No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
The full text of this article is not currently available.
Physics of rheologically enhanced propulsion: Different strokes in generalized Stokes
13. L. Hall-Stoodley, J. W. Costerton, and P. Stoodley, “Bacterial biofilms: From the natural environment to infectious diseases,” Nat. Rev. Microbiol. 2(2), 95–108 (2004).
14. N. Verstraeten, K. Braeken, B. Debkumari, M. Fauvart, J. Fransaer, J. Vermant, and J. Michiels, “Living on a surface: Swarming and biofilm formation,” Trends Microbiol. 16(10), 496–506 (2008).
21. H. C. Fu, C. W. Wolgemuth, and T. R. Powers, “Swimming speeds of filaments in nonlinearly viscoelastic fluids,” Phys. Fluids 21, 033102–1033102–10 (2009).
22. L. Zhu, E. Lauga, and L. Brandt, “Self-propulsion in viscoelastic fluids: Pushers vs. pullers,” Phys. Fluids 24(5), 051902–1051902–17 (2012).
24. S. K. Lai, D. E. O'Hanlon, S. Harrold, S. T. Man, Y. Y. Wang, R. Cone, and J. Hanes, “Rapid transport of large polymeric nanoparticles in fresh undiluted human mucus,” Proc. Natl. Acad. Sci. U.S.A. 104(5), 1482 (2007).
25. D. F. Katz and S. A. Berger, “Flagellar propulsion of human sperm in cervical mucus,” Biorheology 17(1–2), 169 (1980).
26. N. J. Balmforth, D. Coombs, and S. Pachmann, “Microelastohydrodynamics of swimming organisms near solid boundaries in complex fluids,” Q. J. Mech. Appl. Math. 63(3), 267–294 (2010).
28. T. D. Montenegro-Johnson, A. A. Smith, D. J. Smith, D. Loghin, and J. R. Blake, “Modelling the fluid mechanics of cilia and flagella in reproduction and development,” Eur. Phys. J. E 35(10), 111 (2012).
29. R. N. Mills and D. F. Katz, “A flat capillary tube system for assessment of sperm movement in cervical mucus,” Fertil. Steril. 29, 43–47 (1978).
30. D. F. Katz, J. W. Overstreet, and F. W. Hanson, “A new quantitative test for sperm penetration into cervical mucus,” Fertil. Steril. 33, 179 (1980).
31. D. J. Smith, E. A. Gaffney, H. Gadêlha, N. Kapur, and J. C. Kirkman-Brown, “Bend propagation in the flagella of migrating human sperm, and its modulation by viscosity,” Cell Motil. Cytoskeleton 66, 220–236 (2009).
32. N. Phan-Thien, Understanding Viscoelasticity: Basics of Rheology (Springer Verlag, Berlin, 2002).
37. G. K. Batchelor, An Introduction to Fluid Mechanics (Cambridge University Press, New York, 1967).
39. D. Crowdy, S. Lee, O. Samson, E. Lauga, and A. E. Hosoi, “A two-dimensional model of low-Reynolds number swimming beneath a free surface,” J. Fluid Mech. 681(1), 24–47 (2011).
44. S. Childress, Mechanics of Swimming and Flying (Cambridge University Press, Cambridge, 1981).
51. D. J. Smith, “A boundary element regularized Stokeslet method applied to cilia-and flagella-driven flow,” Proc. R. Soc. London, Ser. A 465(2112), 3605–3626 (2009).
Article metrics loading...
Shear-thinning is an important rheological property of many biological fluids, such as mucus, whereby the apparent viscosity of the fluid decreases with shear. Certain microscopic swimmers have been shown to progress more rapidly through shear-thinning fluids, but is this behavior generic to all microscopic swimmers, and what are the physics through which shear-thinning rheology affects a swimmer's propulsion? We examine swimmers employing prescribed stroke kinematics in two-dimensional, inertialess Carreau fluid: shear-thinning “generalized Stokes” flow. Swimmers are modeled, using the method of femlets, by a set of immersed, regularized forces. The equations governing the fluid dynamics are then discretized over a body-fitted mesh and solved with the finite element method. We analyze the locomotion of three distinct classes of microswimmer: (1) conceptual swimmers comprising sliding spheres employing both one- and two-dimensional strokes, (2) slip-velocity envelope models of ciliates commonly referred to as “squirmers,” and (3) monoflagellate pushers, such as sperm. We find that morphologically identical swimmers with different strokes may swim either faster or slower in shear-thinning fluids than in Newtonian fluids. We explain this kinematic sensitivity by considering differences in the viscosity of the fluid surrounding propulsive and payload elements of the swimmer, and using this insight suggest two reciprocal sliding sphere swimmers which violate Purcell's Scallop theorem in shear-thinning fluids. We also show that an increased flow decay rate arising from shear-thinning rheology is associated with a reduction in the swimming speed of slip-velocity squirmers. For sperm-like swimmers, a gradient of thick to thin fluid along the flagellum alters the force it exerts upon the fluid, flattening trajectories and increasing instantaneous swimming speed.
Full text loading...
Most read this month