Skip to main content
banner image
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.
1.Almog, Y. , and H. Brenner, “Non-continuum anomalies in the apparent viscosity experienced by a test sphere moving through an otherwise quiescent suspension,” Phys. Fluids1070-6631 9, 1622 (1997).
2.Banchio, A. J. , G. Nagele, and J. Bergenholtz, “Viscoelasticity and generalized Stokes-Einstein relations of colloidal dispersions,” J. Chem. Phys.0021-9606 111, 87218740 (1999).
3.Bergenholtz, J. , J. F. Brady, and M. Vicic, “The non-Newtonian rheology of dilute colloidal suspensions,” J. Fluid Mech.0022-1120 456, 239275 (2002).
4.Brady, J. F. , “Computer simulation of viscous suspensions,” Chem. Eng. Sci.0009-2509 56, 29212926 (2001).
5.Campbell, A. I. , and P. Bartlett, “Fluorescent hard-sphere polymer colloids for confocal microscopy,” J. Colloid Interface Sci.0021-9797 256, 325330 (2002).
6.Chae, B. S. , and E. M. Furst, “Probe surface chemistry dependence and local polymer network structure in F-actin microrheology,” Langmuir0743-7463 21, 30843089 (2005).
7.Chen, D. T. , E. R. Weeks, J. C. Crocker, M. F. Islam, R. Verma, J. Gruber, A. J. Levine, T. C. Lubensky, and A. G. Yodh, “Rheological microscopy: Local mechanical properties from microrheology,” Phys. Rev. Lett.0031-9007 90, 108301 (2003).
8.Crocker, J. C. , and D. G. Grier, “Methods of digital video microscopy for colloidal studies,” J. Colloid Interface Sci.0021-9797 179, 298310 (1996).
9.Foss, D. R. , and J. F. Brady, “Structure, diffusion and rheology of Brownian suspensions by stokesian dynamics simulation,” J. Fluid Mech.0022-1120 407, 167200 (2000).
10.Gardel, M. , M. Valentine, J. Crocker, A. Bausch, and D. Weitz, “Microrheology of entangled F-actin solutions,” Phys. Rev. Lett.0031-9007 91, 158302 (2003).
11.Habdas, P. , D. Scharr, A. C. Levitt, and E. R. Weeks, “Forced motion of a probe particle near the colloidal glass transition,” Europhys. Lett.0295-5075 67, 477483 (2004).
12.Happel, J. , and H. Brenner, Low Reynolds Number Hydrodynamics (Prentice-Hall, Englewood Cliffs, NJ, 1965).
13.Horn, F. M. , W. Richtering, J. Bergenholtz, N. Willenbacher, and N. J. Wagner, “Hydrodynamic and colloidal interactions in concentrated charge-stabilized polymer dispersions,” J. Colloid Interface Sci.0021-9797 225, 166178 (2000).
31.Khair, A. S. , and J. F. Brady, J. Rheol.0148-6055 49, 14491481 (2005).
14.Larson, R. G. , The Structure and Rheology of Complex Fluids (Oxford University Press, New York, 1999).
15.Le Goff, L. , F. Amblard, and E. M. Furst, “Motor-driven dynamics in actin-myosin networks,” Phys. Rev. Lett.0031-9007 88, 018101 (2002).
16.Mason, T. G. , “Estimating the viscoelastic moduli of complex fluids using the generalized Stokes-Einstein equation,” Rheol. Acta0035-4511 39, 371378 (2000).
17.Mason, T. G. , T. Gisler, K. Kroy, E. Frey, and D. A. Weitz, “Rheology of F-actin solutions determined from thermally driven tracer motion,” J. Rheol.0148-6055 44, 917928 (2000).
18.Mason, T. G. , and D. A. Weitz, “Optical measurements of frequency-dependent linear viscoelastic moduli of complex fluids,” Phys. Rev. Lett.0031-9007 74, 12501253 (1995).
19.Pantina, J. P. , and E. M. Furst, “Directed assembly and rupture mechanics of colloidal aggregates,” Langmuir0743-7463 20, 39403946 (2004).
20.Papir, Y. S. , and I. M. Krieger, “Rheological studies on dispersions of uniform colloidal spheres. 2. Dispersions in nonaqueous media,” J. Colloid Interface Sci.0021-9797 34, 126130 (1970).
21.Rasband, W. S. , ImageJ (U.S. National Institutes of Health, Bethesda, MD 1997–2005);
22.Russel, W. B. , D. A. Saville, and W. R. Schowalter, Colloidal Dispersions (Cambridge University Press, Cambridge, 1989).
23.Schnurr, B. , F. Gittes, F. MacKintosh, and C. Schmidt, “Determining microscopic viscoelasticity in flexible and semiflexible polymer networks from thermal fluctuations,” Macromolecules0024-9297 30, 77817792 (1997).
24.Simmons, R. M. , J. T. Finer, S. Chu, and J. A. Spudich, “Quantitative measurements of force and displacement using an optical trap,” Biophys. J.0006-3495 70, 18131822 (1996).
25.Squires, T. M. , and J. F. Brady, “A simple paradigm for active and nonlinear microrheology,” Phys. Fluids1070-6631 17, 073101 (2005).
26.Valentine, M. , P. Kaplan, D. Thota, J. Crocker, T. Gisler, R. Prud’homme, M. Beck, and D. Weitz, “Investigating the microenvironments of inhomogeneous soft materials with multiple particle tracking,” Phys. Rev. E1063-651X 64, 061506 (2001).
27.Valentine, M. T. , L. E. Dewalt, and H. D. Ou-Yang, “Forces on a colloidal particle in a polymer solution: a study using optical tweezers,” J. Phys.: Condens. Matter0953-8984 8, 94779482 (1996).
28.Velegol, D. , and F. Lanni, “Cell traction forces on soft biomaterials. I. Microrheology of type I collagen gels,” Biophys. J.0006-3495 81, 17861792 (2001).
29.Yamada, S. , D. Wirtz, and S. C. Kuo, “Mechanics of living cells measured by laser tracking microrhology,” Biophys. J.0006-3495 78, 17361747 (2000).
30.Ziemann, F. , J. Radler, and E. Sackmann, “Local measurements of viscoelastic moduli of entangled actin networks using an oscillating magnetic bead micro-rheometer,” Biophys. J.0006-3495 66, 22102216 (1994).

Data & Media loading...


Article metrics loading...



The microrheology of a colloidalsuspension is measured using laser tweezers. Suspensions of refractive index-matched fluorinated ethylene propylene (FEP) particles are seeded with index-mismatched polystyrene or silica probe particles. Laser trapped probes are then subjected to steady uniform flows, enabling measurements of the suspension microviscosity as a function of FEP volume fraction and flow velocity. The microrheology results agree with bulk rheology, and both exhibit the same volume fraction dependence of the Krieger-Dougherty relationship for hard spheres. As volume fraction increases, the microrheology more closely agrees with the infinite shear bulk viscosity. In this regime, measurements using small probes exhibit additional shear thinning. Using confocal microscopy and fluorescent poly(methylmethacrylate) dispersions, we demonstrate that the nonlinear microrheology is consistent with the development of an anisotropic nonequilibrium pair distribution function between the probe and bath particles, with a denser region at the leading surface of the probe and a wake trailing it. The nonlinear response and underlying microstructure are in qualitative agreement with recent theory [T. M. Squires and J. F. Brady, Phys. Fluids17, 073101 (2005)].


Full text loading...


Access Key

  • FFree Content
  • OAOpen Access Content
  • SSubscribed Content
  • TFree Trial Content
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd