Although microfluidic micro-electromechanical systems (MEMS) are well suited to investigate the effects of mechanical force on large populations of cells, their high-throughput capabilities cannot be fully leveraged without optimizing the experimental conditions of the fluid and particles flowing through them. Parameters such as flow velocity and particle size are known to affect the trajectories of particles in microfluidic systems and have been studied extensively, but the effects of temperature and buffer viscosity are not as well understood. In this paper, we explored the effects of these parameters on the timing of our own cell-impact device, the μHammer, by first tracking the velocity of polystyrene beads through the device and then visualizing the impact of these beads. Through these assays, we find that the timing of our device is sensitive to changes in the ratio of inertial forces to viscous forces that particles experience while traveling through the device. This sensitivity provides a set of parameters that can serve as a robust framework for optimizing device performance under various experimental conditions, without requiring extensive geometric redesigns. Using these tools, we were able to achieve an effective throughput over 360 beads/s with our device, demonstrating the potential of this framework to improve the consistency of microfluidic systems that rely on precise particle trajectories and timing.

中文翻译：

---

惯性流聚焦：通过微流体MEMS器件为时序关键型应用优化细胞轨迹的案例研究。

尽管微流体微机电系统（MEMS）非常适合研究机械力对大量细胞的影响，但如果不优化流体和流过它们的实验条件，就无法充分利用其高通量能力。已知诸如流速和粒度之类的参数会影响微流体系统中颗粒的轨迹，并且已经进行了广泛的研究，但是对温度和缓冲液粘度的影响知之甚少。在本文中，我们首先跟踪了聚苯乙烯珠粒穿过该装置的速度，然后可视化了这些珠粒的影响，从而探索了这些参数对我们自己的细胞碰撞装置μHammer的计时的影响。通过这些检测，我们发现，设备的时机对粒子在通过设备时所经历的惯性力与粘性力之比的变化很敏感。这种灵敏度提供了一组参数，可以用作在各种实验条件下优化器件性能的强大框架，而无需进行大量的几何重新设计。使用这些工具，我们能够使用我们的设备实现超过360珠/秒的有效吞吐率，证明了该框架有潜力提高依赖于精确粒子轨迹和时间的微流体系统的一致性。这种灵敏度提供了一组参数，可以用作在各种实验条件下优化设备性能的强大框架，而无需进行大量的几何重新设计。使用这些工具，我们能够使用我们的设备实现超过360珠/秒的有效吞吐率，证明了该框架有潜力提高依赖于精确粒子轨迹和时间的微流体系统的一致性。这种灵敏度提供了一组参数，可以用作在各种实验条件下优化器件性能的强大框架，而无需进行大量的几何重新设计。使用这些工具，我们能够使用我们的设备实现超过360珠/秒的有效吞吐率，证明了该框架有潜力提高依赖于精确粒子轨迹和时间的微流体系统的一致性。