Our paper on the linear rheology of foam is now out in the Journal of Chemical Physics and available in open access here. We show that the deformation under stress of a commercial shaving cream (Gillette) is a sum of an elastic, a fluid, and a power-law contribution which is time-reversible and reminiscent of so-called “delayed elastic” behaviour. Using analytical models and results of linear rheology, we show how delayed-elastic effects are responsible for peculiar slow relaxation dynamics that have attracted attention for many years. A full dataset and details about the foam structure and rheology are also available in open access.
Viewpoint article, published today in Physics!
I am discussing very cool research by Denis Bartolo and colleagues in Lyon and Paris on the appearance of traffic jams. In short: traffic jams appear in dense crowds very much like ice cubes form in freezing water.
Their experiment does not involve people, but millions of tiny beads that roll together on a track, in well controlled conditions. Their conclusion is that very large traffic jams may form only because people tend to slow down when surrounded by too many others. These results need to be taken into account when designing smart cars to make them avoid the conditions of traffic jam formation.
Suitable for anybody with an interest in science, not a specialist article. To know more, click here.
Invited Talk at CECAM workshop
On Friday June 28th 2019, I will give an invited talk at the CECAM workshop “Emerging behaviour in active matter: computational challenges”, at Lincoln, UK. The talk will be about the motility-induced cohesion of active particles with perception-dependent motility.
I wish to dedicate this talk to the memory of my grand father, Henri Merle, who passed away on June 25th, 2019. He will be greatly missed.
New article in EPJB!
A new paper on grain boundary migration is now available in EPJB in open access! To see it, follow this link. We look at the shrinkage of grain boundary loops in colloidal crystal and directly evidence the presence of different mechanisms. We discuss the importance of curvature-driven shrinkage, grain boundary sliding, and coupled migration.
New publication in Science!
My work on active matter performed in the group of Clemens Bechinger at the University of Konstanz is published in Science today. With coworkers Hugo Wendehenne and Tobias Bauerle, we show how the cohesion of groups can be explained by the combination of long range vision and motion when crowded regions are in sight. We used this mechanism to aggregate dozens of motorised colloidal particles into cohesive groups. We hope that our findings can be used to achieve robust and scalable aggregation of autonomous robots.
http://science.sciencemag.org/content/364/6435/70.editor-summary
Arrival in Fribourg!
Since 01.03.2019, I am now a postdoc at the Department of Physics of the University of Fribourg in Switzerland. I am working on the failure of soft materials with Dr. Véronique Trappe, within the Soft Matter and Photonics group of Prof. Frank Scheffold.
New article on grain boundary loops published in PNAS today!
Text available ahead of print here.
PRX on anomalous grain growth available online!
Click here to access the full text.
New paper on anomalous grain growth to be published in Physical Review X
My PhD work on anomalous grain growth in the Dullens group at Oxford has been accepted by PRX for publication. While the paper is still in press, you can still read the abstract by clicking here.
Move to Konstanz!
The Bechinger group will be officially starting at the University of Konstanz in October. Please visit the new website by clicking here.
Konstanz is a beautiful German old town close to the boarder with Switzerland and on the shores of the beautiful lake named after it. It is also a university town providing a very nice environment for studies and research.
François A. Lavergne 