Sandip Ghosal

Associate Professor

Phone: (847) 467-5990
Fax: (847) 491-3915
E-mail: s-ghosal@northwestern.edu

Web Page:

http://www.mech.northwestern.edu/fac/ghosal/

Research: Fluid Mechanics - Micro scale flows near charged interfaces

Professor Ghosal studies phenomena connected with the motion of fluids in the vicinity of electrically charged interfaces. Matter is electrically neutral on macroscopic scales, but interfaces of materials are almost always charged. We are reminded of this in small ways in our daily lives; for example a nylon comb or a plastic ruler will attract bits of paper and deflect a narrow stream from a faucet if you first rub it on your clothes or hair. These interfacial forces being proportional to the surface area are however often dwarfed by volume forces such as gravity. The situation changes dramatically on very small scales (roughly a 100 micron or less). At an interface of a solid and liquid, these electrical forces can drive a significant flow. Such micro-scale flows have important applications in recently developed and rapidly evolving technologies such as microfluidics and nanotechnology. They are also at the heart of biological processes; for example, the condensation of DNA on nucleosomes, the transport of protein precursors across intracellular membranes etc. can be studied as the mechanics of charged elastic rods (biopolymers) in a viscous fluid (water).