For better understanding and optimization of multiphase flow in miniaturized devices, micro‐computed tomography (μCT) is a promising visualization tool, as it is nondestructive, three‐dimensional, and offers a high spatial resolution. Today, computed tomography (CT) is a standard imaging technique. However, using CT in microfluidics is still challenging, since X‐ray related artifacts, low phase contrast, and limited spatial resolution complicate the exact localization of interfaces. We apply μCT for the characterization of stationary interfaces in thin capillaries. The entire workflow for imaging stationary interfaces in capillaries, from image acquisition to the analysis of interfaces, is presented. Special emphasis is given to an in‐house developed segmentation routine. For demonstration purposes, contact angles of water, liquid polydimethylsiloxane, and air in FEP, glass, and PMMA are determined and the influence of gravity on interface formation is discussed. This work comprises the first steps for a systematic 3D investigation of multiphase flows in capillaries using μCT.

中文翻译：

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显微计算机断层扫描技术，用于研究毛细管中固定的液-液和液-气界面

为了更好地理解和优化小型设备中的多相流，微计算机断层扫描（μCT）是一种很有前途的可视化工具，因为它是无损的，三维的，并且具有很高的空间分辨率。如今，计算机断层扫描（CT）是一种标准的成像技术。但是，在微流体中使用CT仍然具有挑战性，因为与X射线相关的伪像，低相衬度和有限的空间分辨率使界面的精确定位变得复杂。我们将μCT用于薄毛细管中固定界面的表征。介绍了用于毛细管中固定接口成像的整个工作流程，从图像采集到接口分析。内部开发的细分例程特别受重视。为了演示的目的，水的接触角 确定了液态聚二甲基硅氧烷，FEP，玻璃和PMMA中的空气，并讨论了重力对​​界面形成的影响。这项工作包括使用μCT对毛细管中多相流进行系统3D研究的第一步。