Sommaire:

Self-assembly and aggregation of soft condensed matter like proteins, colloids or polymers into
poorly connected and weakly elastic solids is very common and ubiquitous in nature. Phase separa-
tion, spinodal decomposition as well as externally driven self-assembly or aggregation often lead to
gels, which display diverse structures and solid-like mechanical features. The structural complexity of
soft gels entails a versatile mechanical response that allows for large deformations, controlled elastic
recovery and toughness in the same material. A limit to exploiting the potential of such materials
is the insufficient fundamental understanding of the microstructural origin of the bulk mechanical
properties. Investigating how the mechanical response depend on the material microstructure will
provide a new rationale, which would ultimately lead to several applications, ranging from improving
the performance of batteries (colloidal gels), designing smart composites that can prevent the cascade
of catastrophic events and can be used in anti-seismic buildings, and many with important biological
function, such as new scaffolds for tissue engineering.
In the first part of my talk, using numerical simulations of a minimal model, I will present the link
between the topology of the network and the non-linear rheological response: our analysis elucidates
how the network connectivity alone could be used to modify the gel mechanics at large strains, from
strain-softening to hardening and even to a brittle response. Then I will show the relevance of our
model to understand the mechanics of F-actin cytoskeleton. Our study helps to clarify, the mechanism by which mutations cause podocyte dysfunction and progressive kidney disease in humans.

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Pour plus d'informations, merci de contacter Parmeggiani A.