Lift at a soft wall

Heather Davies (1) , Delphine Débarre (1) , Claude Verdier (1) , Ralf P Richter (2) , Lionel Bureau (1)

1 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]
2 University of Leeds

We study experimentally the motion of non-deformable microbeads in a linear shear flow close to a wall bearing a thin and soft polymer layer. Combining microfluidics and 3D optical tracking, we observe that the steady-state bead/surface distance increases with the flow strength. Furthermore, we show that such lift is in quantitative agreement with theoretical predictions based on elastohy-drodynamics, which attribute the lift to flow-induced deformations of the layer. Thus, this study provides the first experimental evidence of " soft lubrication " at play at small scale, in a system relevant to e.g. the physics of blood microcirculation.

Domaines: Matière Molle [cond-mat.soft]

Heather Davies, Delphine Débarre, Claude Verdier, Ralf P Richter, Lionel Bureau. Lift at a soft wall. 2017. ⟨hal-01652253v1⟩