注射成型微流控芯片微沟槽成型质量的无损检测

Non-destructive testing for micro grooves of injection molded micro-fluidic chips

针对注射成型的微流控芯片具有微沟槽深度成型质量好,宽度成型质量较差,而且各处微沟槽的宽度成型质量不均衡的特点,利用Matlab软件的图像处理工具箱开发了微流控芯片微沟槽显微平面图片的图像处理系统,实现了利用常用的光学显微镜对微沟槽的成型质量进行无损检测。引入人工干涉来进行高效图像去噪处理。根据提取的微结构轮廓点进行了微沟槽轮廓的曲线拟合,测量了微沟槽的开口宽度和底部宽度。对由微流控芯片微沟槽显微平面图片所得到的测量结果与由对微流控芯片进行切片检测所得到的测量结果进行比较,结果显示,两种方法得到的微沟槽开口宽度相差约4%,槽底部宽度相差约3%,说明微沟槽显微平面图片的测量结果能够满足注射成型工艺研究中微流控芯片微结构成型质量检测的要求。

Injection molded micro-fluidic chips are characterized by that their micro grooves show perfect imaging quality in height but not satisfactory in width,meanwhile the chip cannot remain the uniform quality for the width of micro groove everywhere.Therefore,this paper proposes an image processing system based on Matlab to process the micro flat photo of the micro groove of an injection molded micro-fluidic chip and to complete the non-destructive testing for the micro groove.In image processing,the artificial interference is introduced to eliminate the image noise effectively and the profile point extracted form the photo are used to fit the profile lines of the groove.Then,the opening width and bottom width of the micro groove are measured.Measured data of microchannel widths from the micro flat photos are compared with those data obtained from cross-sectional photos of microchannel slices.Results indicate that the differences between the two measuring ways are less than 4% for the opening width and less than 3% for the bottom width,respectively.Obtained data demonstrate that the proposed non-destructive method based optical telescope can meet the requirements of micro-fluidic chips for measurement of molded quality in injection molding.