Undulatory swimming in viscoelastic fluids.
1Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Physical Review Letters
|June 15, 2011
Summary
Fluid elasticity significantly slows the swimming speed of the nematode Caenorhabditis elegans, with propulsion decreasing as elastic stresses increase. This finding impacts understanding of locomotion in complex fluids.
Area of Science:
- Biophysics
- Fluid Dynamics
- Nematology
Background:
- The nematode Caenorhabditis elegans is a model organism for studying biological locomotion.
- Understanding how organisms move in complex, non-Newtonian fluids is crucial for various biological and engineering applications.
Purpose of the Study:
- To experimentally investigate the impact of fluid elasticity on the swimming behavior of Caenorhabditis elegans.
- To quantify the relationship between fluid viscoelasticity and nematode propulsion efficiency.
Main Methods:
- Tracking the swimming motion of Caenorhabditis elegans.
- Measuring velocity fields around the moving nematode.
- Analyzing the effects of varying fluid elastic properties.
Main Results:
- Fluid elasticity was found to hinder the self-propulsion of Caenorhabditis elegans.
- Propulsion speed decreased by up to 35% in elastic fluids compared to Newtonian fluids.
- Self-propulsion diminished with increasing elastic stress, linked to molecular stretching near flow singularities.
Conclusions:
- Elasticity in fluids negatively affects nematode swimming performance.
- The findings provide insights into the biomechanics of locomotion in viscoelastic media.
- This research highlights the importance of fluid properties in biological movement.
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