Dresden 2020 – wissenschaftliches Programm
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BP 18.18: Poster
Dienstag, 17. März 2020, 14:00–16:00, P2/2OG
Stick-slip motion for a cellular glider with translational and rotational friction — •Pintu Patra1,2, Anna Battista1,2, and Ulrich S. Schwarz1,2 — 1BioQuant, Heidelberg University & University Medical School, Heidelberg, Germany — 2Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
Cellular movement over planar surfaces is often limited by sliding friction at the cell-substrate interface. A typical feature of sliding friction is stick-slip motion which consists of periods of slow (stick phase) and fast movement (slip phase). Stochastic multi-contact models explain the observed stick-slip motion at intermediate speeds of the translational motion. These models consider an ensemble of molecular bonds that form and rupture at the interface between two surfaces moving relative to each other. Here we extend this theoretical framework to include also the effect of rotational motion, a situation which arises e.g. for malaria parasites gliding on flat substrates. First, we derive analytical force-velocity and torque-angular velocity relations for pure translation and pure rotational driving, respectively. Then we show that a critical region of large bond fluctuations observed for the combined driving smoothly connects the corresponding regimes that exist for the purely translational and purely rotational cases. We also find an additional regime at small translational but high rotational velocities in which large deviations occur in the circularity of the cellular glider.