Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, 08826, Republic of Korea.
Lab Chip. 2018 Jul 10;18(14):2013-2022. doi: 10.1039/c7lc01288h.
Liquid patterning is a quintessential aspect in cell-based screening. While there are a variety of methods to handle microliquids utilizing surface treatments, complex microfluidic systems, and automated dispensing, most of the stated methods are both expensive and difficult to implement. Here, we present a fast multi-scale microliquid-patterning method on an open surface using embossed microstructures without surface modification. Arrays of micropillars can trap microliquids when a bulk drop is swept by an elastic sweeper on polystyrene (PS) substrates. The patterning mechanism on a basic form of a 2 × 2 rectangular array of circular pillars is analyzed theoretically and verified with experiments. Nanoliter-to-microliter volumes of liquids are patterned into various shapes by arranging the pillars based on the analysis. Furthermore, an array of geometrically modified pillars can capture approximately 8000 droplets on a large substrate (55 mm × 55 mm) in one step. Given the simplistic method of wipe patterning, the proposed platform can be utilized in both manual benchtop and automated settings. We will provide proof of concept experiments of single colony isolation using nanoliter-scale liquid patterning and of human angiogenic vessel formation using sequential patterning of microliter-scale liquids.
液滴图案化是基于细胞筛选的一个重要方面。虽然有多种方法可以利用表面处理、复杂的微流控系统和自动化分配来处理微液滴，但大多数所述方法既昂贵又难以实施。在这里，我们提出了一种快速的多尺度微液滴图案化方法，即在没有表面修饰的情况下，使用压印微结构在开放表面上进行。当大量液滴被聚苯乙烯（PS）基底上的弹性清扫器扫过时，阵列微柱可以捕获微液滴。对基本形式的 2×2 圆形微柱矩形阵列的图案化机制进行了理论分析，并通过实验进行了验证。通过根据分析排列微柱，可以将纳升到微升体积的液体图案化为各种形状。此外，通过排列几何形状修改后的微柱阵列，可以在一个步骤中在大基底（55mm×55mm）上捕获大约 8000 个液滴。鉴于擦拭图案化的简单方法，所提出的平台可用于手动台式和自动化设置。我们将提供使用纳升级液体图案化进行单个菌落分离的概念验证实验，以及使用微升级液体的顺序图案化进行人血管生成血管形成的实验。
