Flagellar swimmers oscillate between pusher- and puller-type swimming

摘要

Self-propulsion of cellular microswimmers generates flow signatures, commonlyclassified as pusher- and puller-type, which characterize hydrodynamicinteractions with other cells or boundaries. Using experimentally measured beatpatterns, we compute that flagellated alga and sperm oscillate between pusherand puller. Beyond a typical distance of 100 um from the swimmer, inertiaattenuates oscillatory micro-flows. We show that hydrodynamic interactionsbetween swimmers oscillate in time and are of similar magnitude as stochasticswimming fluctuations.