Department of Physics Papers

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Journal Article

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We present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than 4 times what steady swimming would require.


Suggested Citation:
Guasto, J., K.A. Johnson, and J.P. Gollub. (2010). Oscillatory Flows Induced by Mircroorganisms Swimming in Two Dimensions. Physical Review Letters. 105, 168102.

Copyright 2010 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. The following article appeared in Physical Review Letters and may be found at

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Date Posted: 27 October 2010