ME689A

MICROSCALE TRANSPORT PHENOMENA

Credits:

 

 

3-0-0-9

 

Syllabus:


Introduction; Channel Flow; Dissipation effect, Compliance of channel wall. Transport Laws; Boundary slip, Momentum accommodation coefficient, Thermal accommodation coefficient, Diffusion, Dispersion and Mixing; Surface Tension Dominated Flows; Thermo-capillary flows, Diffuso-capillary flows, Electrowetting, Charged Species Flow; Electro-osmosis, Electrophoresis, Dielectrophoresis, Magnetism and Microfluidics;. Microscale Heat Conduction; Energy Carriers, Scale effects, Kinetic theory, Boltzmann transport theory, Microscale Convection; Flow boiling, Condensation, Micro heat pipes, Micro Fabrication; Measurements.

Lecture-wise Breakup:


I. Introduction:

  • Historical Perspectives, Definition, Biological Systems, Analogy with computational platforms, Benefits, Application Examples: Micro Electro-Mechanical Systems (MEMS), Lab on a Chip, Micro reactor, Micro heat pipes, Micro sensors, Micro actuators,  Micro Pumps, Drug delivery systems. (1 lecture)

II. Scaling Analysis:

  • Natural systems, Parallel plate capacitor for sensor, Micro droplets, Micro resonator, Micro reactor, Micro heat exchangers (1 lecture)

III. Channel Flow:

  • N-S equations, Dimensional Analysis, Hydraulic resistance, Arbitrary shaped channel flow, Elliptic, Equilateral and Rectangular channel flow, Dissipation effect, Compliance of channel wall. (3 lectures)

IV. Transport Laws:

  • Boundary slip, Momentum accommodation coefficient,  Thermal accommodation coefficient, Thermal creep, Knudsen Compressor, Slip flow boundary condition in liquids and gases, Physical parameters affecting Slip, Slip Model Derivation, Compressibility effect, Slip flow between parallel plates and Couette  flow, Introduction to molecular modeling, Deterministic molecular modeling, Statistical molecular modeling, Boltzmann Equation, Direct Simulation Monte-Carlo (DSMC) Method. (4 lectures)

V. Diffusion, Dispersion and Mixing:

  • Random walk model of diffusion, Stokes-Einstein Law, Fick's law, Governing equation of multicomponent system, Characteristic nondimensional parameters, Fixed planar source diffusion, Constant planar source diffusion,  Convection-diffusion equation, Taylor dispersion, Micromixer examples, Soluble or rapidly reacting wall, Reverse osmosis channel flow. (4 lectures)

VI. Surface Tension Dominated Flows:

  • Microscopic model of surface tension, Gibbs free energy, Young-Laplace equation, Contact angle (Static and Dynamic), Wetting, Super hydrophobicity and hydrophilicity, Coating flows, Thermo-capillary flows, Thermo capillary pump, Diffuso-capillary flows, Electro-wetting, Taylor flows, Two-phase liquidliquid flows, Clogging pressure, Digital microfluidics, Marangoni convection and instability. (4 lectures)

VII. Charged Species Flow:

  • Electrical conductivity and charge transport, Electrohydrodynamic transport theory, Transport equation of dilute binary electrolyte, Electrolytic cell, Electric double layer or Debye sheath, Electro-kinetic phenomena, Electro-osmosis, Electro-osmotic micro-channel systems, Electro-osmotic Pumps, Electrophoresis, Dielectrophoresis, Particle trapping. (4 lectures)

VIII. Magnetism and Microfluidics:

  • Introduction to magnetism theory, Magnetic beads, Magnetic force, Motion of magnetic particles, Magnetophoresis, Magnetic fluid flow fractionation, Magnetic sorting, Magnetic separation, Ferrofluidic pump, Heat transfer enhancement using ferrofluid, Magneto-hydrodynamics, MHD based micro-pump. (3 lectures)

IX. Microscale Heat Conduction:

  • Energy Carriers, Time and length scales, Scale effects, Fourier's law, Hyperbolic heat conduction, Kinetic theory, Electron thermal conductivity in metals, Lattice thermal conductivity, Scale effects of thermal conductivity, Boltzmann transport theory, Heat transport in thin films and at solid-solid interfaces, Heat conduction in semiconductor devices and interconnects, Laser heating. (4 lectures)

X. Microscale Convection:

  • Scaling laws, Temperature jump boundary condition, Convection in parallel plate channel flow and Couette flow with and without viscous dissipation, Similarity and dimensionless parameters, Flow boiling in micro channels, Mini-channel versus micro-channel, Nucleate and convective boiling, Dryout incipience quality, Saturated and sub-cooled flow boiling, Condensation heat transfer in mini-micro channels, Micro heat pipes (4 lectures)

XI. Micro Fabrication:

  • Functional materials, Lithography, Subtractive technique, Etching, Wet etching, Dry etching, Deep reactive ion etching, Additive techniques, Physical vapor deposition, Chemical vapor deposition, PDMS based molding, Bonding, Laser micro fabrication technique. (4 lectures)

XII. Measurements:

  • Micro scale velocimetry,  Microscale thermometry (3 lectures)

Reference Books:

  1. Introduction to Microfluidics, P. Tabeling, Oxford University Press, 2005

  2. Microflows & Nanoflows: Fundamental and Simulation, G. Karniadakis, A. Beskok, N. Aluru, Springer Publication, 2005

  3. Microfluidics for Biotechnology, J. Berthier and P. Silberzan, Artech House, 2006.

  4. Theoretical Microfluidics, H. Bruus, Oxford University Press, 2008.

  5. Fundamentals and Applications of Microfluidic 2nd edition, N.T. Nguyen and S.T. Wereley, Artech House, 2006 .