Winner of the 2023 CNRS Silver Medal, Alexander Kuhn has left his mark on the scientific community with his work in electrochemistry, which touches on fields from the pharmaceutical industry to robotics. Meeting with a hypercreative researcher who passionately experiments.
Behind his desk, a series of prices are displayed on the wall and on the chest of drawers that serves as a display. So many trophies testifying to an impeccable journey. Alexander Kuhn is somewhat the archetype of the scholar we imagine him to be, an expert in his field, with prolific creativity. ” Connects things quickly. He is one of the most creative chemists I know. », describes Laurent Bouffier, his colleague at the Institute of Molecular Sciences (ISM) in Bordeaux. And this singularity works for him. ” There are several ways to research. In 90% of cases you are implementing, in other words, marginally improving what has already been done before. But his research does not follow this pattern. The ideas he develops are original and he likes to crack codes », continues Laurent Bouffier.
Over a thirty-year career, Alexander Kuhn left his mark on the scientific community with his discoveries, among other things, on chiral molecules and a relatively little-known technique: bipolar electrochemistry.
Between chemistry, physics and biology
Batteries, photovoltaic cells, fuel cells… all these industrial products are based on principles based on electrochemistry, a flourishing discipline that is interested in the relationship between chemistry and electricity and that also enables the production of “green” hydrogen and synthetic molecules for pharmaceutical industry. Currently, the researcher is focusing on this last aspect.
Next to the chemist’s desk is a blue plastic spiral, a typical chiral object: the object and its mirror image cannot overlap. Alexander Kuhn and his team could revolutionize the way drugs are manufactured thanks to their work on chiral molecules.
As a first step forward, Alexander Kuhn’s research provided a new perspective on ways to produce drugs for which chiral molecules serve as active ingredients (a chiral molecule has two configurations, or two enantiomers, which, like our two hands, are perfectly identical except that they are mirror images of each other, but cannot overlap, editor’s note). Their synthesis usually leads to a half-half mixture of two enantiomers that has antagonistic effects. ” Only one of the two enants has therapeutic efficacy. Others don’t have them or can be poisonous and even kill “, explains Alexander Kuhn.
The process proposed by the researcher and his team allows the selective synthesis of the right enantiomer, without the need to sort mixtures. Enough to disrupt the classic processes of pharmaceutical laboratories, which are obliged to classify them when making mixtures. “ So far we have studied model molecules, but for three years now we have been working on real molecules of pharmacological interest, such as adrenaline, for example, and this also works. », greets the chemist.
An experiment that illustrates the principle of bipolar electrochemistry: the preparation of a thin film of a biocompatible polymer by electrochemical means, which will then serve as the basic ingredient for the design of an artificial muscle, capable of autonomously changing its shape in the presence of sugar and oxygen.
Another advance: the principle of bipolar electrochemistry, which illustrates this side step that Alexander Kuhn manages to take in his work. Where conventional electrochemical reactions require electrodes directly connected to a source of electricity, he had the idea of placing a conductive object between the electrodes. It is the electric field that is created around the object that will initiate electrochemical reactions. A real conceptual change that allows us to imagine applications unimaginable without this trick, for example deforming a soft material at a distance, like plastic, with an electrical signal – in a way similar to the movement our muscles make when they respond to a nerve signal produced by our brain. For example, the team recently developed a miniaturized system based on a biocompatible conducting polymer that, using sugar, oxygen, and an electromechanical reaction, is capable of autonomously changing its shape and generating periodic motion that resembles a heartbeat.
Experimental artist
If the producers like his work, the researcher does not think about social impact, results or productivity: “ I like to play with ideas and concepts. What interests me is creation. If you think too much about the future application, it limits your imaginationassures. Sometimes my searches turn up nothing. I am very selfish, I became a researcher because my only motivation is fun “, jokes the one who ” hates projects where you already have to predict exactly what you will get. At first, the laser was a laboratory curiosity. No one thought that it would later be useful for eye surgery, reading a CD or cutting a sheet metal. Most discoveries don’t come from process from top to bottomit is quite the opposite “.
Discussion with Dr. Gerard Salinas, postdoctoral student, on the morphology of chiral Janus particles (dissymmetric particles), synthesized by bipolar electrochemistry and characterized by scanning electron microscopy.
Alexander Kuhn readily admits that his discoveries are often inspired by everyday life or the nature that surrounds us. While walking in his garden, he came up with the idea of developing a drive strategy based on the natural photosynthesis of plants.
At the age of 15, Alexander Kuhn set up a laboratory in the basement of his family home near Munich. At the age of 16, he received first prize at the national level in the German competition “Jugend forscht” for his work on polymers that conduct electricity.
To achieve this, he applied microsurgery to one of the veins of the tree’s leaf to free its outlet. Immersed in water and in contact with light, the leaf whose structure had been modified began to move thanks to the targeted release of oxygen produced during photosynthesis. Unlike most systems reported so far, no chemical fuel was required to power the film. If you ask him why he would do such a thing, Alexander Kuhn’s answer is troubling: “ It’s art for art’s sake “, he explains.
Alexander Kuhn has been performing experiments since childhood. ” I always knew I wanted to become a chemist “, he assures. At the age of 15, he set up a laboratory in the basement of his family home near Munich, Germany, to carry out his experiments on polymer materials. ” I was fully equipped. I put all my pocket money into it. I had my own flasks, my own distillation columns, and I asked companies to send me donations of solvents. I explained to them that I was a young scientist and sent them letters asking them to fund my research. To my surprise, it worked very well. “. And for good reason, at the age of 16 he won the first prize at the national level in the German competition “Jugend forscht” for his work on polymers that conduct electricity.
The electrochemist’s ideal
After studying chemistry in Munich, Alexander Kuhn arrived in France in the early 1990s to complete his thesis at the Paul Pascal Research Center near Bordeaux. There, the metal will “grow” through an electrochemical reaction, similar to the branches that grow on a tree: ” the idea was to understand the growth logic of tree structures. We wanted to know if we could identify explanatory patterns for these phenomena. “, he says.
On the board, Alexander Kuhn schematizes the concept of bipolar electrochemistry for the specific case of a semiconductor particle, which behaves opposite to a conducting particle.
He then went to the United States, to the California Institute of Technology (Caltech) for a postdoctoral fellowship that he describes as ” the best moment in my career » : « I had the ideal life of a scientist. I enjoyed complete intellectual and financial freedom. I had no funds to find, no administrative tasks, no big responsibilities. Now my responsibilities are no longer the same », admits the chemist. Twenty years later, Alexander Kuhn’s daily tasks are now divided between teaching, research and seeking funding for his work within the ISM. A limitation for this creative person for whom research is anything but planning, although scientific research is increasingly leaning towards this model.
Electrochemistry is the science of the 21st centurye century. If we want to find a solution to our ecological and technological problems, we cannot do without them.
This professor at the National School of Materials, Agriculture and Chemistry must also strive to continue promoting this work. ” One of the challenges we face to ensure the democratization of our processes in the future is that scale up, in other words a change of scale. Some of the ideas we have implemented work on a laboratory scale, but not on an industrial production scale. There are technological hurdles that need to be addressed, such as optimizing electrode performance, lifetime, and improving material transport in solution “, he enumerates. ” PFor me, electrochemistry is the science of the 21st centurye century. If we want to find a solution to our environmental and technological problems, we cannot do without it “, he is convinced.
Sometimes Alexander Kuhn also finds himself dreaming about new processes. One of his hopes would be, like every (electro)chemist in the 21st centurye centuries of self-respect, transform carbon dioxide (CO2) into something useful. If we can develop an electrochemical process that allows us to remove this gas from the atmosphere and reuse it, we will kill two birds with one stone in the fight against global warming. », he is delighted. Believing in your dreams and making them come true seems to be second nature to Alexander Kuhn. And this dynamic will obviously not stop. ♦