Levich Institute Seminar Announcement, 05/10/2016
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Professor Victor Steinberg
Weizmann Institute of Science
Department of Physics of Complex Fluids
"Role of Thermal Noise in Vesicle Dynamics in a General Linear Flow"
Understanding the dynamics of a single vesicle in the context of micro-macro interrelations vesicle suspensions poses a challenge to researchers in a variety of fields, from fundamental physics to bio-medical engineering. Theoretical/numerical models of vesicle dynamics usually overlook thermal noise seemingly negligible due to the large ratio ?/kBT~25-50, where ? is the bending energy. However an experimental observation of an intermediate trembling (TR) state, which is a key state to understand vesicle dynamics, reveals that its dynamics is very different from the predictions of deterministic models. A detailed experimental investigation of single vesicle dynamics in the TR state discovers a new mechanism of amplification of thermal noise by vesicle dynamics that is responsible for many characteristic features such as the appearance of symmetry-breaking of even modes in vesicle shape perturbations (M.Levant and V.Steinberg, Phys. Rev. Lett. 109, 268103 (2012), contrary to theoretical predictions and numerical simulations neglecting thermal noise. However, these results are reproduced in 3D simulations with thermal noise. Furthermore, thermal noise coupled with vesicle dynamics in TR is responsible for generation of wrinkling instability, investigated both experimentally and numerically (M.Levant et al., Europhys. Lett. 107, 28001 (2014).
BRIEF ACADEMIC/EMPLOYMENT HISTORY
Professor Emeritus at Weizmann Institute of Science, Rehovot, Israel
RECENT RESEARCH INTERESTS
Soft Matter Dynamics and Hydrodynamics (vesicles, micro-capsules, RBC etc), polymer dynamics and hydrodynamics, elastic turbulence, hydrodynamic turbulence and turbulent drag reduction