According to a CNRS publication dated November 5, 2025. Based on a scientific publication in Nature Communications to which Stéphane Santucci, a CNRS researcher at ENS de Lyon’s Physics Laboratory (LPENSL), contributed: Multiscale stress dynamics in sheared liquid foams revealed by tomo-rheoscopy. Thumbnail credit: © CNRS
By observing sheared foam under a time-resolved X-ray tomograph, physicists were able to observe how the rearrangements of bubbles in flow cause the overall mechanical response of the entire system.
Rheology studies how materials react to mechanical stresses. However, conventional techniques only provide global information (such as viscoelastic moduli), without access to what is happening at the microscopic level. This severely limits our understanding of certain complex materials such as amorphous materials known as "soft jammed" materials. These materials, such as pastes, emulsions, foams, etc., have their elementary constituents (grains, droplets, bubbles, etc.) densely confined by their neighbors. However, under stress, these elements can become unblocked and reorganize, giving rise to highly heterogeneous deformations and complex structural rearrangements.
To better capture these internal dynamics, researchers from an international collaboration involving three CNRS physics laboratories have developed a new experimental approach called tomo-rheoscopy, which combines a shear device with time-resolved 3D X-ray tomography, and applied it to liquid foams.
Read more on the CNRS website
Reference
Multiscale stress dynamics in sheared liquid foams revealed by tomo-rheoscopy, Schott, F., Dollet, B., Santucci, S. et al, DOI: 10.1038/s41467-025-64412-z
