The ability to generate a range of concentrations of various solutions rapidly and conveniently is an ongoing need in biotechnology. In this thesis we demonstrate how we took advantage of the full process control afforded by our recent custom high resolution 3D printer and resin advances to realize highly integrated and miniaturized microfluidic components for simultaneous on-chip serial dilution for dose-response assays. With judicious selection of mixed layer thicknesses and pixel-by-pixel dose control, we show that the diameter of 3D printed membrane valves can be reduced from 300 µm to 46 µm. We further introduce an entirely new kind of 3D printed valve, termed a squeeze valve, in which the active area is reduced still further to 15 µm x 15 µm. We demonstrate and characterize pumps based on each type of valve and introduce a short (<1 mm long) high aspect ratio channel that enables rapid diffusion-based mixing. We show that combining two pumps with this diffusion mixing channel results in a highly compact 1:1 mixer component. Connecting 10 of these components in series yields a miniature 10 stage 2-fold microfluidic serial dilution module that from two solution inputs simultaneously generates 10 output concentrations that cover three orders of magnitude. We show the efficacy of our serial dilution approach by demonstrating an assay for dose-dependent permeabilization of A549 cells in different concentrations of digitonin integrated into a single device. Our demonstration of component miniaturization in conjunction with a high degree of integration illustrates the promise of 3D printing to enable highly functional and compact microfluidic devices for a variety of biomolecular applications.



College and Department

Ira A. Fulton College of Engineering and Technology; Electrical and Computer Engineering



Date Submitted


Document Type





microfluidics, 3D printing, serial dilution, dose-response assays



Included in

Engineering Commons