List of Events



MRSEC SEMINARS-EVENTS

MRSEC Seminars are normally held at 4:00 p.m.  in Abelson 229, unless otherwise noted.
Find  Abelson-Bass-Yalem building on the  interactive map.
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Thursday, September 4, 2014 
12 p.m.

Room: Abelson 229, Brandeis University
MRSEC Seminar
Speaker: Douglas Brumley, MIT Dept of Civil and Environmental Engineering
Title: Flagellar Synchronization Through Direct Hydrodynamic Interactions
Abstract: Flows generated by ensembles of flagella are crucial to development, motility and sensing, but the mechanisms behind this striking coordination remain unclear. We present novel experiments in which two micropipette-held somatic cells of Volvox carteri, with distinct intrinsic beating frequencies, are studied by high-speed imaging as a function of their separation and orientation. Analysis of time series shows that the interflagellar coupling, constrained by lack of connections between cells to be hydrodynamical, exhibits a spatial dependence consistent with theory. At close spacings it produces robust synchrony for thousands of beats, while at increasing separations synchrony is degraded by stochastic processes. Manipulation of the relative flagellar orientation reveals in-phase and antiphase states, consistent with dynamical theories. Flagellar tracking with exquisite precision reveals waveform changes that result from hydrodynamic coupling. This study proves unequivocally that flagella coupled solely through a fluid can achieve robust synchrony despite differences in their intrinsic properties.
Host:  Z. Dogic





Thursday, September 18, 2014 
4 p.m.

Room: Abelson 229, Brandeis University
MRSEC Seminar
Speaker: Anupam Sengupta, Dept. of Civil and Environmental Engineering at MIT
Title: Towards Topological Microfluidics: Harnessing surface, elastic and viscous interactions at micro-scales
Abstract: The hydrodynamic properties of nematic liquid crystals are characterized by a complex mutual coupling between flow, viscosity, and nematic order. While the flow behaviour of nematic bulk samples is well known, corresponding studies in microfluidic settings are still at an early stage. The presence of the four confining channel walls—and in particular the nature of the surface anchoring of the nematic order on the walls—adds new phenomena to the already rich and multi-faceted flow behaviour. Topological Microfluidics harnesses these interactions, and provides a novel pathway to engineer templates to tune flow and topology. Through easily accessible experimental parameters, we produce, position and navigate topological defects in liquid crystal, which are then used as soft rails for guided transport of colloids and droplets, or light beam for photonic applications. Currently, we are developing tools for generating topological motifs through hydrodynamic singularities. Under appropriate flow and boundary conditions, one can hierarchically tune the strength of the resulting topological defects. The results are aimed towards motivating a fundamental theoretical understanding of the coupling interactions: specifically those between the hydrodynamic and the topological singularities. I will conclude the talk with some emerging concepts in Topological Microfluidics and their possible relevance in microbial biophysics.
https://sites.google.com/site/anupamsengupta/
Host: Z. Dogic




Thursday, October 16, 2014 
4 p.m.

Room: Abelson 229, Brandeis University
MRSEC Seminar
Speaker: Thomas Miller, Dept of Chemistry, Caltech
Title: TBA
Abstract: TBA
Host: M. Hagan



Friday, November 7, 2014 
4 p.m.

Room: Abelson 229, Brandeis University
MRSEC Seminar
Speaker: David L. Hu, Dept. of Mechanical Engineering Georgia Tech
Title: TBA
Abstract: TBA
Host: Z. Dogic