【作者】 刘莹；

【导师】 王敏杰； 宋满仓；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2012， 博士

【摘要】 随着微系统技术的快速发展,聚合物微结构制品在生物医学、环境工程、精密仪器、航空航天和信息通讯等领域得到越来越广泛的应用。聚合物微结构制品是指在常规尺寸制件上带有微结构特征的制品,如微流控芯片、微型传感器、微泵、微透镜阵列、导光板等。这些微结构制品的广泛和商业化应用得益于各种复制成型技术,其中注塑成型是其大批量、经济生产的有效手段。然而,微结构注塑成型面临多尺度的流动和传热问题,其质量控制较为复杂,特别是工艺参数选择,不但影响微结构特征的复制精度,还影响宏观基体的成型质量。本文结合“十一五”国家科技支撑计划项目(2006BAF04B13)中有关微流控芯片制造技术的研究内容,以微流控芯片注塑成型工艺过程为例,对该类微结构制品注塑成型的相关理论和关键技术进行了深入研究,具体内容如下：首先,以结构较为简单的单十字微通道微流控芯片作为研究对象,通过大量注塑成型试验,探索工艺参数影响芯片成型质量的影响规律,研究芯片制品缺陷的形成机理和改善途径；通过各工艺参数的单因素试验及正交试验,分析各工艺参数之间的交互影响程度,优化注塑成型过程的工艺控制方案,提出了减小乃至避免缺陷产生的工艺控制方案和技术。其次,通过数值模拟、理论分析及熔体流变特性试验、熔体填充可视化试验等,研究了熔体填充微结构型腔的流动行为。通过分析芯片制品微通道结构复制缺陷形成原因及缺陷程度,进一步明确微结构制品工艺参数选择的合理性,揭示了影响成型制品复制质量的内在机理,完善了微结构注塑成型工艺控制理论。其三,针对模具表面温度及温度分布对于微流控芯片成型质量的显著影响,以及微注塑成型设备及模具上的有限空间,研制并发明了一种基于热管传热和帕尔贴制冷技术的快速变温系统,设计制造了带有该快速变温系统的注塑模具,实现了模具表面快速变温和精确温度控制。其四,考虑到实际应用的微流控芯片具有复杂的微通道网络,以具有典型微流控芯片特征的双十字微通道芯片为模型,研究了由简单的单十字微流控芯片模型得到的工艺参数优化原则及适宜的工艺参数组合,在复杂微结构制品质量控制上的适用性；修正和完善了微结构制品注塑成型工艺参数控制标准。最后,在工艺控制优化研究成果的基础上,对不同尺寸、不同结构的微流控芯片,对微通道的复制精度进行了研究。研究结果表明,优化的工艺控制可以保证微通道结构的复制精度,在合理的工艺条件范围内,批量产品所复制的微通道具有一致性,且单个芯片内的微通道复制精度也具有一致性。研究表明,注塑成型技术可用于批量制造聚合物微流控芯片,具有很好的应用前景。更多还原

【Abstract】 With the rapid development of micro system technologies, micro structure parts are used widely in biomedical science, environmental engineering, precise instrument, aerospace, information communication and so on. Polymer micro structure parts are a kind of parts, which have the traditional dimension size with microstructure, such as microfluidic chip, microsensor, micro-pump, microlens array, light guide plate etc. Its extensive and commercial applications benefit from various replication technologies, which injection molding is the effective means to achieve mass and economical production. However, injection molding of micro structure parts needs to face many problems such as multi-scale flowing, heat transfer, etc. its quality control is quite complicated, especially the choice of process parameters, because it do not only influence the replication accuracy of microstructure, but also affect the molding quality of polymer parts. According to the demand of National Key Technologies Program of China (2006BAF04B13), the microfluidic chip is taken as an example to study the relative theory and key technology of microstructure parts molding thoroughly.Firstly, a kind of microfluidic chip with quite simple single-cross microchannel was chosen as research object. Through many molding experiments, the rules and mechanisms that how process parameters affected the chip molding qualities were analyzed, and the defects forming mechanisms for chip parts and the improving methods were studied. By means of single-factor and orthogonal experiments of each process parameter, the degree of interaction among parameter was analyzed, the process control towards injection molding was optimized, and then the process control solutions and technologies to reduce and even eliminate the defects were proposed.Secondly, based on numerical simulation, theoretical analysis, melt rheological experiments and visualized experiments of melt filling process, the mechanism and flow law during the melt filling to microstructure cavity were studied, the forming reasons of replication defects and defect levels in microchannel of chip parts were analyzed, and the reasonable principle of process parameters for parts with micro structure was gained and the mechanism of the influence on replication quality of molding parts was proposed, the process control theory on microstructure injection molding was improved.Thirdly, aimed at the significant effect of mold surface temperature and temperature distribution on molding qualities of microfluidic chips, and the finite space on the micro-injection machine and mold, a new kind of mold with heat pipe transfer and Peltier cooling device was studied and designed. Rapid heating and cooling, precise temperature control can be gained.Fourthly, considering the complicated microchannel network of microfluidic chips in practical application, a kind of microfluidic chip with double-cross microchannel was chosen to study the applicability of the rules on complicated microstfucture parts, which was obtained from simple single-cross microfluidic chip molding. The control standards of injection process parameters on micro structure was also modified and improved.Lastly, based on the experimental results of process control optimization, the replication accuracy of different microchannels of microfluidic chips was studied. The results showed that the optimized process control can guarantee the replication accuracy of microchannel structures. Within the reasonable range of process parameters, the microchannels replicated by batch production have consistency, moreover, microchannel replication accuracy of single chips also have consistency. Therefore, injection molding technology has the ability of successfully manufacturing microfluidic chips in mass and has promising prospect.更多还原