Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland, USA.
Lab Chip. 2017 Oct 25;17(21):3717-3724. doi: 10.1039/c7lc00910k.
An innovative platform enabling complex discretization and manipulation of aqueous droplets is described. The system uses simple membrane displacement trap elements to perform multiple functions including droplet discretization, release, metering, capture, and merging. Multi-layer PDMS devices with membrane displacement trap arrays are used to discretize sample into nanoliter scale droplet volumes, and reliably manipulate individual droplets within the arrays. Performance is characterized for varying capillary number flows, membrane actuation pressures, trap and membrane geometries, and trapped droplet volumes, with operational domains established for each platform function. The novel approach to sample digitization and droplet manipulation is demonstrated through discretization of a dilute bacteria sample, metering of individual traps to generate droplets containing single bacteria, and merging of the resulting droplets to pair the selected bacteria within a single droplet.
描述了一种能够对水相液滴进行复杂离散化和操作的创新平台。该系统使用简单的膜置换捕获元件来执行多种功能，包括液滴离散化、释放、计量、捕获和合并。采用具有膜置换捕获元件阵列的多层 PDMS 器件将样品离散化为纳升级别的液滴体积，并可靠地在阵列内操纵各个液滴。针对不同的毛细数流动、膜致动压力、捕获和膜几何形状以及捕获液滴体积对性能进行了特征描述，为每个平台功能建立了操作域。通过对稀释细菌样品的离散化、对单个捕获器进行计量以生成含有单个细菌的液滴，以及合并得到的液滴以将选定的细菌配对到单个液滴内，展示了这种新颖的样品数字化和液滴操作方法。
