Dr. Falko Ziebert "Substrate-based self-propulsion in biology and soft matter systems"
Institute for Theoretical Physics, University of Heidelberg, Germany
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When |
Jun 13, 2018 from 02:15 PM to 03:00 PM |
Where | Seminarraum A, FMF, Stefan-Meier-Str. 21, Freiburg |
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Self-propulsion, i.e. self-organized motion in the absence of external forces, is an active research topic in non-equilibrium physics. Depending on the system, open questions span from the propulsive force generation and transfer, over guiding mechanisms to collective effects in ensembles of self-propellers. The living realm presents plenty of examples, from crawling cells and swimming bacteria up to animal herds, having to move to survive and/or to fulfill their function. As living systems are complex, several biomimetic physico-chemical systems have been proposed in the last decade. Most of these, however, are microswimmers while artificial substrate-based propellers remain scarce.
After a general introduction I discuss two examples for substrate-based motion: first, I will give an introduction to the crawling motility of eukaryotic cells and survey our recent advances in its modeling. A modular approach, based on the phase field method to track the deformable and moving cells, allows us to describe, e.g., cell movement on structured substrates or in confinement, and collective cell migration. I will also discuss the example of cellular shape waves, where the computational approach allows for additional insight via semi-analytic methods.
In the second part I present a novel mechanism for self-propulsion, developed in collaboration with experiments at the Institut Charles Sadron in Strasbourg: namely, a thermally induced instability of elastic polymeric fibers towards rolling motion. I explain the mechanism theoretically and demonstrate its versatility by employing it to develop a minimal motor and a simple energy storage device.
invited by Prof. Günter Reiter