Effects of processing parameters on the micro-channels replication in microfluidic devices fabricated by micro injection molding

Fabrication of polymer microfluidics devices such as micromixer by injection molding becomes popular increasingly. It is always involved with the replication of micro-channels for fluids. The quality control of the produced micro-channels is a key issue in the microfluidics devices fabrication. This paper studies the effects of processing conditions on the cross-sectional profile and the dimensions of the micro-channel such as its width and depth. Design of experiment (DOE) using Taguchi method and a L18 (2¹ × 3⁷) orthogonal array is used to carry out the optimization of the processing conditions in order to achieve the closest micro-channel width to the micro-feature width of the mold insert. Eight processing parameters are considered in DOE and their significances are investigated in analysis of variances (ANOVA). They are pre-drying, melt temperature, mold temperature, injection velocity, injection pressure, holding pressure and holding time, as well as cooling time.