Characterization of rapid PDMS casting technique utilizing molding forms fabricated by 3D rapid prototyping technology (RPT)

In this work we characterize a novel possibility for PDMS (PolyDiMethylSiloxane) casting/ micromolding methods with the utilization of molding forms fabricated by a commercially available novel acrylic photopolymer based 3D printing method. The quality and absolute spatial accuracy of 1) different 3D printing modes ('matt' vs. 'glossy'); 2) the molded PDMS structures and 3) the subsequently produced complementary structures made of epoxy resin were investigated. The outcome of these two form transfer technologies were evaluated by the cross sectional analysis of open microfluidic channels (trenches) with various design. Our results reveal the spatial accuracy in terms of real vs. CAD (Computer Aided Design) values for the 3D printed acrylic structures and the limits of their form transfer to PDMS, then to epoxy structures. Additionally the significant differences between the various spatial directions (X, Y, Z) have been characterized, and the conclusion was drawn that the 'glossy' printing mode is not appropriate for 3D printing of microfluidic molds.