Flowing properties of quasi-2D emulsions in Couette geometry

We study the flow of dense emulsion in a quasi-two-dimensional Couette geometry. Our samples are oil-in-water emulsions confined between two close-spaced parallel plates, so that the droplets are deformed into pancake shapes.~By means of microscopy, we measure the droplet positions and their deformation,~which is related to the stress on the individual droplet. In this system without static coulomb friction, we observe a continuous transition from affine motion to topological rearrangements that span the whole system as the area fraction is increased. We compare our results to granular experiments and simulations.