Self-Sustained Lift and Low Friction via Soft Lubrication

May 12, 2016

Fig. 1: Experimental setup and laser profilometry

Contacting solids that move relative to each other in a fluid environment abound in many settings such as soft contact lenses in eyes, animal joints, and bearings in rotating machinery. Motion is inevitably accompanied by flow and deformation, and raises the question of how these correlate with friction at the interface. Prof. L. Mahadevan and SEAS colleagues Baudouin Saintyvesa, Theo Julesa, and Thomas Saleza explored this relative motion in a minimal experimental setting, associated with how a cylinder slides and rolls along a soft inclined plane. This setting allowed the scientists to see the induction of a self-sustained lift that reduces the friction by nearly an order of magnitude. Their results, which will be published in PNAS, 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.

See B. Saintyves, T. Jules, T. Salez, L. Mahadevan, "Self-sustained lift and low friction via soft lubrication," Proc. Natl. Acad. Sci. (May 9, 2016) doi:10.1073/pnas.1525462113.)