Start
Aug 27, 2015 - 17:00
End
Aug 27, 2015 - 18:00
Venue
Room # 118 Chem. Engg. Dept.
Event Type
Speaker
Dr. VijayKumar Chikkadi postdoctoral fellow at Ecole Normale Supreieure Lyon (ENS Lyon).
Title
Collective motion and anomalous diffusion of active colloidal rollers
Abstract : The emergence of collective motion on large length scales is the hallmark of a wide variety of active living matter. Bird flocks fish schools bacterial swarms and etc are a few examples. The origin of this robust behavior lies in the microscopic interactions at the individual level. Due to complexity of the systems it is often challenging to measure and describe them theoretically. Here we have developed a model system of active colloidal rollers that allows a quantitative description of microscopic interactions between the particles. Under confinement these colloidal rollers are found to display self organisation in the form of a steadily rotating macroscopic vortex. The system undergoes a phase transition from an isotropic-gas phase to a heterogeneous polar-liquid vortex phase when the density of the rollers exceeds a critical density. We will present experimental results and theoretical arguments to support these observations. Towards the end of the talk I will also present a few recent results on the anomalous diffusion of colloidal rollers in a heterogeneous media.Short bio : Dr. VijayKumar Chikkadi is currently interested in colloidal soft matter and microscopic imaging techniques. He completed his PhD at the University of Amsterdam with Peter Schall and Daniel Bonn. During his PhD the applicant did experimental work on collective vibrations and deformation of colloidal glasses. He developed a microscopic picture of the flow of colloidal glasses and a new technique to visualize collective modes of vibrations in colloidal solids . Following his PhD he was at the Leiden University and the Weizmann Institute as a postdoctoral researcher. Currently the applicant is a CNRS postdoctoral fellow at Ecole Normale Supreieure Lyon (ENS Lyon) where he is working with Denis Bartolo on colloidal active matter.
Mandatory for CL 702/704 course.