Microfluidic Control Chip Injection Molding Process Parameters Optimization

At present, microfluidic chip is one of the hottest areas in MEMS field. Polymers with certain advantages of perfect biocompatible properties, good surface properties and low fluorescence background, as well as easy processing, normally low cost and easy to mass production, which make most of the bio and chemical analysis can be successfully performed, have draw great attention. In this paper, the main research was the design and manufacture of the injection mold, and the influence of processing parameters on the warpage and cross-sectional appearance, aiming at achieving the low cost and mass production of microfluidic chip.Firstly, microfluidic chip was designed as the model of three channels(100μm in width, 40μm in height).A nickel mold insert was made using UV-LIGA process. The experimental mold was designed and manufactured, which provided an experiment platform for the research og micro injection molding and development of plastic microfluidic chip.According to the mechanism of the bonding of microfluidic chip and the analysis of the theory of injection molding, it was to optimize the processing parameters that chosing the warpage of the part as the aim of the simulation. Using Moldflow MPI, the influence of mold temperature, melt temperature, injection speed, holding pressure, holding time and cooling time on warpage of microfluidic chip were predicted, and the optimized parameters were got, in which holding pressure and holding time were the most influence on the warpage, melt temperature and injection speed were the least influence.Basing on the principle of electrophoresis and the application request of microfluidic chip, it was to optimize the processing parameters that chosing the appearance change of the part as the aim of the simulation. On the base of the research of the predecessor in micro-injection, we could conclude that the mold temperature, melt temperature and injection speed were the most influence on the molding of the micro-structure. Basing the optimized result of the simulation, the best assemble of the processing parameters were obtained in signal factor experiment, which were concluded through detecting the changing of the cross-sectional appearance by the image measuring apparatus.In this paper, by means of the research of the simulation and experiment, we got the optimized processing parameters in the injection molding, which ensured the minimum of the warpage as well as decreased the change of the cross-sectional appearance.