Brower Kara, White Adam K, Fordyce Polly M
Department of Bioengineering, Stanford University; Microfluidic Foundry, Stanford University; Chem-H Institute, Stanford University.
Department of Bioengineering, Stanford University; Microfluidic Foundry, Stanford University.
J Vis Exp. 2017 Jan 27(119):55276. doi: 10.3791/55276.
Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.
微流控系统为高通量生化和生物分析带来了强大的新方法。然而，对于那些能够从开发自己的微流控设备来解决研究问题中受益匪浅的非专业人士来说，进入这一领域仍然存在障碍。尤其缺乏的是与光刻相关协议的公开传播，而光刻是制造用于生产聚二甲基硅氧烷（PDMS）设备的复制模具的关键步骤。虽然文献中已经广泛探讨了单高度硅母版的制造，但对于许多有趣的设备功能（如使阀结构的特征变圆、多高度单模具图案化或高纵横比定义）所需的更复杂光刻特征的制造步骤，往往没有明确概述。在这里，我们提供了一个完整的协议，用于制造具有阀门和复杂多高度几何形状的多层微流控设备，可针对任何应用进行调整。这些制造程序是在微流控水凝胶珠合成器的背景下呈现的，并展示了含有聚乙二醇（聚乙二醇二丙烯酸酯）和光引发剂的液滴的产生，这些液滴可以聚合成固体珠子。该协议及相关讨论提供了设计原则和制造方法的基础，能够开发各种微流控设备。这里包含的细节应使非专业人士能够设计和制造新颖的设备，从而将一系列最近开发的技术应用于生物实验室中最令人兴奋的应用。
