Implementation and analysis of polymeric microstructure replication by micro injection molding

This paper presents the adaptation of a conventional injection molding process to the mass replication of polymeric microstructures with appropriate mold design and process control. Using wet-etched silicon wafers with microstructures on the surfaces as mold inserts, we have successfully predicted, improved and optimized the replication results. The flow behaviors of polymer melts in micro mold-cavities are characterized by both simulation and experiments. Among various process parameters, temperature is identified as the key factor that decisively determines the quality of injection-molded microstructures. Based on the collected experimental and simulation results, process optimization is performed to improve replication quality and to establish guidelines for potential applications. Because of its high speed and low cost, the adaptation of the injection molding process to microfabrication will lead to a promising technology for MEMS applications.