(Hosted by the Physics Department)

Wednesday, 03/10/2004
12:15 PM
Science Building, Room #418
(Physics Department)

Dr. Andy Lau
University of Pennsylvania
Department of Chemistry

"Microrheology and Stress Fluctuations in Living Cells "


One of the major challenge for modern biology is to understand how cells sense and produce force to respond to their environment in a directed manner. As a prerequisite, an accurate physical picture of the viscoelasticity and active behaviors of the cytoplasm requires powerful experimental techniques and theoretical modelling. Recently, microrheology has emerged as a new experimental tool to probe active cytoskeleton dynamics. In this talk, we provide a theoretical framework for interpreting passive microrheology experiments on non-equilibrium active systems such as living cells, demonstrate that two-point microrheology can be used to sensibly quantify the power spectrum of cytoskeletal stress fluctuations due to molecular motor activity in vivo, and propose a plausible microscopic model that explains the observed 1/f2 spectrum.

  • Ph.D. in Physics, October, 2000, University of California, Santa Barbara
  • Postdoctoral Fellow, College de France, Paris, France (November, 2000 - August, 2001)
  • Postdoctoral Fellow, University of Pennsylvania, Department of Physics and Astronomy, Soft Condensed Matter Group (September, 2001 - present). Research on depletion interaction mediated by semiflexible rods, phase behavior of nematic gels, microrheology of living cells, and correlation effects and dynamics in charged systems.