Bubbles locating in microfluidic chamber can produce acoustic streaming vortices by applying travelling surface acoustic wave oscillation in an ultrasonic range, which can be used to drive bio-samples to move within the flow field. In this paper, a strategy of bubble array configured in a large number of regularly arranged horseshoe structures is proposed to capture and rotate cells simultaneously. By modifying the geometric parameters of the horseshoe structure and microfluidic setting, high bubble homogeneity and cell trapping percentage was achieved. The simulation and experimental results of the bubble-induced streaming vortices were confirmed to be consistent. Through experiments, we achieved both in-plane and out-of-plane rotation of arrayed HeLa cells trapped by the bubbles. Out-of-plane rotation was used to reconstruct the 3D (three-dimensional) cell morphology, which was demonstrated to be useful in calculating cell geometry related parameters. We believe that this bubble array based cell rotation method is expected to be a promising tool for the investigation of bioengineering, biophysics, medicine, and cell biology.

中文翻译：

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声振荡气泡阵列在片上同时旋转大规模细胞

通过在超声范围内施加传播的表面声波振荡，位于微流体腔室中的气泡可产生声流涡流，可用于驱动生物样本在流场内移动。本文提出了一种在大量规则排列的马蹄形结构中配置气泡阵列的策略，以同时捕获和旋转细胞。通过修改马蹄结构的几何参数和微流体设置，可以实现较高的气泡均质性和细胞捕获率。气泡引起的流涡的模拟和实验结果被证实是一致的。通过实验，我们实现了气泡捕获的阵列HeLa细胞的面内和面外旋转。平面外旋转用于重建3D（三维）细胞形态，这被证明可用于计算与细胞几何相关的参数。我们认为，这种基于气泡阵列的细胞旋转方法有望成为研究生物工程，生物物理学，医学和细胞生物学的有前途的工具。