Sciences : histoire orale

JORGENSEN Jans Friis, 2001-03-06

Sophie Jourdin — 2011-11-03T14:01:46Z

Jan Friis Jørgensen is the main developer of the Scanning Probe Image Processor or SPIP™, a computer program that processes the output from scanning probe microscopes. This program is currently the only one of its kind in the world, and sales figures are rising steeply. SPIP™ includes the visualization of image files and various other features such as auto-correlation and Fourier transforms. Add-on modules include calibration and roughness analysis.
An electrical engineer with an industrial PhD in scanning probe microscopy, Friis Jørgensen participated in the early developments of the scanning tunneling microscope in Denmark. Erik Lægsgaard built the first one in 1987 in collaboration with colleagues at the University of Aarhus (Flemming Besenbacher and Ivan Steensgaard). Towards the end of 1987, Danish Micro Engineering (DME) turned to the production of SPMs. Friis Jørgensen joined that company between 1989 and 1990. He then worked on an industrial PhD at IBM Denmark, and also spent 4 months at IBM Zurich. From 1993 to 1998 he worked at the Danish Institute of Fundamental Metrology (DFM), interrupted by a year at the National Institute of Science and Technology , just outside Washington, DC. In 1998 he founded a company called Image Metrology to market the program, honed on his experience in the previous decade. The company is located on the campus of the Danish Technical University, in the same building as DFM. In May 2001, the company acquired an additional location close by.
Since 1999, the company has participated in the European Network on the Calibration of Scanning Probe Microscopes, sponsored by the EU Commission. The purpose of this network is to establish a basis for the application of SPMs to metrology on the nanoscale.

ARNE HESSENBRUCH (AH) : Did you study physics ?

Jan Friis JORGENSEN (JFJ) : No, not at all, I am not a physicist. Many people think that I am, but actually I was educated in electrical engineering, got a master degree with a special within biomedical engineering. And I think I've worked around seven years within different fields of medical engineering, oral visuality and also all the sound diagnostics that we've took care. When I started in a small Danish company called DME, which is still existing, and producing STM, SPM, microscopes.

AH : When was this ?

JFJ : I think it was back in 89. I worked there for almost two years and in the beginning I was not meant to work on the STM, but they were behind schedule, so I was assigned to the project and I got stuck. I stayed there for almost two years.

AH : And you had never heard the STM before joining the company ?

JFJ : Not really.

AH : After joining and learning about the STM, what did it mean to you ? Was it an exciting instrument ?

JFJ : Sure, very exciting, it was new. It was very new that people could visualize atoms, achieve atomic resolution, so it was of course attractive to work with. But as a software engineer, you are a little bit of an outsider because all the good people were physicists. It was physicists who had invented the microscope ; nevertheless I recognised several problems in the microscope : even with very fine resolution there was much distortion in the images. Already at that time many people had tried to correct it - of course in hardware which is also the best way to do it if you can - but there are still many problems that could not be solved this way. So I thought why not ? But there was no time for such work in that company, there was not enough resources, and there were many other things to do. I got a chance to work on it only upon leaving the company in November 1990, when I started on an industrial Ph.D being hired by IBM Denmark and collaborating with the Danish Institute of Fundamental Metrology and the Danish Technical University, the Image Processing Department. I finished in 1993. I could almost define the project as I wanted. I had already had seven years of experience working in private companies. But now I had to study again, and of course that was hard but it was also good to know about all the problems which I wanted to solve. It was a kind of a niche, because, as I have said before, most people at that time were physicist working on it, and so they had different approaches for solving the problems, and I used my small capabilities to solve that.

AH : Could you elaborate on the problems ? The tip and sample overlap, is that the kind distortion we are talking about ?

JFJ : Well, that was the one distortion people had been very focused on : how well the tunneling process worked when scanning over the atoms and several people produced very good theories on how to understand these mechanisms, but when you were scanning over a hundred nanometers or more it didn't really matter. There were other sources of error in the equipment itself : the hysteresis of the scanner and of different kinds of noise in the operations. These were actually the main problems and I guess within science it was given too little attention. Of course it was more exciting to look at atoms.

AH : Was it a case of low and high status research ?

JFJ : I don't know, it might have been. Anyway I think I found a niche ; I solved some hysteresis problems in new ways that nobody had considered before. And it is a part of our living today.

AH : Are there more distortions ?

JFJ : You mentioned the tip-sample which is of course a problem. It is understandable that to measure something very small, the probe should be at least as small to get a good image.

AH : That's not an issue you can address with your tools, is it ?

JFJ : I can not address it today. At that time, when I made my Ph.D, I addressed the problem but I did not solve it, because I didn't have the time for it, but other people solved it in meanwhile - I mean as best as you can. With software you can do a little, but you can't make everything perfect. Nonetheless software helps you a lot. First of all, you need an understanding of the shape of the tip. Some tips are simply too poor to use for imaging but others are acceptable. With these I can use software for correction and reconstruction, and this can lead to more accurate measurements.

AH : Were you alone in your field ?

JFJ : There have been more papers on tip characterization and on understanding the tunnelling mechanism, while there have been few on hysteresis.

AH : But in your niche were you completely alone, or were there other people working on it, say around 1990, when you were doing your Ph.D.?

JFJ : There were a few working on metrology, but not with these automated image processing tools. I think at that time it was quite unique. There was nothing out there to copy, so I had to invent the tools myself.

AH : How did the opportunity to do an industrial Ph.D. come about ?

JFJ : There was an ad in Ingeniøren, a Danish periodical for engineers.

AH : Whose advert ?

JFJ : IBM Denmark and the Danish Institute of Fundamental Metrology.

AH : Was Kim Carneiro behind this ?

JFJ : Yes. I found it natural to also connect the Technical University to the project. So I ended up with three partners.

AH : The Ph.D topic was to write software to deal with the distortions in the machine itself, the noise coming from within ?

JFJ : Yes. Maybe there was also another approach, because there had been people before doing some software by making certain algorithms and demonstrating that it could work from the very beginning. I tried to enable others to use this and I built the house bigger and bigger. It's the still the same building but we have taken it from Unix to normal PCs to really reach many people. I also stayed also a couple of months at IBM in Rueschlikon where the STM and AFM was invented.

AH : When did you go there ?

JFJ : It must have been 91 or 92 - I don't remember exactly.

AH : Were they interested in your project ?

JFJ : Sure, sure.

AH : Did they also recognize it as a niche ?

JFJ : Yes, but there was also skepticism. Some said : "well, people have been making software before, but when they leave the software gets lost because nobody knows how to use it and continue to work on it."

AH : This is a general problem of software, right ? That it has to be made user friendily and to become independent of its maker.

JFJ : Yes. It's hard to get enough attention within a scientific institute I think, because their focus is on something else ; there are barriers. At the beginning only physicists worked with the STM and nanotechnology. Now there are physicists, chemists, biochemists, biologists - a lot of people who previously did not communicate. They need to learn from each other now. And you can not build an STM without using a lot of different sciences. One of which is of course software. But at that time, people were happy simply to see an image on the screen after pushing a few buttons.

AH : So the demand for your software has developed with the increasing expectations of what you could do with a STM ?

JFJ : Maybe, I think at the time nobody believed you could start a company based on image processing for scanning probe microscopy.

AH : Because the market for SPM was very small ?

JFJ : Very small, but when I finished in 93 I considered commercializing and I discussed it. Nobody believed in it.

AH : Now it is feasible to run this as a business because the market is large enough ?

JFJ : SPM is of course a niche but from a software engineer's point of view it's simply image processing. There's no shortage of images requiring treatment such as scanning electron microscope images and optical microscope images. We now have enough expertise to address the other markets too, so we kind of expand from the nanometer range of SPM to many other things around us.

AH : I would've expected the noise and distortion in other instruments to have been completely different so that you would not be able to draw on your expertise with SPMs.

JFJ : Many of our tools can be applied to other images. Some distortions are indeed peculiar to SPM images, but there are also some generalities. For instance, satellite images are scanned line by line the same way an STM image is, and this line by line scanning can give the same kind of distortions and artifacts in each type of image.

AH : I see ; that is indeed very general. As a physics student I scanned photographs of the solar surface using an optical photometer and of course it scanned in just this way. Interesting ! When you started your Ph.D., did you already think in terms of such generality ?

JFJ : Sure ! You have to. I mean I didn't go into the field to just to be an SPM person. I wanted to learn something which I could use widely. Of course the SPM is interesting in itself, but image processing is also interesting in itself.

AH : All right ; in 1993 you finished your Ph.D. What were your options then ? Could you have gone to IBM ?

JFJ : Probably yes ; I didn't really try. I didn't because I really wanted to stay in the field of STM. I think there was still a lot of work to do so I continued at DFM.

AH : What about the big STM companies like Digital Instruments and Park, could you have gone to them, were they interested ?

JFJ : At that time, I didn't have much contact with them, and they do not pay much attention to single individuals. You really have to scream loudly to get their attention. Of course they know me now ; I have visiting several such companies. I visited Digital Instruments back in the autumn of 99, and I gave my talk twice. The second one was in an R&D meeting and that brought me a lot of attention. There is potential for some cooperation with them. Actually we have a non-disclosure agreement with them to solve their instruments' hysteresis problem. But they act slowly.

AH : What was attractive about DFM for you after the Ph.D ?

JFJ : That I could continue the work on image processing within the same field, SPM. Also, while working on SPM, I looked for a post-doc position. I finally found one at the [U.S.] National Institute of Science and Technology, which had relations with DFM, because both are metrological institutions. At NIST they also worked with SPM and I could do some image processing there. So, it was a very attractive position for me.

AH : Did they have a big outfit for STM problems at NIST ?

JFJ : Not that big, but they were working on what I would call a high risk project : a "molecular measure machine". The idea was to measure several milimeters across while keeping atomic resolution. At least atomic resolution it is very hard to measure even 100 nanometers across. In addition, they not only wanted atomic resolution but also to use interferometers and things like that in order to make all the accurate measurements. Of course, the more equipment you add, the heavier the construction and much can go wrong. So, it was a high risk project. I actually think it is still running. Obviously they have learned a lot by working on these complicated projects and I contributed a little software.

AH : How long were you at NIST ?

JFJ : One year. I came back and worked at DFM for almost two years.

AH : And you started your own company. Thinking about intellectual property, how have you managed this ? For example, write software at NIST, they presumably get the rights ? How does this work ?

JFJ : Well, I carried most of my software with me, so it was mostly a matter of porting it to run on their Sun machines. The difficulties centered on being able to read and handle their special file formats. So, I wouldn't claim that I made an invention while at NIST.

AH : The experience at NIST rather taught you something about generalizing your software to be used on various other systems.

JFJ : Yes.

AH : Presumably that is a continuous story now that you put it on Windows, as you mentioned.

JFJ : Yes, we jumped from Unix to Windows. The market for Unix was not that big even then and it is not really growing.

AH : So what did you learn from the NIST experience ? What did you take home ?

JFJ : Well, a lot of connections. Very often, the best you get is getting to know people and to discuss problems with them. I recognized some new problems within SPM I hadn't known about before, which of course leads to new ideas for solutions.

AH : For example ?

JFJ : We are getting deep into the way you scan. Scanning with a tip, you might have some friction making the tip bend. When scanning from left to right it bends one way, and when scanning from right to left it bends the other way. At the time most people thought that it was only in the AFM that you have these problems. Probably the most important thing I learnt was from their instrument that was more accurate than any I had ever seen before which enabled us to track very small residual errors. This showed me that the problem just mentioned is more general. We needed algorithms to improve the accuracy in order to measure at the sub-pixel level. Some of the algorithms which we have developed more recently for metrological systems are based on my experience at NIST.

AH : Let me make sure I understand. How would you know about the friction ? From a systematic difference in the scanning this way and scanning that way.

JFJ : Yes, you can see systematic dissimilarities between left to right and right to left.

AH : But that would only work if you stay in one line and just go to and fro, right ?

JFJ : You could do that but you can also take every second line. Usually, if you make an image, it's only from left to right. They were scanning one line left to right and then the second line back the other way, and you can address all kinds of different hysteresis problems. And if the lines are not aligned then you need to analyze how much the odd lines shifted compare to the even lines. That's very technical.

AH : But this would work only for a homogeneous surface, wouldn't it ? You know, if you have a very inhomogeneous surface where every line is different, you can't really tell what is the error and what is a sample, right ?

JFJ : Yes and no. The best thing is of course if you have something like a test structure on a homogeneous surface, but the closer the scan lines are together, the higher is the correlation, so by image processing and correlation techniques, you can actually correct for them. For instance, you can take every second line and make a cross relation and from that see that the line in between had been shifted, maybe just by 0.5 pixel.

AH : I see - and this shift is likely due to the bending of the tip scanning the sample surface ?

JFJ : You can hysteresis in more ways. You can have it in the piezo itself and indeed in other mechanical parts.

AH : And so what you have to do is to identify all the various kinds of hystereses and adjust ?

JFJ : All the non-linearities.

AH : Okay, let's get back to the chronology. The STM project continued at DFM after your post-doc ?

JFJ : Yes, I got a permanent position which included other tasks. I became head of the consultancy section. So, I was able to continue my image processing work, but only part time.

AH : Consultancy for whom ?

JFJ : Everybody who wanted to buy our services. So, of course, one service I wanted to sell was image processing.

AH : Any image processing ?

JFJ : Yes, but we particularly wanted to sell our SPM expertise. People who come to DFM to get some images of a surface and a report. We had a few jobs, and the number of these jobs have increased.

AH : I am curious about the volume of this demand over time, if you have a sense of it. You started in 95 ; presumably there were very few few companies in 95 asking for such services ? Actually, was it companies that came for your services or government bodies ?

JFJ : No, it was university research institutes. They are still the majority but more and more high-tech companies are now using SPMs.

AH : Do you have a sense of how many SPMs there were in Denmark in 1995 ?

JFJ : I think we arranged our first user meeting in 93 or 94. We were only 20 or so ; in 96 maybe 50 people attended our user meeting.

AH : And each person corresponds to one instrument ?

JFJ : No, no, it's hard to say, because each one of those people may have had five, six, seven, eight instruments, or even more. But still there weren't that many in Denmark and there aren't even today.

AH : Can you put a number on it ?

JFJ : No, it's hard for me to put a number on it. I know for certain that DFM has four which I use. One is shared with DTI, the Microelectronic Center and the physical department here have one. I am not actually sure whether it is in working order, but they will eventually build a new one.

AH : They will build a new one ? They don't buy off the shelf ?

JFJ : They build it or buy from the Aarhus group.

AH : The DFM services are for people who come with their data right ? They don't come with an STM, so that, say, you would build the software into their software package.

JFJ : No, we never did that. Of course there are many ways you can use USB expertise. But the kind of job I had was like the one where I simply received some images from a company in America and had to give some feedback on distortions and such things. So, they can bring images that I analyze. Other customers came with surfaces to be measured and analyzed. We SPM-recalled and analyzed.

AH : Working here at the DFM, did you use your software in real time, adjusting while the SPM scanned ? In other words, did you build the software into the SPM ? Or did you measure the data first, and then run the software on the data set ?

JFJ : I never got to build the software into SPM. Before I left for NIST, we had started a project at DME with the intention of integrating our hysteresis algorithms into their software but we never finished. I forget why, but it also had to do with my going to America.

AH : How much of the starting your own company was your own desire to do it and how much was the current pressures in academia ?

JFJ : There was no pressure

AH : None at all ?

JFJ : No, no. You have to fight for what you want.

AH : You wanted to start your own company ?

JFJ : Sure ! And nobody pushed, not at all.

AH : In that case, the market issue we broached briefly before must have been very important. The number of SPMs in existence must be a crucial one for you. But we talked only about the number of SPMs in Denmark, and obviously you want to sell globally.

JFJ : Oh yes. Denmark is very small market. We could almost exist without it.

AH : What precisely are you selling ? The service of unscrambling data or the software ? I have noticed that you do offer free downloads on your website. What's the business rationale for doing that ?

JFJ : Well, we are not doing any conventional marketing, so this is a actually crucial part of the marketing. People can go by themselves and find the product and try it and if they are happy, they might want to buy the full package.

AH : Okay, it's a test, it's a demo.

JFJ : It's a demo. It's very easy to give them the full version, we can just email them a key and they can implement it in ten minutes.

AH : Do you have any sense of how many people download this program ?

JFJ : Yes, around 2000 different people.

AH : 2000 downloaded demos ?

JFJ : Yes. We are preparing a release and once we have it, we will send an email out to to everyone who has downloaded in the past and then I will be able to update on our numbers. It has been a long time since I checked but I think it will be around two thousands.

AH : Presumably the idea is to sell new versions and upgrades ?

JFJ : We are working very gently with this. When they buy, they get one year of free upgrades. It's part of the deal that whenever we have improvements for the modules they bought we send them without further cost for the next year. This is big selling point because we are upgrading very fast. We don't want our customers to have an obsolete product.

AH : So this a long term business plan ? I mean, small businesses don't usually make a profit in the first year, and one couldn't expect that of you either ?

JFJ : That's true

AH : Are you in profit yet ?

JFJ : Yes, right now we are.

AH : Wow, that's great !

JFJ : We had some positive surprises in February [2001]. So, it's quite a good development ; it keeps us busy.

AH : How many people are you ?

JFJ : Only three. I have had a permanent employee for one year now and we have also been using some students who have since left. No we have three permanent people.

AH : And you are all software people ?

JFJ : Yes.

AH : No marketing people ?

JFJ : No, not yet.

AH : So that will happen ?

JFJ : Yes. It has always been part of our business plan. But the timing is not right now.

AH : How do you work out the business structure with the not-for profit institutions that you collaborate with ?

JFJ : It's not a problem. That's why we are here. It's definitely an advantage. It's most important for us to have somebody around us using the software heavily in their work.

AH : They can tell you about the troubleshooting ?

JFJ : Yes, but not only errors, also new ideas and feedback on what they need. That is very important to us and we encourage all of our customers to give us feedback. New ideas are often built into free upgrades.

AH : What's in it for the Danish Technical University to have you here ?

JFJ : I do not know. Of course, we are paying rent here and we can contribute to their visibility, showing that they are helping new companies. Actually, we are talking about the Danish Institute for Fundamental Metrology which is not a part of DTU. It's like DTI, a self-owned technological service institute ; most of their income stems from project money from the government. We have a license agreement with them. They get 5% of everything we sell and they are a part owner.

AH : Are they under pressure to show their relevance for Danish industry ? Is that what you meant by visibility ?

JFJ : Sure, if you can show that a successful company was spun off an academic or government institute the latter would have an easier time getting money later on.

AH : What competition have you got in this field of unscrambling SPM images ?

JFJ : I think we are probably the only company making software exclusively. There are some other companies selling software to go with hardware, the latter being their main business.

AH : Such as Thermo Microscopes, and Digital Instruments ?

JFJ : Thermo Microscopes are only selling software to their own customers, I think. There is a small Spanish company coming up with some software right now. So, I have to consider whether they are a competitor or not. When I started I expected my major competitor to come from the United States. Don Chernov has a company called Advanced. He had something and it was very expensive - it was still in the DOS world. I think it has changed since then and in this respect I don't really regard them as competitors. So right now we are sitting pretty and have only a few competitors. And for those people who really want accurate and serious measurements, the competition is very small.

AH : So you are not worried about people downloading and doing some reverse engineering and so on ?

JFJ : One should of course always pay attention to such issues.

AH : Thank you very much !

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Pour citer l'entretien :

« Entretien avec Jan Friis Jørgensen », par Arne Hessenbruch, 6 mars 2001, Sciences : histoire orale, https://sho.spip.espci.fr/spip.php?article119.

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Entretien avec Jan Friis Jørgensen, par Arne Hessenbruch, 6 mars 2001

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Transcription : Arne Hessenbruch

Edition en ligne : Sophie Jourdin

ARRIBART Hervé, 2001-02-19, 05-29, 02-20

Sophie Jourdin — 2011-06-16T07:31:17Z

Hervé Arribart is the Scientific Director of Saint-Gobain Recherche, an international company of French origin with an emphasis on glass manufacture. He took his PhD from the Ecole Polytechnique in Paris in the mid-1970s and subsequently researched ionic transport using nuclear magnetic resonance. In the late 1970s he worked with Jean Rouxel's group at the University of Nantes. In 1981 he joined the company Elf to work in research and development. In 1985 he moved to Saint-Gobain, where at first a large portion of his research was closely related to the practical problems of production. In 1990 he started a laboratory (a joint venture of Saint-Gobain and the CNRS) on the basic science of glass surfaces, using a diverse set of tools and especially the Atomic Force Microscope. In 1999 he moved to the more managerial position of Scientific Director. Hervé is also on the staff of this project.

2001-02-19 :

HERVE ARRIBART (HA) : I studied at the École Polytechnique in Paris. The selection to the school is done mainly on mathematics. But during my studies I learnt to appreciate physics in particular. I decided to pursue research in solid-state physics. It was a good place to study physics. While in my last year as an undergraduate I did a Diplome d'Étude Approfondie in parallel (an intermediary between an M.Sc. and a PhD typically done for a year before starting one's PhD studies). In Orsay, near the École Polytechnique, there is a very famous place in solid state physics, a lab started by Jacques Friedel - a great name in solid-state physics. I followed this course and afterwards I did the PhD at the École Polytechnique in the field of condensed matter physics. In principle I ought to have started with a topic distant from materials science. I extracted spin-polarized electrons from semiconductors. This was in 1974.

ARNE HESSENBRUCH (AH) : How did one extract spin-polarized electrons in 1974 ?

HA : It is true of all solids, but in semiconductors it is especially interesting that when light falls upon a surface there is a coupling between the spin of photons (in classical physics : the polarization of light) and the spin of electrons. Electrons in the upper layer absorb light photons depending upon the spin. If by some technique you can extract electrons from the conduction band of the semiconductor, you can find ways to select electrons of specific spins. This was quite important at the time because at big-science institutions such as LEP [Large Electron Positron collider] or SLAC [Stanford Linear Accelerator Center], there was a need for spin-polarized electrons. And of course you then needed solid-state physics to do it. But the man who in principle was my supervisor decided to do something else. His name is Claude Weisbuch, and he is now a good friend of mine. For a few years he was the scientific director of the French Department of Defense. He is still working in solid-state physics, in the optics of semiconductors. But he decided to do something else and Bernard Sapoval, another professor at the lab, proposed that I work on new materials. At that time there was little contact between solid-state physics and solid-state chemistry. The idea was to link up with chemists. This is why very early on in my career I had contact with chemists. We worked with Parisian solid state chemists on a new material. We found a new way to draw single crystals of an already existing material. It was very nice because we could examine transport and NMR phenomena. And the material, a copper vanadium sulfide exhibited astonishing properties : a large spread of conductivity that one can measure in a standard experiment. We suspected that this was due to mixed conduction properties. Mixed conductivity refers to conductivity by both electrons and ions. The experiment appeared to verify our a priori suspicion. This gave me the possibility to present a model for mixed conduction in this material and to understand the influence of ion transport and electron transport. I also used NMR in order to understand which ions moved. It turned out that the copper ions moved. So, this was the subject of my first thesis. At the time, in France, there were two theses. The first one was called "thèse de troisième cycle". The second was the "Docteur es sciences". This degree does not exist any longer. The thesis that is done now is shorter.

I decided to continue to work with chemists. I decided to combine NMR and transport measurements. I changed my collaborators, turning to two different groups. In my PhD there had been two chapters on NMR. But I wanted to study proton transport. I had two reasons. One was that protons give a strong NMR signal. The second reason was that two reasons had been given for proton transport. In one, protons move in individual jumps. In the other the proton is a part of a more complex molecule such as the ammonium ion (NH4+) or hydroxonium (H30+). In the former case we can see the transport phenomenon as a result of molecule rotation and proton jump. The molecule would turn and the proton jumps to the neighboring molecule, which again turns and so on. This was called the rotation-jump model. The second model was for the whole complex ion to jump. This was called the vehicle model because the whole molecule acts as a vehicle. So I worked with one group of chemists in Nantes, at the Institut de Matériaux de l'Université de Nantes. It had just been created by Jean Rouxel, a chemist. With them I worked on a substance called antimony acid - a solid. I was able to show using NMR that transport occurred in this case with rotation-jump. Protons used H30+ as a complex rotator. I was also able to show that the jump was due to quantum mechanics within a certain temperature range. It was not the usual ion transport of classical mechanics.

AH : A tunneling effect ?

HA : Yes, this is one aspect of protons, because protons are very light ions allowing for this quantum effect. The other material I studied was ammonium beta alumina. This was the standard beta aluminium in which the sodium had been ion exchanged with ammonium. This material was very interesting from the perspective of NMR. All kinds of ionic motion took place at different temperatures. At the lowest temperatures, that of liquid helium (1-4K), there was rotational quantum motion. As the temperature increases the motion becomes classical.

AH : If I may make a comparison with Stanley Whittingham here. You were working on some of the same materials, you were using some of the same tools (NMR), but you were asking very different questions, right ?

HA : Yes, that is true. I was not at all involved in the application. For two reasons : French chemists were interested in materials and did not look to the application. And chemists were between me and the application, so I had no contact with attitudes such as Whittingham's. I was very happy working on the solid-state physics problems.

AH : And we are talking about the late 1970s now ?

HA : Yes, I began the proton transport research, I think, in 1976.

AH : And it went on for how long ?

HA : For five or six years.

AH : And you lived in Nantes ?

HA : No, I remained in Paris while collaborating with the Nantes group.

AH : Were you employed in Nantes ?

HA : No, not at all. At the beginning I was employed at the Ecole Polytechnique as a research assistant, and then I was hired by the CNRS - in 1977.

AH : So, the CNRS paid your salary, you were able to do basically whatever you wanted, and you collaborated with Jean Rouxel and coworkers because you found it interesting ?

HA : Yes. It was a chance to work with an outstanding chemist. French chemists were really very good. The problem, as we just said, was that there was little interest in application.

AH : What did you do next ?

HA : After my PhD thesis, I found it interesting to go to industry.

AH : I imagine that there were many advantages and disadvantages to leaving academia for industry. For instance, where was status greater, what paid better, where were working conditions better ?

HA : First of all, it was rare, even more so than today, for CNRS people, or people within the public system, to go to industry. I cannot give you a clear answer about my motivation - it was not even clear to myself at the time. I did get a higher salary in industry. I also had personal reasons for leaving Paris and going to the Elf company. I went to an Elf research lab in the Southwest of France, in a very nice place in the Pyrénées. I had small children at the time and it was much better for them to grow up in the countryside and in a very nice climate. I was also curious. So the decision involved many elements. And anyway, it was not irreversible. The CNRS allowed me to take a three-year leave after which I could have gone back. With regard to the working conditions : I was of course less free than I had been at the CNRS, but I found it more stimulating because there were a lot of different problems on the horizon, arriving almost every day. We could easily get the necessary equipment at the CNRS and at Elf, so there were no differences there.

AH : The restrictions at Elf had to do with what you were allowed to study ?

HA : Yes.

AH : What did Elf want you to do ?

HA : In principle I was hired to work on solid-state sensors. Because it was not in the direct line of my previous work I proposed that I work on solid-state sensors and ion conduction. We developed a family of sensors named ISFETs (Ion Sensitive Field Effect Transistors). It was a new kind of transistor at the time but now it is very common. You control the electrode using field effects, opening and closing the circuit between the two other electrodes. This is the way the transistor works. My idea - not an original one - was to replace this way of controlling the electrode, the gate, to replace it with a membrane, selective to such and such an ion. If you put the device in a solution containing the ion for which you have designed the system, the membrane will be charged. This charge will change the state of the solid-state transistor. It worked all right for protons. We could use the device to measure pH and afterwards we just had to change the nature of the membrane, choosing a different solid electrolyte, such as calcium fluoride.

AH : Your toolkit remained the same and you still used NMR ?

HA : Not NMR, but yes. You need large samples in order to do NMR. So it was mainly electrochemistry and surface analysis. This was between 1982 and 1985. But as I told you, in industry new projects can arrive almost every day. I had developed some skills in electronics using instrumentation at the École Polytechnique. Elf applied for a patent for a medical analysis system, a small instrument to be sold to private practitioners, as opposed to hospitals. This had nothing to do with solid-state ionics. But the people working on this project needed someone who knew about electronics, and so I got progressively more involved. After one or two years it had become my main project. This worked very well. I was very proud to design an electronic system that required no manual setting. It was set in the factory forever. This was a critical issue, because we thought that doctors could not be expected to deal with electronics - and I am sure that we were right in this. So there was nothing to check or calibrate - the system was self-calibrating. So it worked very well, and after only two or three years Elf built a plant and people were hired. But in 1984 and 1985 there were big changes in chemistry. And there was a great redistribution of all chemical industries. And Elf, that had been an oil company, in this period expanded to become also a chemical company. As a result a lot of the more diversified lines of business lost in importance. Many projects like ours were discontinued. But because we were already quite advanced we found a way to keep going. In fact it was Dupont de Nemours that found that our system was complimentary to some of theirs. The result was that Elf shipped the patent and everything else to Dupont. For a few months I considered following the project to Dupont and to the United States. In the end I decided against. I still wanted to work in solid-state physics and not to work completely in the instrument making business. But for one or two years I continued as a consultant.

2000-05-29 :

HA : For both personal and professional reasons, I decided to stay in Paris, and then Saint-Gobain offered me a position, working in a new research field : polymer adhesion on glass and other materials. It was a new topic for me too. At the time adhesion was not even considered a science. It was before Pierre-Gilles de Gennes's Nobel Prize in polymer adhesion [1991]. It was rather considered an art. Even though I had no background in the field I was interested. What interested me in the Saint-Gobain proposal was that real breakthroughs were to be expected in the science of adhesion when two materials are brought into contact. In fact this was my first real industrial experience. Of course CNRS had not been an industrial experience at all, and even at Elf I was always in the research lab. As I explained, my work at Elf had nothing to do with the industrial activities. I never visited factories. At Saint-Gobain I had to do this, at least in the beginning.

AH : Did you not say that your development of the medical analysis system resulted in the setting up of a plant ?

HA : Yes. I did participate in the design of the plan, in order to make it efficient. But I had no role in the plant itself after construction. It was also a small plant for high-tech activity.

AH : You had nothing to do with the fabrication side of it, situated in the plant – merely the R&D before the plant became functional ?

HA : Yes, exactly. Saint-Gobain of course has many plants all over France and Europe, and even the United States. But at that time, the company was still franco-français [French through and through] in its general spirit and culture, despite the many factories in other countries. There were only French directors and the system was based on the French system of education. There is a hierarchy from the École Polytechnique through the École des Mines and the École Centrale to lesser schools, and you carry the status of your school within you for the rest of your life. I remember that I strongly felt the weight of tradition when I first joined the company. It is true that winds of change were already blowing then, but they were barely noticeable and needed a couple of years before really expressing themselves. But eventually the company changed its culture, and now the company considers itself an international one. I think a deep change has taken place during my 15 years with the company.

So, anyway, this was the first time I gained experience of the industrial aspect of research. My first task was to examine and synthesize different kinds of adhesion in Saint-Gobain's products and processes. I decided to simultaneously pursue fundamental reflection and a practical approach, helping the factories improve their processes. This was a very instructive experience. I learnt many things although I am not sure that I helped the factories all that much. I certainly learnt for myself that I preferred to stay within R&D and not to progress into production. On the fundamental side, I developed a network of contacts in public labs in France and the US. This became useful later on. After three years in the field, and having created a small research lab, I decided to gain some distance from the practical aspect of my work. It was also obvious to me that fundamental research was required first. Progressively the idea came to me to propose the creation a special laboratory dedicated to the basic aspects of polymer adhesion - and of course also to related issues such as the surface science of glass. But I knew that Saint-Gobain was not ready to have a laboratory for basic science by itself, so my idea was to set up a lab jointly with the CNRS. This was in 1988. From the administrative point of view this was feasible : a number of such joint ventures already existed, an example of which is Rhône-Poulenc. Of course I had to convince both Saint-Gobain and the CNRS of the utility of the project which was not straightforward. Although I managed to convince Saint-Gobain in a manner of hours, CNRS needed more prompting.

AH : Would you explain the nature of Saint-Gobain's research before your proposed laboratory ?

HA : It was a quite common kind of R&D geared towards problem solving. Helping the development of new products and solving problems within production.

AH : So the research agenda was driven by questions arising out of production ?

HA : Yes, and my idea was to get a more fundamental understanding of the questions which would enable us to help with such questions in a much better way.

Figure 1. Saint-Gobain Recherche, Paris

At Saint-Gobain I had to sell the idea primarily to the Vice-President of R&D. He took the decision just before retiring. The CNRS process was more complex. It has a democratic organization where decisions are taken by committees. The members consist of both elected researchers and individuals named by the Ministry of Research. They are divided up into different scientific sections. So here I had to convince a diverse group of people, and not just one person, as at Saint-Gobain. As I mentioned, I had developed a network of relationships in the fields of adhesion and surface science and now this turned out to be useful. I knew that many people approved of my research agenda. My project was accepted without much fanfare, but it still took a while because of the administrational hoops that a proposal has to jump through within the CNRS. They meet only twice a year, and every decision has to be validated by the CNRS directors and so on. It took maybe 12 months. The laboratory started on January 1, 1990. But there was only a building and neither instruments nor people.

Figure 2. Joint lab : Saint-Gobain Recherche & CNRS

The three yellow arrows point to the units of the joint lab within the Saint-Gobain Recherche building.

In the meantime I conferred with scientists in many other labs trying to recruit people. Of course the CNRS could not order people to go, so I had to entice scientists away. I estimated that I needed three scientists from the CNRS in addition to three scientists from Saint-Gobain. Two of the latter had already worked with me, and they followed me to the new project. A further researcher came from somewhere else – it was a young Chinese woman. We also had two or three technicians and some PhD students. Altogether, it took a year or so to gather everyone together. We also had to buy instruments and the process of getting the laboratory shipshape lasted altogether something like 2 years. We began to actually do some research in late 1990. And from then on the activities progressed rapidly. In two to three years we reached a plateau of 20 people, a level that had been stipulated by the CNRS. A third of the people had come from the CNRS, a third from Saint-Gobain, with PhD students constituting the last third.

AH : Where did they come from ?

HA : The latter were doing industrial PhDs (Contrat à Durée Déterminée) with Saint-Gobain, and their salary came jointly from the French Ministry of Research and from Saint-Gobain. Of the entire staff, about half each came from chemistry and physics. It was crucial that we develop knowledge and expertise in both these fields. Later we also developed an interest in mechanical problems.

Figure 3. The SPM from Park Scientif Instrument

AH : What was the instrumentation ?

HA : There was a conjunction of the beginning of our lab with the very early days of scanning probe microscopy. This new kind of instrumentation offered a very exciting opportunity. There was a risk in this. We purchased the first Atomic Force Microscope (AFM) ever in France. We bought it from Park Scientific Instruments. Later we built the first AFM for UHV purposes. There were many people then who thought the instrument had no future, so it was a risk to invest time and money in it.

AH : Why did people think it had no future ?

HA : The objection was that it was not clear that atomic resolution could actually be achieved with the AFM. It was not until 1993 that Binnig showed true atomic resolution.

AH : Well, yes, but before he had claimed to achieve atomic resolution. In 1993 he only claimed that so far he had been mistaken and only in 1993 did he achieve true resolution. Is that not right ?

HA : Yes. But in 1993 the community was convinced. The reason I did not hesitate was that atomic resolution was not actually the big issue for our purposes. Even a resolution of 1 nanometer amounted to a great deal. Much could be done with such a resolution in the field of adhesion, and also in fracture mechanics and surface chemistry.

AH : I have the impression that since 1995 or so many people argue that atomic resolution is not really that important, and that in the early 1990s it was still considered the holy grail. So you were unusual in that you had this attitude so early ?

HA : You are right that atomic resolution had a special ring to it in those days.

AH : Did you emphasize the issue of atomic resolution in your application to the CNRS ?

HA : I am not sure. Even today, nobody has achieved atomic resolution in glass. So it would have been a hard sell, also then. The same goes for polymers. And those two were our substances under investigation.
There is a difference between STM and AFM. They obey two different logics. The STM has remained a tool of basic research, in surface science. The AFM, even early on (and this would be interesting to discuss with Calvin Quate or Gerd Binnig), there was a hope that it could be useful, for example in other fields of science, such as mine, or in technology, such as process control, microelectronics, semiconductors, and so on. Generally speaking, in early phases there are always many people who think that a novelty will never become common. We have to remember that in 1987 or 1988 solid probe microscopes were still big and unwieldy instruments. Of course miniaturization had set in by 1990, but it was a novelty. Only very few people were convinced that the AFM would become so common. Calvin Quate is one of the few. The STM has revolutionized basic research on metals and semiconductors. There was a reaction against it, because surface science was done using diffraction techniques working in reciprocal space. Surface scientists were formed in this mode of research. They resisted the change, feeling that newcomers would enter their field without the kind of abstraction that had hitherto been key to access to the field. Working in ordinary space was too easy ! Of course it has not actually become easy because the instrument has brought its own problems, and there are still people working with diffraction and in reciprocal space. The two complement each other.

AH : So this is the background against which your decision has to be seen. You went out on a limb.

HA : Yes. The beginning of my lab coincided with the first commercial scanning probe microscopes (SPMs). We had to grasp the opportunity.

AH : How did you know about the AFM ? Was it a very visible instrument at the time ?

HA : No. I knew about it from publications, but in order to actually see an instrument, I had to travel to California - although I guess I could have seen one at IBM Zurich. There was an STM at Marseille, because two physicists there (Salvan and Humbert) had worked at IBM Zurich, and they had brought one back with them. But they had no experience with the AFM. So I went to the US and visited the very few labs with AFM, both academic labs and the start-up companies of PSI [Park Scientific Instruments] and DI [Digital Instruments]. At Stanford University I met Calvin Quate and at UC Santa Barbara I met Paul Hansma.

AH : Was there a relationship between Paul Hansma and DI ?

HA : I don't remember. But at any rate it was not as close as the one between Quate and Park. I think Park was a former student of Quate's.

AH : So you purchased an AFM from Park. What about the other kinds of instrumentation you purchased for your lab ?

HA : Yes, we had to get other instruments, partly because it took a long time for the AFM to arrive. I had to go to the US to compare the DI and the Park instruments, and I discussed it with the physicists and chemists in our lab before ordering, and then we had to wait for the delivery – maybe 4 months or so. We got a 40% discount, because we were the first French customers, and they hoped that we would open the French market for them. I had very good discussions with Quate, and I think he trusted me to be a good advertisement for him in France. I think we paid 400,000 French Francs, so that the catalogue price was in the order of 800,000 French Francs [approximately US$100,000].

We bought also an infra-red spectrometer, in order to study molecular grafting on oxides. This we used as a complement to the AFM. And as I said in a previous part of the interview, our approach was to combine the traditional surface science (very clean surfaces) with “true surfaces” interacting with the environment. The infra-red spectrometer, XPS (X-ray Photoelectron Spectroscopy), and LEED (Low-Energy Electron Diffraction) were good tools for the traditional surface science approach working in UHV Ultra-High Vacuum). And also HR-EELS (High-Resolution Electron Energy Loss Spectroscopy). Our choice was risky, but it turned out to be correct. Our decision to build bridges between the two approaches was taken in 1992 or 1993. Quite early on in our project we built a surface force apparatus (SFA). It is not at all an AFM – there is no concept of high resolution, but it is similar in that you can get a direct measurement of the force interacting between two objects only a few Ångstroms apart. The idea is to make the measurement quantitative in order to study whether the interaction is due to van der Waals or electrostatic forces. In fact this project took six years – not for technical reasons but simply because we had to get the right people.

AH : Each instrument had its strengths and weaknesses in terms of resolution and the scale of the surface analyzed. And each instrument required special skills. The AFM, for example, requires quite some expertise to disentangle signal from instrumental artifacts, right ?

HA : Yes, artefacts were a real concern at the beginning, when we all had very limited experience. We had to pay much attention in order to ascertain the results.

AH : Can you explain how one separates signal from artefact ?

HA : There are different kinds of artefact. One that now seems quite natural but was hard to understand then is the tip effect. If the surface under examination has sharper topographic features than the tip, then the tip will be imaged rather than the surface. We had trouble with this kind of artefact. In fact, when studying tin oxide deposits on some substrate we got very nice images that we at first interpreted as small crystals having the similar orientation. We were very excited to find a growth mechanism of specific orientations on isotropic surfaces such as glass. I decided to present this result at a small meeting in Davos, Switzerland. The topic there was in fact “The AFM for Technological Applications”. Famous scientists attended, including Calvin Quate, Jim Gimzewski, and Heinrich Rohrer. There were only some 10 people there, because this was very early, maybe 1991. The night before my presentation, I began to wonder that the result was really too beautiful to be true. I telephoned my lab and asked people there to turn the sample by some angle and do the experiment again. That way, the features should have changed if they belonged to the surface. But they did not, and so we knew that the features belonged to the tip. So I did not present that particular slide in my talk.

AH : So rotating the sample by some degree is one way of identifying artefacts.

HA : Yes, that will eliminate this kind of artefact, the tip effect. There are also adhesion artefacts, some of which have been solved in the meantime thanks to new recording techniques such as the tapping mode.

AH : Digital Instruments has a patent for the tapping mode, right ?

HA : Yes.

AH : So the Park instrument that you bought did not have the tapping mode ?

HA : No it did not. The tapping mode did not become available until 1993 or so. Later on, Park Scientific Instruments did do something similar, but they may not call it tapping mode. The DI patent covers the name. And in the straightforward contact mode many artefacts were possible ; for example when looking at soft materials and polymers surface scratches easily occur. If you do that you image the substrate only. One way to identify this effect is to scan again with a smaller tip-surface interaction. In some cases you will find miniature small squares where the surface had been damaged in the course of the first scan. Some artefacts are very common, others are quite specific and harder to identify.

AH : In what you have explained, the identification of artefacts is internal to the instrument itself. It is not that you can go and compare the results of an AFM scan with those from a different instrument ?

HA : You can change the tip, and you should identify artefacts unless you are very unlucky to get the same tip. Everybody understood that the AFM has great potential not just as an imaging instrument but also to measure adhesion, hardness and so on.

AH : Using force-distance curves ?

HA : Yes, force-distance curves. This turned out to be very useful for us. For instance in order to understand the electrostatic interaction between oxide and a silicon nitride tip under water. This was original work. For example, in polymer adhesion we checked if it stayed on the substrate and what scratching would do. Of course such ideas were floating around at the time.

AH : Were you important to the subsequent spread of the AFM in France ?

HA : Yes, people came to our lab. Another lab, at the Institut Curie, that got an AFM at almost the same time. For a while we were a small community but then gradually we grew larger and larger. Yes, we were the pioneers. It was exciting.

2001-02-20 :

HA : I went with one of my sons who was 11 years old at the time to see Park Scientific Instruments. There were no more than 10 people working there, in fact I think it was more like three. It was very small and familial. We discussed and had tea. I enjoyed discussing with these people. It was nothing like an established company.

AH : What did it look like ? Did they work out of a garage ?

HA : Something like between a home and a garage. It was a small house. Even Digital Instruments started out like this. Already in those days DI, and especially Virgil Elings, was much more commercially aggressive, but they were very small too at the time.

AH : Did you stay in touch with some of these guys ?

HA : I stayed in touch with Calvin Quate for five or six years, until 1996. After that I lost the contact but he will probably remember me because we had many discussions. It was curious to see his impact upon materials science. In fact it was very difficult for him to get the first paper on the AFM accepted in Physical Review Letters. Some of it was considered just a pure mechanical profilometer. It had good resolution but it was not really anything new. His project now is very interesting from what I can tell reading his articles in the scientific journals. And he really is a very nice person. Maybe the last time I saw him is when I invited him to give a talk at Saint-Gobain Recherche.

AH : So you stayed in touch with him in the early 1990s, while you were developing your own AFM. I guess the use of the AFM changed the project from what you had originally envisaged ? Did you continue using all the other tools or did you focus exclusively on the AFM ?

HA : We used the other tools.

AH : What did you buy for your laboratory ?

HA : Infrared spectrometer, XPS, HR-EELS (High Resolution Electron Energy Loss Spectrometer), LEED. Quite quickly we had three AFMs. I wanted to develop a PSTM working in the infrared but unfortunately that particular project died because the physicist we had working on it left.

AH : What journals show the history of these instruments best ?

HA : In the beginning it was mainly in the general physics journals such as Applied Physics, Applied Physics Letters, Physical Review Letters, Surface Science. Now there are specialized journals. A journal like Journal of Scientific Instruments is not so important in this respect. Langmuir is also important for soft matter.

AH : Do any of these journals have review articles ?

HA : I am almost sure that all of them do.

AH : We were talking about the various instruments you had in your lab. How did you apply them to your research project ?

HA : The idea was to have two parallel approaches. We were mainly interested in adhesion, molecular grafting and so on. One approach is the classical view of surface science, the ideal surface approach. The other is the REAL surface approach, taking the environment as a part of the system.

AH : Not working in Ultra-High Vacuum (UHV) ?

HA : Yes. But we were trying to make the two approaches meet.

AH : So when you started working with the AFM in UHV, the point was to simplify the experiment ?

HA : Yes.

Figure 4. UHV Chamber et AFM in UHV Chamber

If a probe were to be introduced directly into the UHV chamber, it would take days of pumping to achieve UHV. Instead, it is first introduced into an antechamber, whereupon a vacuum is produced there. Only then can walls be opened without reducing the UHV too much. By pushing the rods labelled 1 and 2, the sample is transported in successive stages into the central chamber. Several instruments are attached to the chamber, including an XPS. On the right, an AFM can be discerned in the UHV chamber.

AH : How did the various instruments complement each other ?

HA : The spectrometers provided structural information. They give a chemical signature. One point of interest was silver on magnesium oxide. In order to have a simple model of glass we chose to study this problem within pure single crystal. We had the probe in situ in the same UHV chamber where we had the instruments to add the deposition techniques. In the case of silver it was just thermal evaporation. We wanted in situ real-time studies of the atoms arriving upon the substrate, the oxide surface. There were two models in this problem. One was that the atoms remain isolated or form small islands, so that the growth process is two-dimensional, so that you first get a perfect monolayer before a second layer is started upon. The other is that growth is three-dimensional with occasional collapses into flatness. To study this it is of course useful both to look directly and to use diffraction techniques. But in order to understand the process you need to grasp the interaction between the silver and the oxide. And only spectroscopic techniques will help here. We always tried to look at a problem from two differing points of view – in this case geometrical and chemical.

AH : You make it sound easy. You just use one tool and you get the topography, and then you use another and you get the chemical composition.

HA : Well of course it is not at all easy. It was very difficult because for instance, the STM works very well when you have a smooth surface but when you have corrugation it becomes much more difficult, because this corrugation interferes with the instrument. In spectroscopy you integrate over the size of the beam which is much larger than the surface scanned by the AFM. So you have to do many different experiments to see what effect the temperature has and so on. You also have to model the interaction. This was a little known problem. What is the mechanism of very small silver clusters on magnesium oxide with other silver clusters in the neighborhood ? It was a new problem. So it took time to understand the system.

AH : What is the measure of success ? It was partly CNRS, so you were under pressure to publish ?

HA : Yes.

AH : And since it was partly Saint-Gobain you had to get patents ?

HA : We had to do both. It was an interesting exercise in communication. In my position as head of the lab, I could not use the same words, the same way of presenting things when addressing different audiences. From time to time it was necessary to gather the scientific and the industrial people together under one roof.

AH : And what language did you speak then ?

HA : Fortunately everyone was happy with this lab, so it was not quite so difficult. The conditions were good. Nonetheless your question is quite correct. It was interesting.

AH : How did you convince Saint-Gobain that this would have a pay-off ? And how did you negotiate long- and short-term goals ?

HA : The short term was a problem. It was not straightforward to plan a new product for the company. The pay-off was very diffuse and difficult to identify. One way of motivating the directors was the argument that we trained very good PhD researchers for Saint-Gobain. And this was not expensive for Saint-Gobain, because they shared all the expenses with CNRS. Up until now this has not been a problem.

AH : Stanley Whittingham told me that in the last 15 years or so there has been a tremendous shift in company planning towards the short term in industry. Partly this was due to the MBA education and the fanning out of this new generation of business administrators into all nooks and crannies of industry. As a result the long-term disappeared, because everything had to fit into the financial year so that you have something to show to your shareholders.

HA : It is true that this has taken hold in industry. We had the good fortune that it was not very developed in Saint-Gobain. But also, the time required for the development of new glass materials just is acknowledged to be greater than that in electronics or informatics. When we start new projects, we are simply not able to show a product six months later. So we are less exposed than people in other fields, but the general development that you alluded to certainly has taken place. Maybe our situation will also change in the future. We may be excessive.

AH : Has the accountancy changed for you ? Did you have to write annual reports ? And has it changed over the last ten years ?

HA : In general ?

AH : Well, for the CNRS I can sort of imagine it. In academia you would specify the number of publications that you have produced and that is the measure. End of story. And that is very simple accountancy. But if you account to a company, keeping in mind the increasing influence of MBAs : did you have to account for your expenses in ever greater detail ?

HA : I do not think there has been such a change in the last decade.

AH : And do you write annual reports ?

HA : Bi-annual. But I am not in this lab anymore ; I left two years ago.

AH : Okay, so during the 1990s up until two years ago you wrote biannual reports to the company and in that period the structure of the reports did not change.

HA : That is correct.

AH : Did you have to specify just how much money you spent ?

HA : Yes, but also there, no change took place. And I always reported to the same person within Saint-Gobain. He was basically content with what we did, so it was never critical. It is true, it might have changed with a different person in charge.

AH : So, how did the instrumentation change throughout the 1990s ? The AFM became commercially available to an ever greater extent, you were able to buy many more things off the shelf. Is that true also of all the other instruments ?

HA : Yes, there are different aspects to your question. We used to build many instruments ourselves, and this was of great use for training. And this has changed. A reason the French PhD has been shortened is that equipment is being bought and not made in-house. That is a general trend. Science is changing as a result, because using a commercial instrument is not the same. When you develop an instrument yourself you know exactly how to get the result. In the specific case of AFM/STM : probably the AFM has been developed much more than the STM. In the STM the major breakthrough was with the driver and that was quite early. I think it was possible to purchase an STM driver already by 1992. Variable temperature was a little more difficult, but it was certainly available by 1994. Different ways of scanning and acquiring information were developed. Otherwise the evolution was purely technical : cheaper, and more diverse (such as an STM expressly for electrochemical research). By contrast the AFM has developed rapidly. Tapping mode and other modes where you measure not only the distance but also hardness, conductivity, adhesion, chemistry. It has become possible to map all these parameters. This explains why more and more people use the AFM.

AH : It has also become cheaper, right ?

HA : Yes.

AH : It has certainly become more user-friendly, adaptable to different circumstances.

HA : Yes. For the STM : there have very beautiful studies made of the coupling between tunneling and modulation. You might modulate the tunneling current with light for instance. You can even leverage the spin of the tunneling electrons. So you can do beautiful physics. But this contributes little to the democratization of the technique.

AH : I have the sense that Calvin Quate, by contrast, is working hard to increase throughput.

HA : Yes, that is right. There can be two reasons for doing that. To make the investigated part of the surface larger – of use in the semiconductor industry. And to shorten the time required for a scan. He is trying to use the system technologically.

AH : Okay. Two years ago you left your lab. Your own lab. Why ?

HA : I wanted to try something new and I was lucky to find someone who was well capable of taking over and for whom I have a lot of respect. He is from a different background. So now it is a different group. I became the Scientific Director of Saint-Gobain Recherche. There are two parts to the job ; one is to be the scientific manager, the other is to establish contacts in the outside world, and to promote innovations within the company, for instance with the marketing people.

AH : You were promoted ?

HA : Yes.

AH : And you have become slightly removed from lab work ?

HA : Yes, completely, I am now involved in organizational work.

AH : In fact, our project resembles your job in the sense that we stand back and look at the scientific research and try to gain a perspective ?

HA : Yes, you could say that.

Fin de l'enregistrement

Pour citer l'entretien :

« Entretien avec Hervé Arribart », par Arne Hessenbruch, 19 février, 29 mai et 20 février 2001, Sciences : histoire orale, /spip.php ?article47.

Pour citer l'entretien :

« Entretien avec Hervé Arribart », par Arne Hessenbruch, 19 février, 29 mai et 20 février 2001, Sciences : histoire orale, https://sho.spip.espci.fr/spip.php?article47.

Lieu : dans le salon (les 19 février et 29 mai 2001) et dans la petite salle de réunion (le 20 février 2001) du Dibner Institute, Etats-Unis.

Support : enregistrement sur cassette.

Transcription : Arne Hessenbruch.

Édition en ligne : Sophie Jourdin, Sacha Loeve.

GAUTHIER Sébastien, 2006-11-16

2009-12-15T15:58:16Z

Sébastien Gauthier, né en 1956, est physicien, directeur de recherche CNRS. Il soutient sa thèse en 1981 à l'Université de Paris Diderot. Elle porte sur une étude quantitative de la spectroscopie tunnel. Il travaille ensuite au Groupe de physique des solides de Paris Jussieu (Universités Paris 6 et 7 - CNRS). Il contribue à y développer la microscopie à effet tunnel pour l'étude des surfaces cristallines. Puis il intégre l'équipe « STM, AFM, NFOM, nanomanipulation, surface » du Groupe Nanosciences (GNS), coordonné par Christian Joachim au Centre d'élaboration des matériaux et d'études structurales (CEMES). Ses recherches au CEMES concernent l'instrumentation associée à la microscopie en champ proche, les nanosciences et l'électronique moléculaire.


Autorisation de diffusion

SACHA LOEVE (SL) : Pourriez-vous nous dire où vous avez été formé au STM ?

SÉBASTIEN GAUTHIER (SG) : Où j'ai été formé ? Et bien... nulle part ! Quand on a démarré, on partait de pas grand-chose. Je suis allé à Zürich, là où a été construit le premier STM. J'ai vu Rohrer, qui m'a reçu. Il m'a expliqué un certain nombre de trucs. Il m'a donné une photo de son appareil, et avec ça, je me suis débrouillé ! J'avais des questions à lui poser, et il m'a expliqué. Il m'a montré un certain nombre de choses, voilà... et puis j'en ai fabriqué un.

XAVIER GUCHET (XG) : Et le STM que vous aviez fabriqué, il était différent de celui de Rorher ?

SG : Oui, un peu différent. Je suis quand même parti de ce qu'il m'avait montré, après, ça a évolué de manière assez différente.

XG : Et il y avait beaucoup de physiciens qui, comme vous, s'intéressaient déjà à cet époque à cet instrument, qui en fabriquaient ou essayaient d'en fabriquer ?

SG : Oui, enfin, en France, il y avait quatre ou cinq groupes qui s'y sont mis à la même époque.

XG : Il y avait beaucoup d'échanges entre les groupes ?

SG : Au début, oui. On était tous dans le même bateau.

XG : Peut-on dire qu'à cette époque, une petite communauté STM s'était constituée ?

SG : Oui, je pense. Il y avait cinq labos qui avaient démarré simultanément, avec pas mal d'échanges.

XG : Et aujourd'hui ?

SG : Aujourd'hui, le problème, c'est que le STM sert à tellement de choses différentes que ce sont des communautés différentes. Même si il y a des recouvrements, les thématiques sont très variées. Et l'instrument en lui-même ne suffit pas à souder les gens... C'est vrai que je connais personnellement beaucoup de gens qui font du STM sur des sujets très différents, c'est sûr ; mais je n'ai pas forcément d'interactions avec eux sur le plan scientifique, même si j'en ai sur le plan technique. Sur le plan technique oui, un peu, mais pas sur le plan scientifique.

XG : D'après ce qu'on avait cru comprendre, le STM, c'est quand même un instrument manipulé par des physiciens, pensé par des physiciens, mais qui commence à se diffuser dans des communautés qui ne sont pas celles des physiciens, mais des chimistes, des biologistes, d'autres communautés qui commencent à l'utiliser. Est-ce que c'est quelque chose que vous constatez ?

SG : Oui, mais c'est le cas depuis le début. En particulier, il y a eu les biologistes, beaucoup de biologistes... Disons que le STM a suscité pas mal d'espoir pour certaines recherches en biologie ; et donc, il y a des labos de biologie qui se sont équipés dès le début... et il faut bien dire que ça n'a pas été un franc succès. Parce que cet instrument, il n'est pas comme un microscope optique : je veux dire que faire des images avec, ce n'est pas tout à fait simple ; interpréter des images, ça n'est pas simple non plus, alors bon... je ne veux pas dire que le STM, c'est l'exclusivité des physiciens, mais que ce n'est pas un appareil que l'on peut utiliser en routine de façon habituelle. Enfin après, tout dépend ce que l'on veut faire avec, mais souvent, il y a beaucoup d'artefacts. Maintenant, les gens sont spécialisés. Il y a des gens qui travaillent pour les biologistes, mais en général ce sont des physiciens qui sont allés vers la biologie quand les biologistes sont allés vers la physique. Ce sont des physiciens, mais qui ont une espèce de double compétence. Ce ne sont pas des appareils que l'on peut utiliser comme ça. Ce n'est pas routinisé.

XG : Et ces biologistes qui se sont équipés : ils ont acheté des STMs, ou ils ont fait venir des physiciens dans leur labos ?

SG : Il y eu les deux. Certains ont seulement acheté des appareils ; et il y a des physiciens qui sont venus dans la biologie avec l'instrument.

SL : Ce qui implique, pour les recherches en biologie, qu'ils n'utilisent pas le STM en ultravide ?

SG : Oui, en pratique pour les biologistes, la plupart du temps c'est même en milieu liquide qu'ils font tourner le STM.

SL : Alors ces labos de bio qui se sont équipés en STM, vous disiez que ce n'était pas un franc succès. Bref, comment vous voyez ces travaux ?

SG : Alors en effet, il y a des labos qui ont acheté un STM. Ils ont constaté qu'ils n'y arrivaient pas et ils ont laissé tomber. Il y a des labos qui se sont dit « il faut que j'y arrive » : ils se sont mis à fond là-dessus et il y a des cas où ça marche, justement, en milieu liquide. Il y a des physiciens qui sont allés vers la biologie parce que ça les intéressait. Il y a eu un peu tous les cas de figure. Mais ça demande une compétence... oui, une compétence de physicien que les biologistes peuvent acquérir, bien sûr, mais néanmoins, le biologiste, il faut bien dire qu'il n'est plus tout à fait exclusivement biologiste quand il commence à travailler avec cet outil. Inversement, il y a eu des physiciens qui ont voulu s'intéresser à des problèmes de biologie et qui sont tombés complètement à côté. Ils qui ont fait des choses qui, finalement, n'avaient aucun intérêt du point de vue de la biologie. Il obtenaient peut-être des belles images au niveau de la physique sur des objets biologiques, mais bon, c'était limité.

XG : Vous avez un exemple de ce cas de figure ?

SG : Je n'ai pas tellement d'exemple très précis là-dessus mais je sais qu'il y a eu pas mal de scepticisme chez les biologistes quand à ce qu'apportaient ces travaux. Ceci dit, ce n'est pas dû au STM, c'est un peu général... il faut dire que la façon dont les physiciens abordent les problèmes des biologistes se fait par une approche de physicien et non pas de biologiste... et il y a des biologistes qui trouvent que cela n'a pas d'intérêt.

XG : Est-ce que vous continuez à essayer de perfectionner le STM ?

SG : Oui. Tout le temps oui. C'est quelque chose de permanent. Perfectionner, modifier, adapter l'instrument à de nouvelles choses.

SL : Quelle est la proportion, au CEMES, entre les instruments qui sont achetés tout faits, ceux qui sont construits « maison », et ceux qui sont moitié commercial, moitié construits ?

SG : Oh, la tendance est clairement à acheter, maintenant.

SL : Et ça a changé beaucoup de choses ?

SG : Oui. Enfin pour ce qui concerne la microscopie en champ proche, oui, ça a été un changement. Mais ceci dit, il y a encore des gens qui fabriquent, ce n'est pas exclu. Mais il y a eu pas mal de changements à ce niveau là, oui.

SL : Pour quelle raison fabrique-t-on et pour quelle raison achète-t-on un STM ?

SG : Et bien au début, on fabriquait parce il n'existait pas d'appareil standard. On ne pouvait pas acheter un STM. Maintenant, on achète parce que finalement, développer coûte aussi cher que d'acheter parce que cela prend beaucoup de temps pour des résultats qui sont parfois meilleurs d'ailleurs... enfin cela dépend... c'est pour cela qu'on trouve des labos où on en fabrique encore et d'autres où on achète. Pour nous, en ce qui concerne les choses récentes, on a plutôt acheté.

SL : Qu'est-ce qui fait que l'on peut avoir un meilleur résultat quand on a un microscope qui est construit ?

SG : Pour un microscope à effet tunnel, ce qui est important c'est la stabilité. La température à laquelle on travaille est aussi très importante. Après, il y a beaucoup de choses autour. C'est rare que l'on fasse que du STM. Il y a plein d'autres techniques, un ensemble de choses disposées autour (figure 1) et qui varie d'une expérience à l'autre. Par exemple, il faut transférer l'échantillon. C'est toujours une opération un peu compliquée, plus ou moins facile ou difficile. Enfin, il y a toutes sortes de commodités annexes qui sont importantes dans l'utilisation quotidienne. Il y a des appareils beaucoup plus lourds à utiliser que d'autres. Cet aspect est important aussi.

Figure 1. Le STM et ses dispositifs périphériques.

XG : Vous voulez dire que le STM est devenu un instrument parmi d'autres ?

SG : Non pas tout à fait. Pour nous, c'est l'instrument central, en général, dans les manips' que l'on fait. Ce qu'il va y avoir autour, au niveau instrumentation, dépend un peu du type de physique qu'on fait avec le STM. Par exemple, le problème avec les molécules, c'est que le dépôt est important. Il faut donc pouvoir déposer les molécules sur les surfaces comme on aimerait qu'elles le fassent, ce qui n'est pas toujours très simple. Il faut donc aménager des dispositifs pour le faire.

SL : On peut vouloir faire des choses très différentes avec le STM. On comprend bien que les possibilités sont très larges. Mais encore faut-il que les instruments le permettent. Les instruments commerciaux ont-ils toujours toute cette variété de fonctionnalités ?

SG : Si, et ils l'ont mêmes plutôt davantage que les instruments construits, mais il y a des cas où, si on développe un instrument pour une utilisation spécifique, il sera peut-être plus simple et peut-être plus performant pour cette application-là que l'instrument commercial, qui lui peut tout faire, mais... un peu moins bien. C'est souvent le cas de figure. Et puis aussi, l'intérêt d'un appareil qu'on a fait soi-même, c'est que c'est quand même plus facile à réparer qu'un appareil commercial. Et les budgets de maintenance il ne sont pas négligeables. C'est aussi à prendre en compte.

XG : Oui d'accord, évidement, un appareil qui a été fabriqué par vous il...

SG : il est plus réparable mais pas forcément plus simple... Enfin au moins, on ne dépend pas d'un service après-vente !

SL : Une fois qu'on l'a monté on sait comment le démonter...

SG : Oui.

SL : Et vous qui avez construit ce type de microscope, est-ce que vous vous occupiez aussi du soft, de l'électronique ?

SG : Ah oui, c'est pareil pour les softs. Au début, on faisait les softs du STM, maintenant, on les fait beaucoup moins.

SL : Et les logiciels développés par le labo, ESQC et STM Virtuel ?

SG : Le logiciel ESQC c'est un logiciel de calcul d'image, l'autre, de simulation. Mais ce n'est pas le logiciel qui pilote l'appareil. ESQC c'est du calcul d'image, le STM Virtuel c'est un peu différent. Il utilise l' ESQC mais c'est une sorte de superstructure qu'il y a autour.

SL : D'accord. Mais pour le traitement des images, j'imagine qu'il y a eu des standards, des normes à adopter dans la conception de l'électronique, pour stabiliser les images ?

SG : Des standards ? non. Et c'est pour ça qu'il y a tellement de types de microscopes, de microscopes à effet tunnel. Il n'y a pas une proportion très standardisée, non je ne pense pas.

XG : D'accord c'est-à-dire que le STM qui est utilisé ici, ça ne va pas forcément être le même que chez le voisin ?

SG : oui, sauf que celui qu'on utilise maintenant est commercial, donc il y a un standard qui est imposé par l'entreprise qui le fabrique. Sinon, pour les appareils fabriqués il n'y a pas forcément de standard.

XG : Et l'offre commerciale, elle est très importante pour ces outils là, ou alors est-ce qu'il y a très peu de modèles, finalement, à choisir ?

SG : Par exemple, pour ce qui est du STM en ultravide, des fabricants sérieux, il y en a peut-être cinq sur la planète. Entre cinq et dix, mais je dirais plutôt cinq que dix. Chacun propose deux ou trois modèles différents. Vous voyez donc que ce n'est pas gigantesque.

XG : Et la différence des images obtenues, peut-elle être très importante d'un modèle à l'autre ?

SG : Non. Parce que la qualité des images dépend quand même beaucoup du savoir-faire de la personne qui manipule ce truc là ; ça dépend des échantillons ; de la préparation de la surface ; ça dépend de tellement de choses qui ne sont pas liées à l'instrument qu'on a beaucoup de mal à isoler la contribution de l'instrument dans le résultat.

XG : Et ça représente un changement par rapport au tout début de cette aventure ?

SG : Au début, il y avait effectivement des choses pas très fiables... mais bon il y a encore des bons et des mauvais instruments, c'est clair ; mais ça dépend de ce qu'on veut voir. Pour un certain type d'expérience, c'est clair qu'il faut avoir l'instrument adapté. A partir de ce moment là, les différences sont davantage liées au savoir-faire des gens qu'il y a autour que des instruments, très souvent. Bon, il y a aussi des instruments qui marchent bien mais qui sont beaucoup plus lourds à utiliser. Ce qui fait que les gens seront un peu moins productifs avec ce type-là d'instrument. Mais sinon, en termes de résultat, c'est difficile de montrer ce qui marche le mieux. C'est difficile à montrer. Il y a des groupes qui ont une grosse tradition de STM et d'autres qui l'ont moins, et c'est à ce niveau là qu'on voit la différence, c'est pas tellement au niveau de l'instrument lui-même.

XG : Vous, avec le recul, vous préférez travailler avec un instrument que vous avez acheté, ou que vous avez fabriqué, ou alors cela vous est indifférent ?

SG : Dans l'absolu, je préférerais travailler avec un instrument que j'ai fabriqué. Après, en pratique, si l'instrument marche bien, alors je n'ai pas de position de principe... Peut-être avec un exemple... tiens, le problème avec l'instrument que j'ai maintenant c'est que le soft il ne fait pas tout ce que je voudrais qu'il fasse. Et aller mettre le nez dans le soft actuellement c'est impossible parce qu'on n'a pas les sources. Alors là, on est complètement dépendant des gens qui vendent le logiciel. Et donc, qu'est-ce qu'on peut faire ? Soit on refait un logiciel complet, soit on est coincé. Mais si on a pas les sources c'est vraiment... Alors que sur un instrument fabriqué, moyennant le temps... si on suppose qu'on a le temps de développer le logiciel, on a toujours la possibilité de le faire, alors que là, par principe, on ne peut pas le faire.

SL : Vous ne pouvez pas faire appel au constructeur ?

SG : Pour les constructeurs, si il y a vingt groupes différents qui demandent la même chose, ils le feront. Si il y a un groupe qui demande quelque chose, il ne le feront pas. C'est la logique commerciale. Ils ne vont pas faire quelque chose comme ça à l'échelle d'un groupe. Ou alors, ils vont faire payer le service tellement cher que ce ne sera pas intéressant.

XG : Et quand vous dites « je ne peux pas faire ce que je veux avec le soft », cela va évidemment influer, j'imagine, sur les rapports que vous avez avec les chimistes qui synthétisent les molécules que vous manipulez et les autres physiciens qui aident à la conception ?

SG : Oh... un petit peu... certainement...un petit peu oui...

XG : Vous pouvez être plus précis ?

SG : Oui, par exemple, cette histoire de molécules qu'on peut déplacer avec la pointe du STM, il se trouve que c'est pas facile à faire. C'est compliqué quoi, on ne peut pas tout faire. Donc, si on a une idée de projet où il faut absolument manipuler une molécule de manière sophistiquée, on va avoir tendance à dire « non on peut pas le faire » ; l'idée, on va l'écarter tout de suite, on va se censurer là-dessus. On va plutôt essayer de faire des choses qu'on sait faire. Et donc l'instrument, ce qu'on sait faire avec lui, ça conditionne les choses. Ceci dit, comme il y a beaucoup de choses à faire, ce n'est pas une limitation majeure pour l'instant. Le jour où on aura une idée de projet où on considérera qu'il faut absolument faire une manip' compliquée, alors soit on trouvera un moyen de la faire, soit on sera effectivement coincé.

XG : Là, il n'y aura pas d'autre solution que de racheter un autre appareil ?

SG : Oui ou, enfin, de refaire un logiciel ou de faire... une astuce. Ou alors, d'aller voir le fabricant pour essayer de le convaincre... et il faut avoir les moyens. C'est sur ces limitations que cela se joue.

XG : Vous connaissez des collègues qui continuent de fabriquer eux-mêmes leurs instruments ?

SG : Oui. J'en connais même un certain nombre. Je connais quelqu'un à Paris, Dimitri Roditchev. Il travaille à l'INSP [Institut des NanoSciences de Paris] à Paris, mon ancien laboratoire. Lui, il continue en partie à construire. Il y a des choses qu'il achète et des choses qu'il fait... c'est un peu l'école russe.

XG : Donc cette logique, celle d'abandonner la fabrication des instruments et de se mettre à acheter, elle n'est pas inexorable, finalement ?

SG : Elle n'est pas inexorable en effet, mais après, tout dépend des moyens qu'on a sur le plan technique. Pour faire du développement, il faut des gens, il faut des mécaniciens et, éventuellement, des électroniciens. Il faut tout ce monde-là, et cela prend du temps. Donc soit on a du temps, soit on a de l'argent, et si on a les deux, alors c'est parfait. Mais nous, ici, on a plutôt de l'argent mais pas beaucoup de bras, et donc ça dicte forcément une logique : celle d'acheter de l'appareil commercial. Si on a avait moins d'argent et plus de bras, peut-être qu'on construirait encore. Et puis les appareils commerciaux ont fait beaucoup de progrès aussi. Ça dépend un peu de tout ça.

XG : Est-ce que vous pensez qu'il est envisageable, si jamais vous bloquez un jour sur des limites liées au soft, d'envoyer les molécules, pour les faire traiter par des instruments fabriqués qui, eux, n'auraient pas cette limitation ?

SG : Bien sûr. Ça on le fait, oui. Parce qu'on est dans des réseaux européens, avec un certain nombre de gens qui font du STM. Et en fait, la répartition du travail se fait souvent sur ces bases-là. On peut très bien faire une molécule ici, faire une partie du travail dessus, et puis l'envoyer pour que ce soit repris par un autre groupe qui lui, peut très bien faire autre chose. C'est assez courant en fait.

SL : Et vous utilisez beaucoup l'AFM, également, au CEMES ?

SG : Globalement l'AFM est beaucoup plus utilisé que le STM, mais pas pour ce qu'on fait nous, parce qu'on travaille dans l'ultravide. Le problème avec l'AFM, c'est que sa résolution n'est pas au niveau du STM. Voir des molécules isolées, comme on le fait nous, c'est quelque chose qui n'est pas du tout routinier, et donc pour l'instant, il se trouve qu'on fait de l'AFM, mais que dans le contexte « molécule unique » c'est encore quelque chose qui n'est pas très... disons qu'à ce moment-là, imager la molécule à l'AFM est une fin en soi, alors que ce n'est plus le cas en STM. En STM, imager la molécule, c'est la première étape. En général, on veut aller beaucoup plus loin ensuite. En AFM, si on arrive à imager une molécule, on est déjà assez content. On essaiera peut-être de passer au-delà mais disons que ce qui, avec le STM, ne nous satisferait pas est suffisant en AFM pour l'instant. La résolution n'est pas du même niveau.

XG : Les chercheurs en matériaux utilisent davantage l'AFM ?

SG : Oh et bien l'AFM, c'est un instrument qui sert à tellement de choses... il sert au gens qui font des polymères, il sert à des biologistes...

XG : Je voulais dire dans le cadre du CEMES...

SG : Au CEMES, oui. L'AFM sert un peu au gens qui font du matériau, pour caractériser en surface la rugosité, la texture et des choses de ce genre. Mais là, c'est utilisé plutôt comme un appareil de routine parmi toute une palette de techniques. Il n'est pas du tout central pour eux comme le STM l'est pour nous.

SL : Et du microscope optique en champ proche, où la pointe est, si je comprend bien, une fibre optique ?

SG : La pointe est une fibre optique qui vient capter les photons près de la surface et qui utilise cela comme information pour faire de l'imagerie.

XG : Et c'est un appareil acheté ?

SG : Non, fabriqué.

XG : C'est vous qui l'avez fabriqué ?

SG : Non, c'est quelqu'un qui s'appelle Renaud Péchou. il a fabriqué ça il y a un petit moment.

SL : Il y a beaucoup de types de microscopes en champ proche aujourd'hui, non ? C'est tellement diversifié, spécifié...

SG : Ah oui, aujourd'hui, c'est tout un catalogue. Selon le type de sonde qu'on utilise, il y a vraiment pas mal de choses différentes.

SL : Elle s'est diffusée relativement vite quand même, la microscopie en champ proche ? Si on la compare par exemple avec la spectroscopie, on a l'impression que ça a pris très vite.

SG : Oui ça a pris assez vite. L'AFM c'est 1986, le STM c'est 1982. Après, je ne sais pas trop à quoi il faut comparer. Mais oui, ça a été vite. Surtout l'AFM, je dirais. L'AFM est beaucoup plus utilisé que le STM maintenant mais surtout en air, et comme appareil plutôt accessoire... il est dans un coin du labo, l'AFM, et puis, on y passe un échantillon de temps en temps.

XG : J'aimerais savoir une chose : être surpris par ce que fait la molécule que vous manipulez, par rapport à ce qui était prévu, ça arrive souvent ?

SG : Cela arrive souvent oui.

XG : Vous avez un exemple en tête ?

SG : Je n'ai pas d'exemple très précis. Je sais qu'il y a certaines molécules, comme celles qu'a fait André Gourdon et qui s'appellent les « landers », qui ont été développées pour une application bien précise, et qui se sont retrouvées servir à une multitude d'autres choses.

SL : Et il y a le cas des roues de la brouette non ? C'était des dimères, et puis on a aussi trouvé des trimères et d'autres fragments ?

SG : Oui, les brouettes, c'est un projet où pour l'instant, le gros problème, c'est déjà de mettre la molécule à peu près intacte sur la surface , ce qui n'est pas évident. Disons que elle n'a pas fait quelque chose de très inattendu, pour l'instant, cette molécule. Bon, c'est un projet ambitieux qui requiert pas mal d'étapes... pour l'instant, disons qu'il n'y a pas eu beaucoup de choses inattendues.

XG : Qu'est-ce qui a motivé, en 1997, votre arrivée au laboratoire. Pourquoi avait-on besoin, à ce moment là, d'un spécialiste du STM ?

SG : Et bien parce qu'au laboratoire, ici, il y a avait les chimistes de synthèse qui étaient déjà là, et il y avait la partie théorique où il y avait du calcul d'image. Mais il n'y avait pas de partie expérimentale STM. Il y avait un trou.

XG : Avant 97, il n'y avait pas de STM du tout au CEMES ?

SG : Non, pas dans la partie qui s'appelle GNS, ou « électronique moléculaire ».

SL : C'est quand Christian Joachim a commencé à vouloir faire de la molécule unique que sont arrivés les STMs ?

SG : Pour la chronologie, je ne sais plus très bien à vrai dire. Oui, disons que c'est à peu près à cette époque-là. Christian [Joachim] et André Gourdon étaient déjà ici. Ils travaillaient déjà avec le labo d'IBM à Zürich par exemple... donc il y avait visiblement un trou ici, parce qu'en effet, pourquoi aller faire à Zürich ce qu'on pouvait faire ici ? Et c'est comme cela que je suis venu. Effectivement, il était déjà question de molécule unique, oui.

XG : Vous êtes combien, vous, les physiciens, à vous occuper des instruments, type STM, AFM ?

SG : Pour la partie électronique on est deux CNRS, un prof et trois thésards.

XG : Et concrètement, les thésards, c'est quoi leur travail ici ? Ils contribuent à améliorer les instruments ?

SG : Non, leur travail, c'est de faire des manips', de faire fonctionner les instruments, éventuellement de les modifier si il y a besoin oui, de les modifier pour quelque chose, d'interpréter les résultats, d'essayer de faire des calculs ; leur travail, c'est tout le spectre : de la clef de douze à l'ordinateur. C'est assez varié.

Fin de l'enregistrement.

Pour citer l'entretien :

« Entretien avec Sébastien Gauthier », par Xavier Guchet et Sacha Loeve, 16 novembre 2006, Sciences : histoire orale, /spip.php ?article2.

Pour citer l'entretien :

« Entretien avec Sébastien Gauthier », par Xavier Guchet et Sacha Loeve, 16 novembre 2006, Sciences : histoire orale, https://sho.spip.espci.fr/spip.php?article2.

Lieu : bureau de Sébastien Gauthier, CEMES, Toulouse, France.

Support : enregistrement numérique.

Transcription et édition en ligne : Sacha Loeve.