The separation of elongated and/or deformable particles, such as microplastic fibers or pathogens, using structured media, such as pillar arrays, is essential for many processes such as pollution control, environmental assessments, diagnosis or biological analysis. However, it remains a highly challenging task due to the extensive range of morphologies fibers can adopt when interacting with flows and obstacles. Predicting and controlling the trajectory of elongated elastic structures in a flow embedded with obstacles is essential to understand the physics of biological and industrial systems but also to design efficient separation techniques. The aim of this project is to investigate the migration of flexible fibers due to pressure-driven flows in structured media embedded with obstacles using theoretical models and numerical simulations. The intern will use theoretical analysis and numerical tools developed by the group of Blaise Delmotte at LadHyX, and will collaborate closely with the groups of Olivia du Roure and Anke Lindner at PMMH, where experiments are performed.