Microswimming in viscoelastic fluids

Abstract

The locomotion of microorganisms and spermatozoa in complex viscoelastic fluids is of critical importance in many biological processes such as fertilization, infection, and biofilm formation. Depending on their propulsion mechanisms, microswimmers display various responses to a complex fluid environment: increasing or decreasing their swimming speed and efficiency, modifying their propulsion kinematics and swimming gaits, and experiencing different hydrodynamic interactions with their surroundings. In this article, we review the fundamental physics of locomotion of biological and synthetic microswimmers in complex viscoelastic fluids. Starting from a continuum framework, we describe the main theoretical approaches developed to model microswimming in viscoelastic fluids, which typically rely on asymptotically small dimensionless parameters. We then summarise recent progress on the mobility of single cells propelled by cilia, waving flagella and rotating helical flagella in unbounded viscoelastic fluids. We next briefly discuss the impact of other physical factors, including the micro-scale heterogeneity of complex biological fluids, the role of Brownian fluctuations of the microswimmers, the effect of polymer entanglement and the influence of shear-thinning viscosity. In particular, for solutions of long polymer chains whose sizes are comparable to the radius of flagella, continuum models cannot be used and instead Brownian Dynamics for the polymers can predict the swimming dynamics. Finally, we discuss the effect of viscoelasticity on the dynamics of microswimmers in the presence of surfaces or external flows and its impact on collective cellular behavior.

References in corpus (45)

• Active Particles in Complex and Crowded Environments
• The hydrodynamics of swimming microorganisms
• Swimming in circles: Motion of bacteria near solid boundaries
• Hydrodynamic attraction of swimming microorganisms by surfaces
• Elastic turbulence in a polymer solution flow
• Fluid dynamics and noise in bacterial cell-cell and cell-surface scattering
• Collective Motion of Vibrated Polar Disks
• Bacterial hydrodynamics
• Living Liquid Crystals
• Efficient Mixing at low Reynolds numbers using polymer additives
• Propulsion in a viscoelastic fluid
• Undulatory swimming in viscoelastic fluids
• Flagellated bacterial motility in polymer solutions
• Dynamics of self-propelled Janus particles in viscoelastic fluids
• Locomotion of helical bodies in viscoelastic fluids: enhanced swimming at large helical amplitudes
• Swimming speeds of filaments in nonlinearly viscoelastic fluids
• Enhanced low-Reynolds-number propulsion in heterogeneous viscous environments
• Theory of swimming filaments in viscoelastic media
• Enhanced bacterial swimming speeds in macromolecular polymer solutions
• Hydrodynamic phase-locking of swimming microorganisms
• Squirmers with swirl -- a model for $Volvox$ swimming
• Memory-induced transition from a persistent random walk to circular motion for achiral microswimmers
• Modeling a spheroidal microswimmer and cooperative swimming in thin films
• Fluid elasticity increases the locomotion of flexible swimmers
• Upstream swimming in microbiological flows
• Beating patterns of filaments in viscoelastic fluids
• Locomotion by tangential deformation in a polymeric fluid
• Enhanced active swimming in viscoelastic fluids
• Physics of Rheologically-Enhanced Propulsion: Different Strokes in Generalized Stokes
• Fluid Elasticity Can Enable Propulsion at Low Reynolds Number
• Flapping motion and force generation in a viscoelastic fluid
• Hydrodynamic interaction of a self-propelling particle with a wall: Comparison between an active Janus particle and a squirmer model
• Enhanced rotational motion of spherical squirmer in polymer solutions
• An active particle in a complex fluid
• Undulatory swimming in fluids with polymer networks
• Pumping by flapping in a viscoelastic fluid
• Active Viscoelastic Matter: from Bacterial Drag Reduction to Turbulent Solids
• The effect of gait on swimming in viscoelastic fluids
• An empirical resistive-force theory for slender biological filaments in shear-thinning fluids
• The role of body flexibility in stroke enhancements for finite-length undulatory swimmers in viscoelastic fluids
• The mechanism of propulsion of a model microswimmer in a viscoelastic fluid next to a solid boundary
• Numerical investigation of elasto-inertial particle focusing patterns in viscoelastic microfluidic devices
• Viscoelastic and elastomeric active matter: Linear instability and nonlinear dynamics
• Biopolymer dynamics driven by helical flagella
• A note on higher order perturbative corrections to squirming speed in weakly viscoelastic fluids