title: Soft swimming: exploiting deformable interfaces for low reynolds number locomotion.
abstract: Reciprocal movement cannot be used for locomotion at low Reynolds number in an infinite fluid or near a rigid surface. Here we show that this limitation is relaxed for a body performing reciprocal motions near a deformable interface. Using physical arguments and scaling relationships, we show that the nonlinearities arising from reciprocal flow-induced interfacial deformation rectify the periodic motion of the swimmer, leading to locomotion. Such a strategy can be used to move toward, away from, and parallel to any deformable interface as long as the length scales involved are smaller than intrinsic scales, which we identify. A macroscale experiment of flapping motion near a free surface illustrates this new result.
authors.affiliation: Hatsopoulos Microfluids Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Renaud
authors.initials: R
authors.lastname: Trouilloud
authors.forename: Tony S
authors.initials: TS
authors.lastname: Yu
authors.forename: A E
authors.initials: AE
authors.lastname: Hosoi
authors.forename: Eric
authors.initials: E
authors.lastname: Lauga