Viscoelastic fluid response can increase the speed and efficiency of a free swimmer

Phys Rev Lett. 2010 Jan 22;104(3):038101. doi: 10.1103/PhysRevLett.104.038101. Epub 2010 Jan 19.


Microorganisms navigate through complex environments such as biofilms and mucosal tissues and tracts. To understand the effect of a complex medium upon their locomotion, we investigate numerically the effect of fluid viscoelasticity on the dynamics of an undulating swimming sheet. First, we recover recent small-amplitude results for infinite sheets that suggest that viscoelasticity impedes locomotion. We find the opposite result when simulating free swimmers with large tail undulations, with both velocity and mechanical efficiency peaking for Deborah numbers near one. We associate this with regions of highly stressed fluid aft of the undulating tail.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Body Fluids / chemistry*
  • Elasticity*
  • Female
  • Kinetics
  • Male
  • Models, Biological
  • Movement / physiology*
  • Rheology
  • Spermatozoa / physiology*
  • Viscosity