Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version



Keim, N. C., Garcia, M., & Arratia, P. E. (2012). Fluid elasticity can enable propulsion at low Reynolds number. Physics of Fluids, 24(8), 081703. doi: 10.1063/1.4746792

Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.


Conventionally, a microscopic particle that performs a reciprocal stroke cannot move through its environment. This is because at small scales, the response of simple Newtonian fluids is purely viscous and flows are time-reversible. We show that by contrast, fluid elasticity enables propulsion by reciprocal forcing that is otherwise impossible. We present experiments on rigid objects actuated reciprocally in viscous fluids, demonstrating for the first time a purely elastic propulsion set by the object’s shape and boundary conditions. We describe two different artificial “swimmers” that experimentally realize this principle.



Date Posted: 27 February 2013

This document has been peer reviewed.