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.

中文翻译：

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在开放表面上进行微结构引导的多尺度液体构图†

液体图案化是基于细胞的筛选中的一个典型方面。尽管存在多种利用表面处理，复杂的微流体系统和自动分配来处理微液体的方法，但大多数所述方法既昂贵又难以实施。在这里，我们提出了一种在表面不使用表面修饰的压纹微结构的快速多尺度微液体构图方法。当用弹性清扫器将大量液滴扫到聚苯乙烯（PS）基材上时，微柱阵列会捕获微液体。从理论上分析了2×2圆形圆柱矩形阵列基本形式上的图案形成机理，并通过实验进行了验证。通过在分析的基础上排列柱子，可以将纳升至微升体积的液体构图为各种形状。此外，一组经过几何修饰的柱子可以一步一步捕获大基材（55 mm×55 mm）上的大约8000个液滴。鉴于擦拭图案的简化方法，建议的平台可用于手动台式和自动设置。我们将提供使用纳升规模的液体图案进行单菌落分离和使用微升规模的液体进行顺序图案进行人血管生成血管形成的概念实验的证据证明。