MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Doctoral Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Multiphase flow and control of fluid path in microsystems

Author(s)
Jhunjhunwala, Manish
Thumbnail
DownloadFull printable version (98.23Mb)
Other Contributors
Massachusetts Institute of Technology. Dept. of Chemical Engineering.
Advisor
Klavs F. Jensen.
Terms of use
M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582
Metadata
Show full item record
Abstract
Miniaturized chemical-systems are expected to have advantages of handling, portability, cost, speed, reproducibility and safety. Control of fluid path in small channels between processes in a chemical/biological network is crucial for connecting process elements. We show complete separation of individual phases (phase routing) from two-phase gas-liquid and liquid-liquid (aqueous-organic) mixtures on microscale. To provide for robust interfacing of operations in a network, we demonstrate this ability over a wide range of two-phase flow conditions, including transient ones. Enabled by the technique for complete separation of individual phases from two-phase mixtures, we show mixing of liquids by introduction of a passive gas-phase and demonstrate integration of mixing, reaction and phase separation on a single platform. Additionally, we use the principles developed for phase routing to design microfluidic valves that do not rely on elastic deformation of material. Such valves can be used in a variety of chemical environments, where polymer-based deformable materials would fail.
 
(cont.) We show a concept for realization of logic-gates on microscale using appropriate connections for these valves, paving the way for design of automation and computational control directly into microfluidic analysis without use of electronics. Further, we use the phase separation concept for sampling liquid from gas-liquid and liquid-liquid mixtures. Such sampling ability, when coupled with a suitable analysis system, can be used for retrieving process information (example mass-transfer coefficients, chemical kinetics) from multiphase-processes. We provide evidence of this through estimation of mass-transfer coefficients in a model oxygen-water system and show at least an order-of-magnitude improvement over macroscale systems. Controlled definition of fluid path enabled by laminar flow on microscale is used in a large number of applications. We examine the role of gravity in determining flow path of fluids in a microchannel. We demonstrate density-gradient-driven flows leading to complete reorientation of fluids in the gravitational field.
 
(cont.) We provide estimates of the time and velocity scales for different parameter ranges through two-dimensional and three-dimensional finite-element models, in agreement with experimental observations. We believe this thesis addresses a number of both: system and fundamental issues, advancing applications and understanding of microfluidic networks.
 
Description
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2005.
 
Includes bibliographical references.
 
Date issued
2005
URI
http://hdl.handle.net/1721.1/37456
Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Publisher
Massachusetts Institute of Technology
Keywords
Chemical Engineering.

Collections
  • Doctoral Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.