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AKB: Biologische Physik

AKB 12: Soft-Matter Nanofluidic Devices

AKB 12.7: Vortrag

Dienstag, 28. März 2006, 15:45–16:00, ZEU 255

Hydrodynamics of Sperm Motion near Hard Walls — •Jens Elgeti and Gerhard Gompper — Forschungszentrum Jülich, Institut für Festkörperforschung, 52425 Jülich

Sperm cells are propelled in a fluid by an active, snake-like motion of its tail, the flagellum. It is already known for some time experimentally that cells accumulate at a wall, swimming always in clockwise circles.

We investigate the sperm motion in a film geometry theoretically. The sperm tail is modelled as a semi-flexible polymer, which is subjected to a sinusoidal bending force. The sperm head is modeled as a sphere, asymmetrically displaced from the beat plane of the tail. Hydrodynamic interactions, which are responsible for the directed motion of the cell, are taken into account by a particle-based, mesoscopic simulation technique (multi-particle collision dynamics).

We show that this highly simplified model captures the basic features of cell motion described above. This shows that hydrodynamic interactions are responsible for the effective attraction to a wall.

Tuning the asymmetry, we find three different types of motion, which are characterized by different radii of curvature, different distance distributions from the wall, and different angles between the beat plane and the wall. Finally, we compare our results with experimental data.