Fluid-structure interactions in a soft-walled Hele-Shaw cell*

The interaction of viscous and interfacial flows with soft materials has recently attracted substantial interest from a variety of different perspectives. Here, we study these interactions in the context of a model problem: Flow in a deformable Hele-Shaw cell, where one wall is rigid and the other is soft. Combining experiments with mathematical modelling, we consider the coupling of flow and deformation as viscous fluid is injected into an initially empty cell. We then discuss the implications of these results for hydrodynamic instabilities such as viscous fingering.