Study Of Injection Molding Visualization For Microfluidic Chip And Micro Image Processing

Micro chip lab is considered as the most advanced technology in 21st century for its excellent merits. Micro injection molding is most appropriate for commercial production of microfluidic chips owing to its high productivity. However, the processing parameters have not been matured. How to improve the quality of injection molded microfliudic chips absorbs many researchers' interest. Visualization of the micro injection molding can offer a great help for finding out the cause of injection molding quality defects and optimizing injection molding process. Fundamental study of injection molding visualization for the microfluidic chip is carried out in this paper, including design of the visual mold, development of the micro image processing system for 3D reconstructing and dimensional measuring of the micro groove's planar picture.Firstly, previous researches on micro injection molding and visual mold are summarized. Factors which strongly influence the plastic part's quality include the plastic material's performance, the mold temperature, the injection speed and the injection pressure. Sum-up of the former visual molds provides useful reference for this paper's visual mold design.Secondly, based on analysis of the key points for micro injection mold design and visualization mold design, the mold for visualization of microfluidic chip's injection molding is designed.Thirdly, filling process of the visual mold's cavity is simulated by using Moldflow software, and the mechanical behavior of the quartz glass window is simulated by using Ansys software. Simulating results show that the quartz glass shaft will prolong the cavity filling stage and raise the injection pressure requirement, and the quartz glass shaft will not be destroyed under practical molding condition.Finally, the micro groove's planar picturea are collected, and the micro image processing system is developed based on Matlab software. The system contains micro grove width measuring part and micro grove shape showing part. By comparing the measuring data of 3D reconstructing for a micro planar picture with the measuring data of a factual cross section picture coming from cutting the micro groove, measuring errors of the micro groove's width is 2%, which indicates that this image processing system can satisfy the primary quality checking of the injection molded microfluidic chip.