Dynamics and interactions of active rotors

Abstract

We consider a simple model of an internally driven self-rotating object; a rotor, confined to two dimensions by a thin film of low Reynolds number fluid. We undertake a detailed study of the hydrodynamic interactions between a pair of rotors and find that their effect on the resulting dynamics is a combination of fast and slow motions. We analyse the slow dynamics using an averaging procedure to take account of the fast degrees of freedom. Analytical results are compared with numerical simulations. Hydrodynamic interactions mean that while isolated rotors do not translate, bringing together a pair of rotors leads to motion of their centres. Two rotors spinning in the same sense rotate with an approximately constant angular velocity around each other, while two rotors of opposite sense, both translate with the same constant velocity, which depends on the separation of the pair. As a result a pair of counter-rotating rotors are a promising model for controlled self-propulsion.

6 pages, 6 figures

References in corpus (8)

• Collective motion of self-propelled particles interacting without cohesion
• Analytic results for the three-sphere swimmer at low Reynolds number
• Synchronization and Collective Dynamics in a Carpet of Microfluidic Rotors
• A mean-field theory for self-propelled particles interacting by velocity alignment mechanisms
• Corrections to the Saffman-Delbruck mobility for membrane bound proteins
• No many-scallop theorem: Collective locomotion of reciprocal swimmers
• Hydrodynamics of isotropic and liquid crystalline active polymer solutions
• Two-sphere low Reynold's propeller

Cited by in corpus (20)

• Tuned, driven, and active soft matter
• Targeted Assembly and Synchronization of Self-Spinning Microgears
• Hydrodynamic suppression of phase separation in active suspensions
• Collective dynamics in a binary mixture of hydrodynamically coupled micro-rotors
• Colloidal Microworms Propelling via a Cooperative Hydrodynamic Conveyor Belt
• Purely hydrodynamic ordering of rotating disks at a finite Reynolds number
• Cooperative Self-Propulsion of Active and Passive Rotors
• Diffusion of active chiral particles
• Fission and fusion scenarios for magnetic microswimmer clusters
• Hydrodynamic assembly of active colloids: chiral spinners and dynamic crystals
• Periodic and chaotic orbits of plane-confined micro-rotors in creeping flows
• Elasticity Induced Force Reversal Between Active Spinning Particles in Dense Passive Media
• Getting drowned in a swirl: deformable bead-spring model microswimmers in external flow fields
• Synchronisation and liquid crystalline order in soft active fluids
• Dynamics of groups of magnetically driven artificial microswimmers
• Hydrodynamically-bound states of a pair of microrollers: a dynamical system insight
• Polarisation of cells and soft objects driven by mechanical interactions: Consequences for migration and chemotaxis
• Dumbbell micro-robot driven by flow oscillations
• Anomalous grain dynamics and grain locomotion of odd crystals
• Vortex Dynamics in Tubular Fluid Membranes