much do they matter ?

ME : With Millie Dresselhaus, it is a private collaboration. I also have collaborations with Sussex University (U.K.) and with Mexico. In France I have friends but no more collaborations.

BBV : Did you notice differences in the research styles of various countries ?

ME : I cannot see any difference in research styles. The Japanese style is very much americanized. Or rather, our style is between the French and the American styles.

BBV : What is the French style ? And how would you characterize the American style ?

ME : American style is top-down with the state at the top. French style is rather bottom-up. In Japan it is half-half. I feel rather close to the French style but for patenting we are more like the USA. In France it is difficult to file a patent.

BBV : You have spent 30 years on one single material, carbon. But do you think that the materials generic perspective with its basic notion of structure, properties, performances and process, is useful for your research ?

ME : I think that I have a very general concept of carbon. I generalized the concept from structures to properties. Process is very important to get up with the structure in the case of carbon. Carbon science developed by studying its structures but now processing is important. You get different structures with different processes.

BBV : What aspect is the more important for you ?

ME : I am neither a specialist in processing, nor a specialist of structures. I am a carbon scientist.

BBV : What is the place of materials science in general and carbon science in particular in Japan ?

ME : Unfortunately carbon is a minor field. Semiconductor is the major field. In the minor field of carbon I should say I am number 1 or number 2.

BBV : Does carbon science attract students ?

ME : Yes many students come to work with me, because we have advanced equipment and there are job opportunities in this country : in car companies or electric companies.

BBV : Where do you locate the leading centers in the field of carbon science ?

ME : The major countries are Japan, USA, France and Germany. Then come India, then China, England and Canada.

BBV : Do you see Japan as the leader ?

No. Japan, USA, France and Germany are at the front. It depends on the field. Certainly Japan produces 70% of the carbon fibers by the aerospace applications in the USA.

BBV : Where do you locate the strengths and weaknesses of Japan ?

ME : The human network is too strong. More open competition like in the USA would be necessary. In France the system is too centralized, too concentrated.

Fin de l'enregistrement

Pour citer l'entretien :

« Entretien avec Morinobu Endo », par Bernadette Bensaude-Vincent, 26 août 2002, Sciences : histoire orale, /spip.php ?article8.

Pour citer l'entretien :

« Entretien avec Morinobu Endo », par Bernadette Bensaude-Vincent, 26 août 2002, Sciences : histoire orale, https://sho.spip.espci.fr/spip.php?article8.

Lieu : bureau de Moronibu Endo, Endo lab, Université de Shinshu, Department of electrical and electronic engineering, Wakasoko, Nagano-shi 380-8553, Japon.

Support : enregistrement sur cassette.

Transcription : Bernadette Bensaude-Vincent.

Édition en ligne : Sacha Loeve.