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MICDE Seminar: Narayana R. Aluru, Professor, Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign
March 14, 2019 @ 3:00 pm - 4:00 pm
Bio: Professor Aluru studies problems at the crossroads of mechanical engineering, electrical engineering, materials science and chemical engineering. His work in the area of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) revealed previously unknown nonlinear dynamic phenomena, such as complex oscillations, period doubling bifurcation to chaos, and U-sequence. These insights led him to perform fundamental studies on thermoelastic damping in MEMS and to develop a new model to predict thermoelastic damping for complex nonlinear oscillations encountered in NEMS.
In another effort, he developed the first bio-MEMS and microfluidics models for the analysis and design of lab-on-a-chip applications, as well as mathematical models for pH- and electric field-responsive hydrogels-materials with potential applications in small-scale sensing and actuation.
Professor Aluru also studies the unique physics that occur at the nanometer level. He discovered several new physical phenomena through nanofluidics research, including charge inversion, flow reversal, anomalously immobilized water, asymmetric dependence of fluid and ion transport on surface charge, and enhanced conductivity in nanopores. His recent investigations of surface diffusion demonstrated that liquid molecules move as much as 30 times faster over a solid surface when that surfaced is only partially covered by such molecules, and that larger molecules move faster on a partially covered surface than shorter ones do. His other work in nanofluidics includes the multiscale modeling of the transport of water and other ions through membranes, studying the function of biological channels in the membranes of living cells, investigating the use of carbon nanotubes to filter pathogens and other toxins out of water, and exploring the use of carbon and boron nanotubes to speed the removal of salt from water during reverse osmosis.
COMPUTATIONAL NANOSCALE HYDRODYNAMICS
Many applications in biology, engineering and science rely on efficient hydrodynamic transport through nanometer scale pores and channels. For example, channels and pores in cellular membranes regulate the functionality of the cell by selectively and efficiently exchanging water and ions between extra and intra cellular environments. Selective pores in ultrathin membranes have been shown to be highly efficient for water desalination and power generation. Classical theories often fail to describe fluid physics at nanometer scale. For example, density layering, size dependent fluid properties, restricted translational and rotational motions, charge inversion, flow reversal and several other important phenomena have been observed at nanometer scale. The focus of this talk is to develop efficient theories and computational approaches to accurately describe fluid physics at nanometer scales. First, we will introduce an empirical potential-based quasi-continuum theory (EQT) to accurately predict the structure of confined fluids. We show that the density layering from EQT matches well with molecular dynamics (MD) and EQT is many orders of magnitude faster compared to MD. Next, we show that the EQT framework can be combined with the generalized Langevin theory to compute diffusion of confined fluids and with the classical Navier-Stokes equations to compute the transport of confined fluids. We will show several examples to demonstrate the accuracy and efficiency of the quasi-continuum theory for confined fluids.
Prof. Aluru is being hosted Professors Krishna Garikipati and Eric Michielssen. If you would like to meet Prof. Aluru, please send an email to firstname.lastname@example.org. If you are an MICDE student or fellow, or a post-doc, and would like to join Prof. Aluru for lunch, please RSVP here.