Enhancement and Suppression of Active Particle Movement Due to Membrane Deformations

Abstract

Microswimmers and active colloids often move in confined systems, including those involving interfaces. Such interfaces, especially at the microscale, may deform in response to the stresses of the flow created by the active particle. We develop a theoretical framework to analyze the effect of a nearby membrane due to the motion of an active particle whose flow fields are generated by force-free singularities. We demonstrate our result on a particle represented by a combination of a force dipole and a source dipole, while the membrane resists deformation due to tension and bending rigidity. We find that the deformation either enhances or suppresses the motion of the active particle, depending on its orientation and the relative strengths between the fundamental singularities that describe its flow. Furthermore, the deformation can generate motion in new directions.