  The motion of an object within a viscous fluid and in the vicinity of a soft
surface induces a hydrodynamic stress field that deforms the latter, thus
modifying the boundary conditions of the flow. This results in
elastohydrodynamic (EHD) interactions experienced by the particle. Here, we
derive a soft-lubrication model, in order to compute all the forces and torque
applied on a rigid sphere that is free to translate and rotate near an elastic
wall. We focus on the limit of small deformations of the surface with respect
to the fluid-gap thickness, and perform a perturbation analysis in
dimensionless compliance. The response is computed in the framework of linear
elasticity, for planar elastic substrates in the limiting cases of thick and
thin layers. The EHD forces are also obtained analytically using the Lorentz
reciprocal theorem.
