Description: Sperm motility in modulated microchannels

This title appears in the Scientific Report : 2019

Sperm motility in modulated microchannels

Sperm cells swim through the fluid by a periodic wave-like beating of their flagellum. At low Reynolds numbers and in confinement, the directed motion of sperm and other microswimmers is strongly influenced by steric and hydrodynamic wall interactions. We model sperm motil...

Personal Name(s):	Rode, Sebastian (Corresponding author)
	Elgeti, Jens / Gompper, Gerhard
Contributing Institute:	Theorie der Weichen Materie und Biophysik; ICS-2 JARA - HPC; JARA-HPC
Published in:	New journal of physics, 21 (2019) S. 013016
Imprint:	[London] IOP73379 2019
DOI:	10.1088/1367-2630/aaf544
Document Type:	Journal Article
Research Program:	Hydrodynamics of Active Biological Systems Physical Basis of Diseases
Link:	Get full text Get full text OpenAccess OpenAccess
	Publikationsportal JuSER

Please use the identifier: http://hdl.handle.net/2128/21500 in citations.
Please use the identifier: http://dx.doi.org/10.1088/1367-2630/aaf544 in citations.

Sperm cells swim through the fluid by a periodic wave-like beating of their flagellum. At low Reynolds numbers and in confinement, the directed motion of sperm and other microswimmers is strongly influenced by steric and hydrodynamic wall interactions. We model sperm motility in mesoscale hydrodynamics simulations by imposing a planar traveling bending wave along the flagellum. Sperm are simulated swimming in curved, straight, shallow and zigzag-shaped microchannels. Changes in the sidewall modulations and the imposed beat pattern allow the identification of a strong dependence of the surface attraction on the beat-shape envelope of the sperm cell. For swimming in zigzag microchannels, the deflection-angle distribution at sharp corners is calculated and found to be in good agreement with recent microfluidic experiments. The simulations reveal a strong dependence of the deflection angle on the orientation of the beat plane with respect to the channel sidewall, and thus deepen the understanding of sperm navigation under strong confinement. Detachment of sperm, while swimming along curved walls, is dominated by the change of beat- plane orientation. Therefore, either the emergence of a nonplanar component of the flagellar beat with increasing wavelength or the strong confinement in shallow channels drastically increases wall attraction. Our simulation results reveal a consistent picture of passive sperm guidance that is dominated by the steric interactions of the beat pattern with the nearby surfaces.