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arXiv · 1601.03063

Self-sustained lift and low friction via soft lubrication

Baudouin Saintyves·Théo Jules·Thomas Salez·L. Mahadevan
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Abstract

Relative motion between soft wet solids arises in a number of applications in natural and artificial settings, and invariably couples elastic deformation and fluid flow. We explore this in a minimal setting by considering a fluid-immersed negatively-buoyant cylinder moving along a soft inclined wall. Our experiments show that there is an emergent robust steady-state sliding regime of the cylinder with an effective friction that is significantly reduced relative to that of rigid fluid-lubricated contacts. A simple scaling approach that couples the cylinder-induced flow to substrate deformation allows us to explain the emergence of an elastohydrodynamic lift that underlies the self-sustained lubricated motion of the cylinder, consistent with recent theoretical predictions. Our results suggest an explanation for a range of effects such as reduced wear in animal joints and long-runout landslides, and can be couched as a design principle for low-friction interfaces.

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Baudouin Saintyves, Théo Jules, Thomas Salez, L. Mahadevan. 2016-01-12. Self-sustained lift and low friction via soft lubrication. https://doi.org/10.1073/pnas.1525462113

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