From flagellar undulations to collective motion: predicting the dynamics of sperm suspensions
File(s)
Published version
Supporting information
Author(s)
Schoeller, Simon
Keaveny, EE
Type
Journal Article
Abstract
Swimming cells and microorganisms are as diverse in their collective dynamics as they are in their indi-
vidualshapesandpropulsionmechanisms. Evenforspermcells, whichhaveastereotypedshapeconsisting
of a cell body connected to a flexible flagellum, a wide range of collective dynamics is observed spanning
from the formation of tightly packed groups to the display of larger-scale, turbulence-like motion. Using a
detailed mathematical model that resolves flagellum dynamics, we perform simulations of sperm suspen-
sions containing up to 1000 cells and explore the connection between individual and collective dynamics.
We find that depending on the level of variation in individual dynamics from one swimmer to another,
the sperm exhibit either a strong tendency to aggregate, or the suspension exhibits large-scale swirling.
Hydrodynamic interactions govern the formation and evolution of both states. In addition, a quantitative
analysis of the states reveals that the flows generated at the time-scale of flagellum undulations contribute
significantly to the overall energy in the surrounding fluid, highlighting the importance of resolving these
flows.
vidualshapesandpropulsionmechanisms. Evenforspermcells, whichhaveastereotypedshapeconsisting
of a cell body connected to a flexible flagellum, a wide range of collective dynamics is observed spanning
from the formation of tightly packed groups to the display of larger-scale, turbulence-like motion. Using a
detailed mathematical model that resolves flagellum dynamics, we perform simulations of sperm suspen-
sions containing up to 1000 cells and explore the connection between individual and collective dynamics.
We find that depending on the level of variation in individual dynamics from one swimmer to another,
the sperm exhibit either a strong tendency to aggregate, or the suspension exhibits large-scale swirling.
Hydrodynamic interactions govern the formation and evolution of both states. In addition, a quantitative
analysis of the states reveals that the flows generated at the time-scale of flagellum undulations contribute
significantly to the overall energy in the surrounding fluid, highlighting the importance of resolving these
flows.
Date Issued
2018-03-31
Date Acceptance
2018-02-26
Citation
Journal of the Royal Society Interface, 2018, 15 (140), pp.1-10
ISSN
1742-5662
Publisher
Royal Society, The
Start Page
1
End Page
10
Journal / Book Title
Journal of the Royal Society Interface
Volume
15
Issue
140
Copyright Statement
© 2018 The Author(s). Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://royalsocietypublishing.org/doi/10.1098/rsif.2017.0834
Grant Number
EP/P013651/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
sperm locomotion
collective dynamics
active suspensions
fluid-structure interactions
FORCE-COUPLING METHOD
SLENDER-BODY THEORY
FLEXIBLE FIBERS
FLOWS
HYDRODYNAMICS
FILAMENTS
MOTILITY
PARTICLES
MODEL
active suspensions
collective dynamics
fluid–structure interactions
sperm locomotion
Animals
Computer Simulation
Flagella
Humans
Male
Models, Biological
Motion
Spermatozoa
Spermatozoa
Flagella
Animals
Humans
Motion
Models, Biological
Computer Simulation
Male
physics.flu-dyn
physics.flu-dyn
q-bio.CB
76Z10
General Science & Technology
Publication Status
Published
Article Number
20170834
Date Publish Online
2018-03-21