Fabrication of robust tooling for mass production of polymeric microfluidic devices

Polymer microfluidic devices are gaining popularity for bio-applications. In both commonly used methods for the fabrication of polymer microfluidic devices, i.e. injection molding and hot-embossing, the quality of a mold insert is of high importance. Micro powder injection molding (mu PIM) provides a suitable option for metal mold insert fabrication. In this paper, two mold inserts with micro-features of different patterns and sizes were produced using 316L stainless steel powder and an in-house binder system. The mold inserts were successfully used to produce cyclic olefin copolymer (COC, trade name TOPAS) micromixer plates with micro-channels of widths 100 mu m and 50 mu m. Compared with CNC-machined hot work steel mold inserts, the quality of the micro-channels is better as far as geometrical quality and dimensional tolerance are concerned. However, surface finish and flatness of the mu PIM mold inserts are inferior to those of CNC-machined mold inserts.