Dresden 2006 – wissenschaftliches Programm

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AKB: Biologische Physik

AKB 3: Cell Motility I

AKB 3.3: Vortrag

Montag, 27. März 2006, 12:15–12:30, ZEU 255

Biomimetic flagella and cilia — •Holger Stark and Erik Gauger — Universität Konstanz, Fachbereich Physik, D-78457 Konstanz

In biological systems, small organisms move in a Newtonian fluid and fluid itself is transported with the help of beating filaments (cilia) or rotating flagella. The motion is governed by small Reynolds numbers, i.e., by a regime where inertial effects can be neglected. Thus directed motion can only occur in systems where time-reversal symmetry is broken.

Recently, Dreyfus et al. realized a one-armed swimmer [1] that fulfills these requirements. It is based on an elastic filament formed by superparamagnetic particles that are hold together by chemical linkers. Whereas real flagella or cilia are driven by internal machinery, the artificial filament is actuated by an external field. We simulate the filament using a discretized elastic-rod model where the particles also interact via dipolar and hydrodynamic interactions. We discuss two characteristic quantities, i.e., the swimming velocity and its efficiency. Furthermore, we demonstrate how the biomimetic cilium when attached to a bounding surface can be used to transport fluid.

[1] R. Dreyfus, J. Baudry, M. L. Roper, M. Fermigier, H. A. Stone, and J. Bibette, Nature 437, 862 (2005).