THE UNIVERSITY OF AT AUSTIN Roger T. Bonnecaze Department of Chemical Engineering Institute for Computational Engineering & Sciences Texas Materials Institute Simulation, Theory and Experiments on Multiphase & Interfacial Flows Discovery & understanding of fundamental fluid mechanical phenomena in multiphase and interfacial flows Application of understanding to modeling, design and use of man-made and natural processes Research Theme:

THE UNIVERSITY OF AT AUSTIN Current Research Activities Multiphase flow of suspensions & emulsions Rheology of pastes Self-assembly of nanoparticles Fluid management in Step-and-Flash Imprint Lithography Jay Norman L. Srivatsan Brooks Rabideau Shravi Reddy Jyoti Seth Bomi Nam Post-doctoral researcher Dr. Hebri Nayak Current research projects include: Graduate Students

THE UNIVERSITY OF AT AUSTIN Multiphase Flow of Suspensions Inline sensor Flow System N b =18.6 ExperimentalTheoretical N b =

THE UNIVERSITY OF AT AUSTIN Oscillating Flow – MRI Imaging Neutrally buoyant particles generally migrate to center Except with high frequency pressure-gradient oscillations Axial concentration variations occur as well w/oscillations

THE UNIVERSITY OF AT AUSTIN Self-Assembly of Nanoparticles Development of fundamental understanding of the dynamics of pattern formation in colloidal and nanoscale systems Development of fundamental understanding of the dynamics of pattern formation in colloidal and nanoscale systems Novel applications for materials with nanoscale patterns of particles as “active material” or templating agent Novel applications for materials with nanoscale patterns of particles as “active material” or templating agent Photonic Devices Joannopoulos et al. High-density Magnetic Media

THE UNIVERSITY OF AT AUSTIN Simulation as a Guide Wall Charge and Ordering  = 1%,  red = 42  wall =  wall = -250 Phase Diagram

THE UNIVERSITY OF AT AUSTIN Fluid Management in SFIL  Photolithography requires expensive optics systems & is limited by wavelength of light  Imprint lithography is high throughput and low cost  Template takes advantage of E-beam technology – smaller features are possible SFIL is a favorable alternative to traditional lithography methods:

THE UNIVERSITY OF AT AUSTIN Critical Fluid Dynamics in SFIL Imprint time Base layer thickness Filling by multiple drops Preferential flow paths Arresting of droplet flow front Filling of template features Monomer drops Small feature pattern Large feature

THE UNIVERSITY OF AT AUSTIN SFIL Simulation of Feature Filling Development of large scale simulations -Group & ICES parallel computing clusters Development of micromechanics and multi- phase continuum mechanics Develop and apply experimental methods to discover & characterize new phenomena Research Methods