Self-assembled synthesis and characterization of microchannels in polymeric membranes

Document Type

Article

Source Publication Title

Journal of Applied Physics

First Page

24701

DOI

http://dx.doi.org/10.1063/1.4729526

Abstract

This article describes a novel self-assembly approach to create microchannels in polydimethylsiloxane (PDMS) membranes using poly(ethylene oxide) (PEO) and polyurethane (PU). The interactions between hydrophilic PEO/PU and hydrophobic PDMS, as it cross-links, result into PEO/PU pushed out of the bulk PDMS. As this occurs, PEO/PU particles leave behind their tracks. PEO depicts ease of handling, better inherent alignment, and excellent repeatability. Fourier transform infrared spectroscopy, optical/confocal laser scanning microscopy, and fluid flow measurements are done to characterize the microfluidic channels. These channels have a circular cross-section and are parallel to each other. PEO generates smaller channels compared to PU. The diameter, arrangement, and height of these channels are seen to depend on temperature; for example, channel length increases linearly with temperature. An interdependent relationship between temperature, pore size, and number of pores is also exhibited. During phase separation of hydrophilic and hydrophobic materials, interface shows concentric circular arrangements of hydrophilic molten polymer. The circular pattern shows almost similar radial change in size. The flow behavior of colored ink solutions shows higher velocity at the entrance of microchannels which decreases to sustained lower velocity as fluid travels farther in the microchannels. The fabrication of membrane does not need lithography or etching, and channels are self-assembled from bottom-up interactions. These microchannel membranes can have applications in drug delivery, cell culture studies, mixing of solutions, separation of mixtures, lab-on-a-chip, etc.

Disciplines

Electrical and Computer Engineering | Engineering

Publication Date

7-19-2012

Language

English

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