MPIDS Colloquium: Substrate-based self-propulsion of biological cells and polymeric fibers
14:15 - 15:15
Dr. Falko Ziebert
University of Heidelberg, Germany
Max-Planck-Institut für Dynamik und Selbstorganisation (MPIDS)
Seminar room 0.77
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, like swimming bacteria and crawling eukaryotic cells, having to move to survive and/or to fulfill their function. As living systems are complex (as social perception and/or biological regulation pathways are often involved in determining their behavior on multiple scales) several biomimetic and artificial systems have been recently proposed. Most of these, however, are microswimmers, while artificial substrate-based self-propellers remain scarce.
In the first part I will give an introduction on substrate-based crawling motility of eukaryotic cells and survey our recent advances in modeling cellular motion. The developed modular approach, based on the phase field method to track the deformable and moving interfaces, allows to describe many fea-tures of motile cells, e.g., cell movement on structured substrates (with modulated adhesion or stiffness), collective cell migration, motion in 3D confinement, as well as cellular shape waves.
In the second part I present an artificial self-propeller, recently developed with experimentalists at the Institut Charles Sadron (Strasbourg). It is based on a novel mechanism to propel elastic fibers along substrates, namely a thermally induced instability towards rolling motion. The mechanism is explained by an effective model combining elasticity of a rod with thermal advection-diffusion and the versatility of the effect is exemplified by investigating the self-propulsion, as well as simple motors and energy storage devices.
F. Ziebert and I. S. Aranson, Computational approaches to substrate-based cell motility, npj Computational Materials 2, 16019 (2016).
C. Reeves, F. Ziebert et al., Rotating lamellipodium waves in polarizing cells, to appear in Comms. Phys. (2018).
B. Winkler, F. Ziebert et al., Confinement and substrate topography control 3D cell migration, under review with Phys. Rev. X (2018).
A. Baumann, F. Ziebert et al., Motorizing fibres with geometric zero energy modes, Nat. Mater., 17, 523 (2018).
F. Ziebert and I. M. Kulic, Frustriert in Bewegung (‘Motion by frustration’, in German), to be published