Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide)
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.
| Main Author: | |
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| Other Authors: | |
| Format: | Thesis |
| Language: | eng |
| Published: |
Massachusetts Institute of Technology
2009
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| Online Access: | http://hdl.handle.net/1721.1/44889 |
| _version_ | 1826197767142244352 |
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| author | Reticker-Flynn, Nathan Edward |
| author2 | Sang-Gook Kim. |
| author_facet | Sang-Gook Kim. Reticker-Flynn, Nathan Edward |
| author_sort | Reticker-Flynn, Nathan Edward |
| collection | MIT |
| description | Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. |
| first_indexed | 2024-09-23T10:52:49Z |
| format | Thesis |
| id | mit-1721.1/44889 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T10:52:49Z |
| publishDate | 2009 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/448892019-04-11T00:11:26Z Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) Reticker-Flynn, Nathan Edward Sang-Gook Kim. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Mechanical Engineering. Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. In title on title page, "N" appears as italic. Includes bibliographical references (leaves [181]-185). A compact printable microfluidic valve composed of poly(N-isopropylacrylamide) has been designed, fabricated, and tested. The design of the valve consists of filling microwells with poly(NIPAAm) and bonding PDMS channels above them. This filling is achieved using thermal inkjet printing of a prepolymer solution and subsequent polymerization using UV irradiation. When the gel is swollen, it blocks flow from passing through the channel. Upon heating, the gel shrinks and allows flow in the channel. Poly(NIPAAm) is a thermosensitive hydrogel that exhibits an inverse temperature expansion behavior. When the temperature of the swollen gel is raised above a lower critical solution temperature (LCST) of approximately 32°C, the gel becomes hydrophobic. This change in hydrophobicity results in expulsion of the water molecules from within the hydrogel network, thus resulting in shrinking of the gel. By adding magnetic nanoparticles to the hydrogel and exposing it to an external magnetic field, volumetric change of the hydrogel can be locally and externally induced. External heating of the magnetic nanoparticles, however, is not included in this thesis. In order to ensure shrinkage that is predictable in favor of flow control, microanchor structures have been designed, modeled, and fabricated at the bottom of the microwells. These microanchors hold the poly(NIPAAm) at the bottom of the plug such that the shrinkage of the gel always acts to open the flow channel at the top yielding a minimum pressure drop. Design decisions were made using the principles of Axiomatic Design in order to minimize the response time and pressure drops in the valve. Modeling of the underlying mechanisms is described along with the application of these models to the final device. Results of fabrication suggest the feasibility while also eliciting possible improvements to the fabrication process. (cont.) Profilometry measurements of the swollen and shrunken valves reveal flow control operation as intended. Additionally, design and modeling of magnetic heating using mixed-in nanoparticles is presented. A fabrication plan designed to include this mechanism is proposed. by Nathan Edward Reticker-Flynn. S.M. 2009-03-16T19:56:24Z 2009-03-16T19:56:24Z 2008 2008 Thesis http://hdl.handle.net/1721.1/44889 302413483 eng 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 185 leaves application/pdf Massachusetts Institute of Technology |
| spellingShingle | Mechanical Engineering. Reticker-Flynn, Nathan Edward Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title | Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title_full | Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title_fullStr | Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title_full_unstemmed | Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title_short | Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide) |
| title_sort | design and fabrication of microfluidic valves using poly n isopropylacrylamide |
| topic | Mechanical Engineering. |
| url | http://hdl.handle.net/1721.1/44889 |
| work_keys_str_mv | AT retickerflynnnathanedward designandfabricationofmicrofluidicvalvesusingpolynisopropylacrylamide |