Self-buckling and self-writhing of semi-flexible microorganisms
arXiv:2211.04381 · doi:10.1039/d3sm00572k
Abstract
The twisting and writhing of a cell body and associated mechanical stresses is an underappreciated constraint on microbial self-propulsion. Multi-flagellated bacteria can even buckle and writhe under their own activity as they swim through a viscous fluid. New equilibrium configurations and steady-state dynamics then emerge which depend on the organism's mechanical properties and on the oriented distribution of flagella along its surface. Modeling the cell body as a semi-flexible Kirchhoff rod and coupling the mechanics to a dynamically evolving flagellar orientation field, we derive the Euler-Poincar{é} equations governing dynamics of the system, and rationalize experimental observations of buckling and writhing of elongated swarmer cells of the bacterium {\it Proteus mirabilis}. A sequence of bifurcations is identified as the body is made more compliant, due to both buckling and torsional instabilities. These studies highlight a practical requirement for the stiffness of bacteria below which self-buckling occurs and cell motility becomes ineffective.
arXiv comment7 pages, 3 figures
References in corpus (24)
- The hydrodynamics of swimming microorganisms
- The Magnus expansion and some of its applications
- Self-propelled Worm-like Filaments: Spontaneous Spiral Formation, Structure, and Dynamics
- Trapping and Wiggling: Elastohydrodynamics of Driven Microfilaments
- Dynamics of filaments and membranes in a viscous fluid
- Optimal Swimming at low Reynolds numbers
- Twirling and Whirling: Viscous Dynamics of Rotating Elastica
- The Viscous Nonlinear Dynamics of Twist and Writhe
- The optimal elastic flagellum
- Morphological transitions of elastic filaments in shear flow
- The sedimentation of flexible filaments
- Propulsion and instability of a flexible helical rod rotating in a viscous fluid
- Autonomous Motility of Active Filaments due to Spontaneous Flow-Symmetry Breaking
- Flexible filaments buckle into helicoidal shapes in strong compressional flows
- Sustained unidirectional rotation of a self-organized DNA rotor on a nanopore
- Slender-ribbon theory
- Impacts of multiflagellarity on stability and speed of bacterial locomotion
- Lagrange-Poincare field equations
- Deformation and shape of flexible, microscale helices in viscous flow
- Importance and effectiveness of representing the shapes of Cosserat rods and framed curves as paths in the special Euclidean algebra
- Eulerian simulation of complex suspensions and biolocomotion in three dimensions
- Slender body theories for rotating filaments
- A hydrodynamic slender-body theory for local rotation at zero Reynolds number
- Helical trajectories of swimming cells with a flexible flagellar hook