Imaging flow cytometry is a powerful tool by virtue of its capability for high‐throughput cell analysis. The advent of high‐speed optical imaging methods on a microfluidic platform has significantly improved cell throughput and brought many degrees of freedom to instrumentation and applications over the last decade, but it also poses a predicament on microfluidic chips. Specifically, as the throughput increases, the flow speed also increases (currently reaching 10 m/s): consequently, the increased hydrodynamic pressure on the microfluidic chip deforms the wall of the microchannel and produces detrimental effects lead to defocused and blur image. Here, we present a comprehensive study of the effects of flow‐induced microfluidic chip wall deformation on imaging flow cytometry. We fabricated three types of microfluidic chips with the same geometry and different degrees of stiffness made of polydimethylsiloxane (PDMS) and glass to investigate material influence on image quality. First, we found the maximum deformation of a PDMS microchannel was >60 μm at a pressure of 0.6 MPa, while no appreciable deformation was identified in a glass microchannel at the same pressure. Second, we found the deviation of lag time that indicating velocity difference of migrating microbeads due to the deformation of the microchannel was 29.3 ms in a PDMS microchannel and 14.9 ms in a glass microchannel. Third, the glass microchannel focused cells into a slightly narrower stream in the X‐Y plane and a significantly narrower stream in the Z‐axis direction (focusing percentages were increased 30%, 32%, and 5.7% in the glass channel at flow velocities of 0.5, 1.5, and 3 m/s, respectively), and the glass microchannel showed stabler equilibrium positions of focused cells regardless of flow velocity. Finally, we achieved the world's fastest imaging flow cytometry by combining a glass microfluidic device with an optofluidic time‐stretch microscopy imaging technique at a flow velocity of 25 m/s. © 2019 International Society for Advancement of Cytometry

中文翻译：

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流动诱导微流控芯片壁变形对成像流式细胞术的影响。

成像流式细胞术是一种强大的工具，因为它具有高通量细胞分析的能力。在过去十年中，微流控平台上高速光学成像方法的出现显着提高了细胞通量，并为仪器和应用带来了许多自由度，但它也给微流控芯片带来了困境。具体来说，随着吞吐量的增加，流速也会增加（目前达到 10 m/s）：因此，微流控芯片上增加的流体动压力使微通道壁变形并产生不利影响，导致图像散焦和模糊。在这里，我们全面研究了流动诱导的微流控芯片壁变形对成像流式细胞术的影响。我们制造了由聚二甲基硅氧烷 (PDMS) 和玻璃制成的三种具有相同几何形状和不同刚度的微流控芯片，以研究材料对图像质量的影响。首先，我们发现在 0.6 MPa 的压力下，PDMS 微通道的最大变形 >60 μm，而在相同压力下，在玻璃微通道中没有发现明显的变形。其次，我们发现由于微通道变形导致微珠迁移速度差异的滞后时间偏差在 PDMS 微通道中为 29.3 ms，在玻璃微通道中为 14.9 ms。第三，玻璃微通道将细胞聚焦成 X-Y 平面上略窄的流和 Z 轴方向上明显更窄的流（聚焦百分比增加了 30%、32% 和 5. 7% 在玻璃通道中，流速分别为 0.5、1.5 和 3 m/s），并且玻璃微通道显示出更稳定的聚焦细胞平衡位置，而不管流速如何。最后，我们通过将玻璃微流体装置与光流体时间拉伸显微镜成像技术相结合，以 25 m/s 的流速实现了世界上最快的成像流式细胞术。© 2019 国际细胞计量学促进会