Properties and performance of coated micromolds for fabrication of microfluidic devices

Abstract

Micro-hot-embossing and micro-injection molding are potential plastic fabrication processes for mass production of microfluidic devices. However, both polymer substrate and micromold are receptive to structural damage due to high thermal stress, stiction and friction between the substrate and the mold. The tool life of an uncoated silicon (Si) micromold is very short but it has good fidelity. On the other hand, an uncoated stainless steel micromold can run for a long time without breakage but it’s lifetime in terms of the quality of polymer substrates produced is short. A major constraint for micromolds is their inability to withstand a prolonged sliding surface contact due to high sidewall friction or high cohesive energy. Thus, the surface of an ideal micromold should have low adhesion and friction along with high hardness and excellent wear resistance.