Hydrodynamic lift on bound vesicles

Bound vesicles subject to lateral farces such as arising from shear Row are investigated theoretically by combining a lubrication analysis of the boun d part with a scaling approach to the global motion. A minor inclination of the bound part leads to significant lift due to the additive effects of la teral and tank-treading motions. With increasing shear rate, the vesicle un binds from the substrate at a critical value. Estimates are in agreement wi th recent experimental data.