![\"Programme](\"https://www.epfl.ch/campus/art-culture/wp-content/uploads/2026/09/LES_CULTURELLES_1920x1080_programme_complet.png\")
\r\n\r\nThesis Director: Prof. J. Waser,
\r\nChemistry and Chemical Engineering doctoral program
\r\nThesis Nr. 12072
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\r\nTo take part in the public defense, please contact directly the speaker
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.
Chirality is omnipresent in nature through a fundamental coupling between chirality and angular momentum. Despite extensive experimental evidence, the underlying mechanisms of this coupling remain debated. Here, we will explore how chiral magnetic textures can be stabilized in altermagnets, a new class of magnetism. Turning to structurally chiral magnetic molecules, we will show that chirality is directly linked to their intrinsic magnetic moments. Bringing both together, we will discuss how molecular design can control spin phenomena at hybrid chiral molecule-magnet interfaces. Our findings pave a pathway towards functional \"chiraltronic\" devices – turning a fundamental puzzle into a technological opportunity.
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\r\nMicrosystems and Microelectronics doctoral program
\r\nThesis Nr. 11398
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\r\nTo take part in the public defense, please contact directly the speaker
The Doctoral School is glad to invite all first-year PhD candidates to join the annual PhD Welcome Event!
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\r\nWhat to expect:
\r\n- Meet the EPFL doctoral community, the administrators of the doctoral school and programs, the PhD associations
\r\n- Discover the many EPFL services dedicated to supporting and counseling students and researchers
\r\n- Get useful insights about your doctoral journey at EPFL, and the resources available to help you
\r\n- Enjoy free food & drinks, and connect with PhD candidates from all our programs and campuses!
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\r\nWho is it for?
\r\n- The event is open to EPFL PhD candidates who enrolled after November 2025. Registration is required.
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\r\nPhD candidates working outside Lausanne are especially encouraged to join. This event is a golden opportunity to discover the Lausanne campus and meet your peers! You may request travel support: please contact us via the registration form.
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\r\nDirect link to the registration form
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\r\nWe look forward to meeting you on November 5th!
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\r\nThe Doctoral School Administration Team (EDOC)
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In migrating cells, the GTPase Rac organizes a protrusive front, whereas Rho organizes a contractile back, yet how these GTPases segregate remains unclear. We leverage optogenetics, mechanical perturbations, and modeling to reveal a mechanochemical long-range mutual activation between front and back polarity programs that complements their known local mutual inhibition. Rac-driven protrusions increase membrane tension, triggering mTORC2-dependent Rho activation at the opposite side of the cell. Conversely, Rho-mediated contractility induces cortical-flow regulation of phosphoinositide signaling, promoting distal Rac activation. Our findings demonstrate how the actin cortex and plasma membrane interact as an integrated mechanochemical system for long-range Rac-Rho patterning. Efficient migration also requires polarized organization of the cell interior, with organelle positioning increasingly recognized as a key determinant of cell movement. Yet how this organization is established remains unclear. Building on our mechanochemical framework, we now investigate how actin-generated forces position organelles during migration and how disruption of this intracellular organization contributes to disease.
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\r\nWebsite of the De Belly lab: https://cri.utsw.edu/faculty/henry-de-belly/
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\r\nThis is part of the Physics of Living Systems monthly symposium: https://pols.epfl.ch/physics-of-living-systems-seminars/monthly-symposium/
Lysosomes sit at the crossroads of cellular catabolism and quality control, where they must dismantle chemically diverse cargo while preserving their own integrity. I will discuss two discoveries that reveal how lysosomes solve these complementary challenges and how their failure creates disease vulnerabilities. First, I will describe Lysosomal Leucine Aminopeptidase (LyLAP), an enzyme specialized to processively degrade the hydrophobic α-helices of transmembrane proteins. LyLAP is highly expressed in pancreatic ductal adenocarcinoma, where its loss causes hydrophobic peptides to accumulate, compromises lysosomal function, and ultimately leads to cancer cell death, revealing a potential vulnerability in tumors with elevated endocytic activity. I will then describe LASER, a damage-responsive protein assembly that couples lysosomal membrane injury to repair. At its core, the oligomeric protein TFG recognizes LC3/GABARAP proteins conjugated to damaged lysosomes and recruits the ESCRT machinery to restore membrane integrity. Neurodegenerative disease-associated mutations in TFG disrupt this process, linking defective lysosomal repair to human disease. Together, these findings reveal lysosomes as dynamic systems that coordinate cargo degradation with membrane surveillance and repair to maintain cellular homeostasis.
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\r\nMore about Dr. Aakriti Jain's lab at UTSW: https://aakritijainlab.com/
Thanks to a donation from the Claude Latour Foundation, the Pôle Culture (VPI) is organizing a master class followed by a public concert based on the Verbier Festival archives, which are being digitized at EPFL by the EPFL Cultural Heritage & Conservation Platform (CHC).
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\r\nDuring the masterclass, the selected students are invited to create a musical piece lasting no more than 5 minutes in the style, aesthetic, and genre of their choice (jazz, rap, rock, metal, classical, etc.). At the end of the day, the pieces will be presented to the public, accompanied by comments from a panel of experts.
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\r\nPROGRAM:\r\n
\r\n\r\nAn opportunity to celebrate the end of the year and share quantum research at EPFL with one another and the larger community. The event will include short lectures on topics in quantum for the general community, optional lab visits, and food and drinks!
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\r\nFull program and registration available in October