Mechanical response of a thick poroelastic gel in contactless colloidal-probe rheology

When a rigid object approaches soft material in viscous fluid, hydrodynamic stresses arise the lubricated contact region and deform material. The elastic deformation modifies turn flow, hence generating soft-lubrication coupling. Moreover, elastomers gels are often porous. These materials may be filled with solvent or uncrosslinked polymer chains, might permeable to surrounding which complexifies further description. Here, we derive point-force response of semi-infinite poroelastic substrate. Then, use this fundamental solution order address specific lubrication coupling associated contactless colloidal-probe methods. In particular, conservative dissipative components force oscillating vertical motion sphere close Our results relevant for dynamic surface apparatus atomic microscopy experiments on soft, living and/or fragile materials, such as swollen hydrogels biological membranes.