Fabrication of Microfluidic Devices Utilizing Stereolithographic 3D Printing

While microfluidic devices provide various advantages in scaled biomedical applications, the device fabrication process requires extensive labor and skill, as well as access to appropriate clean room facilities. Recent studies have been conducted in the use of 3D printing applications as a replacement for the more tedious photolithography and soft lithography in the fabrication of these devices, accelerating and streamlining the design process. In this experiment, an Autodesk Ember stereolithographic 3D printer is used to generate molds for the fabrication of PDMS microfluidic channels. To assure accuracy of the final molds, several resolution models of various dimensions and geometries were printed using variable and non-variable exposure settings; these devices were then characterized using a DektakXT profilometer, an epifluorescence microscope, and ImageJ image processing software. From this analysis, it was determined that the height and width of the printed features was different than expected dimensions; the percent of deviation from the expected value also appeared to vary based on the magnitude of the height and width. A design of experiment was conducted and analyzed using Minitab to test for a correlation between the height and the width of the printed features. This resolution data was then compiled and used to generate calibration curves for the desired feature height and width; several prints of channels of various dimensions were then printed to test the effectiveness of the calibration curves. As a final proof of concept, two additional prints, one using the drafted calibration curves and one without, of an initial microfluidic junction design were also tested. In future studies, additional resolution models will be analyzed to improve upon the accuracy of the dimensional calibrations curves, and various microfluidic devices will be fabricated and compared to existing devices created using traditional photolithographic methods.