Particle Tracking Microrheology of Complex Fluids

T. G. Mason; K. Ganesan; J. H. van Zanten; D. Wirtz; S. C. Kuo

doi:10.1103/PhysRevLett.79.3282

Particle Tracking Microrheology of Complex Fluids

T. G. Mason, K. Ganesan, J. H. van Zanten, D. Wirtz, and S. C. Kuo

Phys. Rev. Lett. 79, 3282 – Published 27 October 1997

Abstract

We present a new method for measuring the linear viscoelastic shear moduli of complex fluids. Using photodiode detection of laser light scattered from a thermally excited colloidal probe sphere, we track its trajectory and extract the moduli using a frequency-dependent Stokes-Einstein equation. Spectra obtained for polyethylene oxide in water are in excellent agreement with those found mechanically and using diffusing wave spectroscopy. Since only minute sample volumes are required, this method is well suited for biomaterials of high purity, as we demonstrate with a concentrated DNA solution.

Received 21 January 1997

DOI:https://doi.org/10.1103/PhysRevLett.79.3282

Authors & Affiliations

T. G. Mason¹, K. Ganesan², J. H. van Zanten¹, D. Wirtz¹, and S. C. Kuo²

¹Department of Chemical Engineering, Johns Hopkins University, 221 Maryland Hall, 3400 North Charles Street, Baltimore, Maryland 21218
²Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore, Maryland 21205