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David Leighton

David Leighton

Email: dtl@nd.edu

Phone: 574-631-6698

Office: 179 Fitzpatrick Hall

Education

Ph.D, Stanford University, 1985

M.S., Stanford University, 1981

B.S., Princeton University, 1980

Biography

Recent work has demonstrated that particles will migrate across streamlines in the viscous flow of concentrated suspensions due to gradients in concentration and gradients in the applied shear stress. Such migration processes are particularly important in the casting of composite materials, such as in the injection molding of filled polymers and in the formation of solid rocket propellant motors. New research has also demonstrated that bidisperse suspensions (suspensions of particles which have two distinct sizes) and polydisperse suspensions may undergo shear-segregation can lead to a substantial effect on the burn characteristics. Dr. Leighton's group is currently investigating this segregation phenomenon and developing a constitutive equation for the migration capable of predicting size segregation in complex flow geometries.

In a much different area of research, Dr. Leighton's group has been developing a radically new approach to electrophoretic separations. Electrophoresis (the separation of proteins or other large molecules based on their electrophoretic mobility) has long been used as an analytical tool for the identification and isolation of specific proteins from a solution. However, scale up to production levels remained largely unsuccessful. In recent work Dr. Leighton's group has developed a new approach, called zetafiltration, which combines an oscillatory electric field with an oscillatory cross-flow to separate proteins and nanoparticles at throughputs far higher than possible using conventional techniques. This new separation technique is currently being demonstrated experimentally.

Publications

Debashis Dutta and David T. Leighton, Jr. A Low Dispersion Geometry for Microchip Separation Devices. Analytical Chemistry, 74:1007-1016, 2002. 

Debashis Dutta, Arun Ramachandran and David T. Leighton Jr. Effect of channel geometry on solute dispersion in pressure-driven microfluidic systems. Microfluidics and Nanofluidics, 2:275-290, 2006. 

Arun Ramachandran and David T. Leighton. The influence of secondary flows induced by normal stress differences on the shear-induced migration of particles in concentrated suspensions. Journal of Fluid Mechanics, 603:207-243, 2008. 

Ramachandran A., Lowenberg, M., Leighton, D. T. A constitutive equation for droplet distribution in unidirectional flows of dilute emulsions for low capillary numbers. PHYSICS OF FLUIDS, 22:art:083301, 2010. 

Ramachandran A. and Leighton, D. T. Particle migration in concentrated suspensions undergoing squeeze flow. JOURNAL OF RHEOLOGY, 54:563-589, 2010. 

Awards

John A. Kaneb Teaching Award
Given on April 27, 2004 by University of Notre Dame

Presidential Young Investigator Award
Given on December 31, 1986 by National Science Foundation

John A. Kaneb Teaching Award
Given on April 11, 2000 by University of Notre Dame

Summary of Activities/Interests

Professor Leighton's research interests are in the areas of fluid mechanics and separation processes. Of particular interest is the way in which mathematics may be applied to improve our understanding of physical processes that occur in these areas. Current research projects include the study of flow-induced microstructure in concentrated suspensions, shear-induced migration and segregation in bidisperse suspensions, dispersion in chip-based micro-laboratories, and zetafiltration, a novel electrophoretic separation process.