Rapid and cost-effective fabrication of selectively permeable calcium-alginate microfluidic device using "modified" embedded template method

Abstract

In this paper, we have presented a non-lithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. To demonstrate the versatility of the presented method, we have demonstrated two different strategies to fabricate serpentine long delay channels without using any sophisticated microfabrication techniques, in formal lab atmosphere. The procedure presented here, also, enables the preparation of a multilayered microfluidic device with channels of varying dimensions, in a single device without using any sophisticated micromachining instrumentation. In addition, we have also qualitatively studied the diffusion of small and large molecules from a Ca-alginate based microfluidic device and proposed a method to effectively control the out-flow of macro biomolecules from the crosslinked Ca-alginate matrix to create a selectively permeable matrix required for various biological and biomimetic applications, as mentioned in the Introduction section of this work.

Figure 1

Schematic of the fabrication of long delay channel Ca-alginate microfluidic device using embedded template method (Scheme not to the scale). Please see text for full description.

Figure 2

Schematic of modified embedded template method for the fabrication of serpentine long delay channel Ca-alginate microfluidic device (Scheme not to the scale). Please see text for full description.

Figure 3

Fabrication of multilayered Ca-alginate device using modified embedded template method. (a) Framework of double layered embedded template. (b) Ca-alginate microfluidic device after removal of templates.

Figure 4

Fluorescence microscopic image of Ca-alginate device half coated with chitosan, showing diffusion of GFP in non-coated part of the channel.

Figure 5

Control of diffusion mass transfer of GFP from microchannel into Ca-alginate matrix at different periods both before and after coating with different concentrations of chitosan. Inset represents the image analysis of gray scale vs. distance in pixel.

Figure 6

Diffusion of phenol red into the alginate matrix through the microchannel both before and after coating with chitosan at different time intervals.