The SLAM - Smart, Living, & Active Matter - initiative unites theory and experimental groups of the Leiden Institute of Physics. It currently gathers the groups of Luca Giomi, Louise Jawerth, Daniela Kraft, Martin van Hecke, Silke Henkes and Alexandre Morin.
The SLAM symposium on Active Solids which took place on June 4th was a succes!
Title: Mechanics of Morphogenesis: flow versus “morphing”.
Abstract Morphogenesis is a developmental process through which plants and animals acquire their shape and form. This talk will focus on tissue mechanics underlying massive transformations in the shape of epithelial tissues during gastrulation of animal embryos. This transformation of tissue is often described in terms of a (visco-elastic) flow of cells driven by active, myosin motor generated, internal forces. Yet, despite their apparent “fluidity” epithelial tissues can support shear stress, so a deeper examination is in order. This talk will argue that morphogenetic transformations of tissues can be understood in terms of an adiabatic remodeling of the force balance governed by myosin motor activity and controlled by feedback. The ability of cells to directly control active cytoskeletal tension -much like muscles - deprives tissue mechanics of a constitutive relation, pulling the rug under conventional elasticity as a starting point for a theory. This talk will formulate an alternative continuum mechanics of Active Solids, that will exhibit “emergent elasticity” on large scales and provide a principled description of active plastic flow as controlled “morphing” transformation of shape that takes place on the force-balanced manifold. This new theory of Active Solids will also provide an example of how the study of biological phenomena pushes the envelope of Physics beyond what we have learned from textbooks.