![\"Programme](\"https://www.epfl.ch/campus/art-culture/wp-content/uploads/2026/09/LES_CULTURELLES_1920x1080_programme_complet.png\")
\r\n\r\nLe projet Unearthed de l’artiste Rahel Oberhummer est une aventure visuelle et scientifique au cœur du développement de micro-organismes contenus dans le pergélisol de la montagne Muot da Barba Peider (Schafberg) en Engadine et collectés par l'Institut fédéral de recherches sur la forêt, la neige et le paysage (WSL). Cette collection préserve des micro-organismes provenant de régions menacées telles que les Alpes et l'Arctique et compte déjà plus de 2000 spécimens.
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\r\nL’artiste a sélectionné des levures, bactéries et champignons souvent vieux de 12’000 ans, qu’elle a cultivés dans son propre studio et photographiés tous les deux jours. Les différents micro-organismes sont déposés sur un fond d’agar pour qu’ils puissent se développer. Leur évolution est rapide et hasardeuse. La documentation est méthodique : plus de 13'300 photographies ont été prises représentant des instantanés de matière vivante.
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\r\nDeux séries de photographies ont été produites : l’une se concentre sur des monocultures, dans lesquelles une souche microbienne sélectionnée occupe une boîte de Pétri et se propage largement. En adaptant les méthodes d'inoculation et les milieux de culture, différentes impulsions sont déclenchées. La deuxième série fait cohabiter plusieurs organismes différents. La lutte pour les nutriments dans le milieu de culture ainsi que les symbioses qui peuvent se développer entre les microbes sont documentées. La pratique d’atelier se mêle à la pratique de laboratoire.
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\r\nL’exposition
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\r\nL’exposition Unearthed présente 18 photographies de plusieurs micro-organismes différents évoluant dans les boîtes circulaires qui les abritent. Filaments, textures, entrelacs, pointillés, cercles produisent des configurations abstraites spectaculaires. Les couleurs enchantent et vivifient les formes en turbulente circulation et en constante métamorphose. Les photographies pointent le sublime de l’extraordinaire variété des cellules : la naissance du vivant.
\r\nLes photographies de Rahel Oberhummer révèlent deux nécessités indissociables : d’une part celle de comprendre le vivant même dans ses organismes les plus simples et d’autre part de le préserver. Parallèlement, il s’agit de créer des images qui manifestent la qualité visuelle des formes et des couleurs de ces micro-organismes. Notre rapport à la nature exige l’admiration de sa beauté. Aujourd’hui, des artistes comme Rahel Oberhummer s’engagent dans une double mission : participer activement à des processus scientifiques et créer des images sensibles tout autant que savantes.
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\r\nCollaborations
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\r\nSérie photographique réalisée en collaboration avec l’Institut fédéral de recherches sur la forêt, la neige et le paysage (WSL). Unité : Biodiversité et écologie de la conservation.
\r\nDr. Beat Frey, Dr. Joel Rüthi, Dr. Ivano Brunner, Beat Stierli
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\r\nEléments biographiques
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\r\nRahel Oberhummer (*1991, Loèche-les-Bains) est diplômée de la HEAD, Genève. Elle a étudié aussi à la Royal Danish Academy of Fine Arts, Copenhague, à la Hochschule für Kunst und Design de Lucerne et au Billy Blue College of Design à Sydney. Au début de l’année 2026, elle a obtenu une résidence de trois mois à Hanoï, au Vietnam, dans le cadre d’un séjour de recherche soutenu par Pro Helvetia et accueilli par l’espace Exutoire. Elle vit et travaille à Vevey.
\r\nLa relation entre les structures sociales humaines et les formes de vie non humaines est au cœur de son approche artistique. Rahel Oberhummer se concentre sur les interactions subtiles entre les humains et l'environnement, avec une attention soutenue pour les écosystèmes dont nous dépendons et que nous mettons pourtant en danger. Des questions se posent, que l'artiste explore à travers une recherche scientifique autant qu’artistique.
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\r\n>>> Site web de l'artiste Rahel Oberhummer
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\r\nVernissage le jeudi 7 mai 2026 à 18 :30
\r\nExposition visible jusqu’au 11 octobre 2026
\r\nHall du RLC / entrée libre
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\r\nImage : Dioszegia patagonica 001, Pochonia/Metacordyceps chlamydosporia 205, Pseudogymnoascus pannorum 511, Potato Dextrose Agar with sepia ink, 2022.
\r\n\r\nRecent reports claim that hydrogen peroxide (H2O2) is spontaneously generated – without external energy input or catalyst – at the air–water interface of microdroplets1, bubbles2, and soap films3. Several mechanisms have been proposed to explain this phenomenon, including: (i) ultrahigh instantaneous electric fields at the air–water interface driving HO− à HO• + e− radicals from hydroxide ions; (ii) water’s comproportionation into H2O•+ and H2O•−; and (iii) partial dehydration of interfacial H+ and HO− followed by radical formation. In contrast, our laboratory experiments reveal that H2O2 formation is due to the reduction of dissolved O2 at water– solid interfaces, i.e., with no role for the air–water interface beyond O2 mass transport4-6. Based on these findings, I will present four diagnostic criteria against which any existing or future mechanistic proposal should be assessed. Our approach reconciles the claims of spontaneous H2O2 formation within established physical chemistry and extends naturally to other claims of anomalous microdroplet reactivity.
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\r\nReferences:
\r\n(1) Mehrgardi, M. A.; Mofidfar, M.; Zare, R. N. Sprayed Water Microdroplets Are Able to Generate Hydrogen Peroxide Spontaneously. Journal of the American Chemical Society 2022, 144 (17), 7606-7609. DOI: 10.1021/jacs.2c02890.
\r\n(2) Nami-Ana, S. F.; Mehrgardi, M. A.; Mofidfar, M.; Zare, R. N. Sustained Regeneration of Hydrogen Peroxide at the Water-Gas Interface of Electrogenerated Microbubbles on an Electrode Surface. Journal of the American Chemical Society 2024, 146 (46), 31945-31949. DOI: 10.1021/jacs.4c11422 From NLM PubMed-not-MEDLINE.
\r\n(3) Eldeeb, A. M.; Berbille, A.; Dick, J. E. No Microdroplets? No Problem. Soap Films Amplify the Interface and Produce Hydrogen Peroxide. Journal of the American Chemical Society 2025, 147 (37), 33325-33329. DOI: 10.1021/jacs.5c05887.
\r\n(4) Eatoo, M. A.; Mishra, H. Busting the myth of spontaneous formation of H2O2 at the air-water interface: contributions of the liquid-solid interface and dissolved oxygen exposed. Chemical Science 2024, 15 (9), 3093-3103. DOI: 10.1039/d3sc06534k From NLM PubMed-not-MEDLINE.
\r\n(5) Eatoo, M. A.; Wehbe, N.; Kharbatia, N.; Guo, X.; Mishra, H. Why do some metal ions spontaneously form nanoparticles in water microdroplets? Disentangling the contributions of the air-water interface and bulk redox chemistry. Chemical Science 2025, 16 (3), 1115-1125. DOI: 10.1039/d4sc03217a From NLM PubMed-not-MEDLINE.
\r\n(6) Eatoo, M. A.; Mishra, H. Disentangling the Roles of Dissolved Oxygen, Common Salts, and pH on Spontaneous Hydrogen Peroxide Production in Water: No O2, No H2O2. Journal of the American Chemical Society 2025, 147 (39), 35392-35400. DOI: 10.1021/jacs.5c09028.
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\r\nPapers:
\r\n- Busting the myth of spontaneous formation of H2O2 at the air–water interface: contributions of the liquid–solid interface and dissolved oxygen exposed
\r\n- Disentangling the Roles of Dissolved Oxygen, Common Salts, and pH on Spontaneous Hydrogen Peroxide Production in Water: No O2, No H2O2
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\r\nBio: Himanshu Mishra is a scientist-entrepreneur from King Abdullah University of Science and Technology (KAUST), Saudi Arabia. His team has significantly contributed to resolving scientific debates surrounding the spontaneous H2O2 formation in water microdroplets, the electrification at water-hydrophobe interfaces, and liquid–solid adhesion forces. Mishra’s team has also pioneered Carbosoil™ technology to transform desert soils for sustainable greening, food production, and carbon sequestration. His start-up Terraxy is now scaling up Carbosoil™ production to advance sustainability projects in the Middle East and beyond. Mishra’s efforts have been featured by the World Economic Forum, Geneva Inventions, and CNN (LINK).
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Atomically precise carbon nanostructures offer a new route to quantum systems built from the bottom up. By combining molecular design, on-surface synthesis and scanning probe microscopy, we can control atomic structure, electronic states and magnetic interactions within the same platform.
\r\nIn this talk, I will follow the path from bottom-up synthesized graphene nanoribbons [1,2] to open-shell nanographenes [3] and designer quantum spin systems [4]. I will discuss how atomic structure can determine electronic topology and how molecular spins can be coupled into well-defined quantum chains. Recent examples include Haldane chains [4], alternating-exchange spin chains [5] and antiferromagnetic Heisenberg chains [6], where collective and fractional excitations can be probed directly at the atomic scale.
\r\nMore broadly, this work illustrates a materials-science strategy in which structure, functionality and interactions are programmed at the level of molecular building blocks. Rather than optimizing properties in an existing material, the aim is to design the material and its quantum behavior together. Atomically precise carbon nanostructures therefore provide a model platform for exploring how synthesis, structure and emergent functionality can be linked in a predictive way, with implications for the future design of low-dimensional electronic, magnetic and quantum materials.\r\n
Biological systems have already paved several routes for bioinspired materials, e.g., for structural colours, wetting, adhesion, and mechanical properties. They have largely involved equilibrium or kinetically trapped properties. By contrast, biological systems allowing multifunctional properties are characteristically dissipatively and dynamically adaptive and incorporate homeostatic feedback mechanisms to regulate the dynamic states. They also typically use signal transduction to mediate the signal from the sensory elements to the responsive sites, unlike the classic man-made stimuli responsive materials. These concept suggest avenues towards more complex life-like functions in soft matter. Herein, optically driven hydrogel systems are presented to drive homeostatically controlled thermal oscillations and to mediate signal transduction via thermal intermediate signalling (1). On the other hand, biological magnetoreception in elasmobranch organisms involves electromagnetic induction (EMI) and suggests avenues for bioinspired electrical signal transductions. We show magnetic profile recognition of translocated magnetically encoded soft matter objects using electrical intermediate signaling by EMI and decoding the magnetic information with machine learning (2). Combination of high stiffness and promoted dynamics for self-healing has turned challenging to combine. Self-healing hydrogels, still combining high tensile stiffness close to that of skin were shown by using polymers upon nanoconfinement in 2D-nanosheet layered confinements (3). Finally, we show trainable actuations in bilayer gel actuators (4). Ever more complex responses can be created, such as mimicking the Pavlovian classical conditioning (5), all paving ways for growingly life-like functions for soft robotics and interfacing with biology.
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\r\n1. H. Zhang, H. Zeng, A. Eklund, H. Guo, A. Priimagi, O. Ikkala, Feedback-controlled hydrogels with homeostatic oscillations and dissipative signal transduction, Nat. Nano, 17, 1303 (2022).
\r\n2. Z. Miao, X. Hu, K. Liu, S. Hu, G. Yan, H. Tan, O. Ikkala, Z. P. Lv, B. Peng, Bioinspired sensory transduction for magnetic profile recognition and encryption, Adv. Mat. 38 e15994 (2026).
\r\n3. C. Liang, V. Dudko, O. Khoruzhenko, X. Hong, Z.-P. Lv, J. Breu, O. Ikkala, H. Zhang, Stiff and self-healing hydrogels by polymer entanglements in co-planar nanoconfinement, Nat. Mater. 24, 599 (2025).
\r\n4. S. Hu, Y. Fang, C. Liang, M. Turunen, O. Ikkala, H. Zhang, Thermally trainable dual network hydrogels, Nat. Commun., 14, 3717 (2023).
\r\n5. H. Zhang, H. Zeng, A. Priimagi, O. Ikkala, Programmable responsive hydrogels with classical conditioning algorithm, Nat. Commun., 10, 3267 (2019).
Prof. Emilio Carlos de Lucca Junior - Associate Professor at Institute of Chemistry – University of Campinas
","image_description":"","creation_date":"2026-08-24T15:40:53","last_modification_date":"2026-09-15T11:14:45","link_label":"","link_url":"http://www.researcherid.com/rid/B-9203-2017","canceled":"False","cancel_reason":"","place_and_room":"Salle Génopode","url_place_and_room":"","url_online_room":"","spoken_languages":["https://memento.epfl.ch/api/v1/spoken_languages/2/?format=json"],"speaker":"Prof Emilio C de Lucca, Jr. (University of Campinas, Brazil) ","organizer":"Prof. Jieping Zhu","contact":"Jieping Zhu, Souad Di Meo","is_internal":"False","theme":"","vulgarization":{"id":1,"fr_label":"Tout public","en_label":"General public"},"registration":{"id":3,"fr_label":"Entrée libre","en_label":"Free"},"keywords":"ocseminar","file":null,"icalendar_url":"https://memento.epfl.ch/event/export/121557/","category":{"id":1,"code":"CONF","fr_label":"Conférences - Séminaires","en_label":"Conferences - Seminars","activated":true},"academic_calendar_category":null,"domains":[],"mementos":["https://memento.epfl.ch/api/v1/mementos/5/?format=json","https://memento.epfl.ch/api/v1/mementos/14/?format=json"]},{"id":72747,"title":"2 Billion years of shelterin and t-loops: from telomere protection to tumor suppression","slug":"2-billion-years-of-shelterin-and-t-loops-from-telo","event_url":"https://memento.epfl.ch/event/2-billion-years-of-shelterin-and-t-loops-from-telo","visual_url":"https://memento.epfl.ch/image/33962/200x112.jpg","visual_large_url":"https://memento.epfl.ch/image/33962/720x405.jpg","visual_maxsize_url":"https://memento.epfl.ch/image/33962/max-size.jpg","lang":"en","start_date":"2026-11-26","end_date":"2026-11-26","start_time":"12:15:00","end_time":"13:15:00","description":"A Lola and John Grace Distinguished Lecture in Cancer Research\r\nWe discuss a class of graph embeddings into Minkowski space R^{2,2} = C^{1,1}, called t-surfaces, which arise in the study of the planar dimer model. A t-surface consists of a (perfect) t-embedding together with its associated origami map. Perfect t-embeddings were recently introduced as a key tool for proving that the gradient of the dimer height function converges to that of the Gaussian Free Field in a canonically associated metric, under suitable technical assumptions. After introducing the notion of a t-embedding, we will describe a construction of perfect t-embeddings for regular hexagons of the hexagonal lattice. In which the corresponding t-surfaces converge to space-like maximal surfaces in Minkowski space R^{2,1}. As a consequence, these constructions yield a new proof of convergence of fluctuations of the dimer height function to the Gaussian Free Field in the conformal structure induced by the limiting maximal surface.
","image_description":"","creation_date":"2026-10-01T16:38:56","last_modification_date":"2026-10-01T16:38:56","link_label":"","link_url":"","canceled":"False","cancel_reason":"","place_and_room":"CM 1 517","url_place_and_room":"https://plan.epfl.ch/?room==CM%201%20517","url_online_room":"","spoken_languages":["https://memento.epfl.ch/api/v1/spoken_languages/2/?format=json"],"speaker":"Marianna Russkikh","organizer":"Prof. Martin Hairer","contact":"Juliana Velasquez","is_internal":"False","theme":"","vulgarization":{"id":2,"fr_label":"Public averti","en_label":"Informed public"},"registration":{"id":3,"fr_label":"Entrée libre","en_label":"Free"},"keywords":"","file":null,"icalendar_url":"https://memento.epfl.ch/event/export/122018/","category":{"id":1,"code":"CONF","fr_label":"Conférences - Séminaires","en_label":"Conferences - Seminars","activated":true},"academic_calendar_category":null,"domains":[],"mementos":["https://memento.epfl.ch/api/v1/mementos/7/?format=json","https://memento.epfl.ch/api/v1/mementos/403/?format=json"]},{"id":72764,"title":"IMX Talks - Resolving Hierarchical Structure with X-ray scattering imaging","slug":"imx-talks-resolving-hierarchical-structure-with-x","event_url":"https://memento.epfl.ch/event/imx-talks-resolving-hierarchical-structure-with-x","visual_url":"https://memento.epfl.ch/image/33978/200x112.jpg","visual_large_url":"https://memento.epfl.ch/image/33978/720x405.jpg","visual_maxsize_url":"https://memento.epfl.ch/image/33978/max-size.jpg","lang":"en","start_date":"2026-11-02","end_date":"2026-11-02","start_time":"16:30:00","end_time":"17:30:00","description":"The function of many materials, from biological tissues to industrial polymers, depends on how their nanoscale building blocks are arranged and aligned within a macroscopic structure, which is essential to understand but difficult to resolve: established high-resolution techniques typically access only small sample volumes, limiting the ability to capture structural or biological variability across extended, heterogeneous samples.
\r\nSmall-angle X-ray scattering (SAXS) imaging probes local nanostructure by raster-scanning a focused synchrotron beam across a sample. This can be extended to resolve nanostructure orientation voxel-by-voxel in three dimensions in a method called SAXS tensor tomography, which we implement in our open-source software package Mumott. In this presentation, I will show how this approach, and its continued development, can be applied across different material systems.
\r\nFor injection-molded polymer packaging, SAXS imaging has resolved the layered anisotropic nanostructure important for its mechanical properties, and, combined with industrial processing simulations, the structure formation during thermal processing. Another example is bone, where resolving structure requires both three-dimensional information and sufficient sampling to capture biological variability. Combining 2D and 3D SAXS imaging, we studied regional differences in the human femoral neck, an anatomical site relevant to hip fractures, and, at higher resolution, resolved alternating chirality between neighboring lamellae within individual osteons, a structural feature proposed on mechanical grounds over a century ago.
\r\nThese examples illustrate how tensor tomography, extended beyond X-ray scattering to wide-angle diffraction and visible-light polarimetry, provides a route to resolving hierarchical structure across a wide range of material systems.
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\r\nBio: Marianne Liebi studied food science at ETH Zurich, where she also completed her PhD in 2013, followed by postdoctoral research at the Paul Scherrer Institute and MAX IV Laboratory, Lund. In 2017, she started her own research group at Chalmers University of Technology, Gothenburg, and was appointed in 2021 as tenure-track Assistant Professor at EPFL, where she heads the Laboratory for X-ray Characterization of Materials (cam-X) within the Institute of Materials, in a joint position with the Paul Scherrer Institute (PSI). Her research develops advanced X-ray and optical imaging techniques, centered on small-angle X-ray scattering (SAXS) in 2D and 3D, to resolve the hierarchical structure of materials ranging from fiber composites to pharmaceutical formulations and bone.