Gravity-induced dynamics of a squirmer microswimmer in wall proximity

Abstract

We perform hydrodynamic simulations using the method of multi-particle collision dynamics and a theoretical analysis to study a single squirmer microswimmer at high Péclet number, which moves in a low Reynolds number fluid and under gravity. The relevant parameters are the ratio $\alpha$ of swimming to bulk sedimentation velocity and the squirmer type $\beta$. The combination of self-propulsion, gravitational force, hydrodynamic interactions with the wall, and thermal noise leads to a surprisingly diverse behavior. At $\alpha >1$ we observe cruising states, while for $\alpha <1$ the squirmer resides close to the bottom wall with the motional state determined by stable fixed points in height and orientation. They strongly depend on the squirmer type $\beta$. While neutral squirmers permanently float above the wall with upright orientation, pullers float for $\alpha$ larger than a threshold value ${\alpha }_{\mathrm{th}}$ and are pinned to the wall below ${\alpha }_{\mathrm{th}}$. In contrast, pushers slide along the wall at lower heights, from which thermal orientational fluctuations drive them into a recurrent floating state with upright orientation, where they remain on the timescale of orientational persistence.

References in corpus (20)

• The hydrodynamics of swimming microorganisms
• Self-motile colloidal particles: from directed propulsion to random walk
• Motility-Induced Phase Separation
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Statistical Mechanics of Interacting Run-and-Tumble Bacteria
• Hydrodynamic attraction of swimming microorganisms by surfaces
• Designing phoretic micro- and nano-swimmers
• Hydrodynamics of self-propulsion near a boundary: predictions and accuracy of far-field approximations
• Emergent behavior in active colloids
• Topographical pathways guide chemical microswimmers
• Gravitaxis of asymmetric self-propelled colloidal particles
• Periodic and Quasiperiodic Motion of an Elongated Microswimmer in Poiseuille Flow
• Particle-Based Mesoscale Hydrodynamic Techniques
• Transport coefficients of off-lattice mesoscale-hydrodynamics simulation techniques
• Relevance of angular momentum conservation in mesoscale hydrodynamics simulations
• Exact solutions for hydrodynamic interactions of two squirming spheres
• Dynamic regimes of hydrodynamically coupled self-propelling particles
• Fission and fusion scenarios for magnetic microswimmer clusters
• Gravity-induced dynamics of a squirmer microswimmer in wall proximity
• Collective Sedimentation of Squirmers under Gravity

Cited by in corpus (23)

• The 2019 Motile Active Matter Roadmap
• Optimal steering of a smart active particle
• Gravity-induced dynamics of a squirmer microswimmer in wall proximity
• Spontaneously rotating clusters of active droplets
• Interactions in Active Colloids
• Swimming trajectories of a three-sphere microswimmer near a wall
• Dynamics of a chiral swimmer sedimenting on a flat plate
• Simulating squirmers with multiparticle collision dynamics
• State diagram of a three-sphere microswimmer in a channel
• Collective Dynamics in a Monolayer of Squirmers Confined to a Boundary by Gravity
• Towards an analytical description of active microswimmers in clean and in surfactant-covered drops
• Wall curvature driven dynamics of a microswimmer
• Rheotaxis of Active Droplets
• Multi-species dynamical density functional theory for microswimmers: derivation, orientational ordering, trapping potentials, and shear cells
• Frequency-dependent higher-order Stokes singularities near a planar elastic boundary: implications for the hydrodynamics of an active microswimmer near an elastic interface
• Creeping motion of a solid particle inside a spherical elastic cavity
• Microrobots from Toposelective Nanoparticle Attachment
• Simulation of microswimmer hydrodynamics with multiparticle collision dynamics
• Gravity induced formation of spinners and polar order of spherical microswimmers on a surface
• Langevin equations and a geometric integration scheme for the overdamped limit of rotational Brownian motion of axisymmetric particles
• Floor- or ceiling-sliding for chemically active, gyrotactic, sedimenting Janus particles
• Sedimentation and structure of squirmer suspensions under gravity
• Hydrodynamic interactions between a sedimenting squirmer and a planar wall