Levich Institute Seminar Announcement, 08/31/2010
Tuesday, 08/31/2010
2:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Professor Susan Muller
University of California, Berkeley
Department of Chemical Engineering

"Experiments in Microfluidic Stagnation Point Flows: Trapping, Deforming, and Analyzing DNA"


We have designed and fabricated a series of microdevices that create stagnation points at which microscale objects may be trapped and subjected to flow forces. In the simplest of these, the cross-slot, microscale objects such as DNA may be trapped and stretched in a planar extensional flow to a steady-state extension that is determined by the flow strength, as demonstrated by the pioneering work of Chu and co-workers (Science, 276, 1997). We will present three extensions of this idea: 1) the design and use of more complex devices to allow the systematic variation of flow type as well as flow strength near the stagnation point (the “microfluidic four-roll mill”) , 2) the use of stagnation point flows for single molecule sequence detection and studies of enzyme binding kinetics on DNA, and 3) the use of stagnation point flows for studies of the dynamics of vesicles.


Susan J. Muller is currently Associate Dean of the Graduate Division, and Professor of Chemical Engineering, at the University of California, Berkeley. Professor Muller has worked on problems related to polymer fluid mechanics, rheology, and microfluidics for over 25 years at MIT, Schlumberger Cambridge Research, AT&T Bell Laboratories, and the University of California, Berkeley. Particular research interests include viscoelastic instabilities in Taylor-Couette flows, the role of polymer-solvent interactions in determining macroscopic flow behavior, shear-induced migration of polymers in dilute solutions, and the behavior of DNA and microscale objects in microfluidic devices. Examples of some recent research projects, selected publications, and a list of “Muller group” members and alumni can be found at her research group website: http://www.cchem.berkeley.edu/sjmgrp/. Muller holds a B.S.E. in chemical engineering from Princeton University, and a Ph.D. in chemical engineering from M.I.T.


The role of weak elasticity in high Reynolds number Taylor-Couette flows and applications to drag reduction, the development of microfluidic flow control strategies, and the use of microfluidic stagnation point flows for trapping and manipulating microscale objects.