One-Bead Microrheology with Rotating Particles

Abstract

We lay the theoretical basis for one-bead microrheology with rotating particles, i.e, a method where colloids are used to probe the mechanical properties of viscoelastic media. Based on a two-fluid model, we calculate the compliance and discuss it for two cases. We first assume that the elastic and fluid component exhibit both stick boundary conditions at the particle surface. Then, the compliance fulfills a generalized Stokes law with a complex shear modulus whose validity is only limited by inertial effects, in contrast to translational motion. Secondly, we find that the validity of the Stokes regime is reduced when the elastic network is not coupled to the particle

arXiv comment7 pages, 5 figures, submitted to Europhys. Lett

References in corpus (6)

• Microscopic Viscoelasticity: Shear Moduli of Soft Materials Determined from Thermal Fluctuations
• Determining Microscopic Viscoelasticity in Flexible and Semiflexible Polymer Networks from Thermal Fluctuations
• Optical microrheology using rotating laser-trapped particles
• One- and two-particle microrheology
• Two-point microrheology and the electrostatic analogy
• Hydrodynamic coupling of two rotating spheres trapped in harmonic potentials

Cited by in corpus (4)

• Picolitre viscometry using optically rotated particles
• Rotating spherical particle in a continuous viscoelastic medium -- a microrheological example situation
• The role of boundaries for displacements and motion in two-dimensional fluid or elastic films and membranes
• Microrheology with rotational Brownian motion