title: Characteristic spatial scale of vesicle pair interactions in a plane linear flow.
abstract: We report the experimental studies on interaction of two vesicles trapped in a microfluidic four-roll mill, where a plane linear flow is realized. We found that the dynamics of a vesicle in tank-treading motion is significantly altered by the presence of another vesicle at separation distances up to 3.2-3.7 times of the vesicle effective radius. This result is supported by measurement of a single vesicle back-reaction on the velocity field. Thus the experiment provides the upper bound for the volume fraction φ = 0.08-0.13 of noninteracting vesicle suspensions.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Levant
authors.forename: Julien
authors.initials: J
authors.lastname: Deschamps
authors.forename: Eldad
authors.initials: E
authors.lastname: Afik
authors.forename: Victor
authors.initials: V
authors.lastname: Steinberg