Levich Institute Seminar Announcement, 02/13/2007
Steinman Hall, Room #312
(Chemical Engineering Conference Room)
Dr. Anil Kumar
City College of CUNY
"Electric Field Induced Phenomena in Suspensions"
During the last decade, microfluidic devices have attracted a considerable degree of attention due to the small sample volumes requirement for analysis purpose. This is particularly important and suitable for various biological samples as they are either highly expensive or, in most cases, are available in extremely small quantities. The small dimensions of these devices, however, create problems, such as the large pressure required to pump the fluid into these devices as well as adding to the practical difficulties in performing manipulation within these devices from the outside world. In this regard, electric-field based approaches are well suited and advantageous as they could easily be integrated into these devices and allow for the control of the on-chip operation from the outside. Furthermore, the small dimensions of such devices become actually an added advantage because, at such small dimensions, an extremely strong electric field of ~1kV/mm could easily be generated by applying only several Volts of an electrical signal across a distance of a few microns.
During my talk, I will demonstrate the effectiveness of AC electric field based techniques for performing a variety of unit operations such as: concentrating
particles into focused regions, separating biological and non-biological species, positioning of particles into prespecified locations, as well as a conveyer-belt approach for transporting a
collection of particles in a controllable manner. Next, I will present a method for transporting a liquid using an electric field through a "50-micron diameter capillary" microchannel and will also
introduce a straightforward method for measuring key transport parameters in "free-solution capillary electrophoresis" which forms the core of various analytical chemistry separations processes.