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Fluid Dynamics Seminar


Monday, Apr. 23, 2012, 4:00 PM
Cullimore, Room 611
New Jersey Institute of Technology

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Experiments and Theory of Undulatory Locomotion in Structured Media


Trushant Majmudar

 

Courant Institute, New York University



Abstract

 

To thrive parasites, worms, and spermatozoa must successfully negotiate complex, fluid-filled environments. To understand successful strategies of navigation requires quantifying the roles of sensing and locomotory mechanics. We experimentally investigate swimming of the nematode the C. elegans through a lattice of micro-pillars and conduct numerical simulations based on a mechanical model of the worm that incorporates hydrodynamic and contact interactions with the lattice. We show that the nematode's path, speed, and gait are significantly altered by the presence of the obstacles and depend strongly on lattice spacing. Our purely mechanical model captures these changes qualitatively and quantitatively. Using the model, we demonstrate that purely mechanical interactions between the swimmer and obstacles can produce complex trajectories, gait changes, and velocity fluctuations, yielding some of the life-like dynamics exhibited by the real nematode. Our results show that mechanics, rather than biological sensing and behavior, can explain some (though not all) of the observed changes in the worm's locomotory dynamics.