Title: Trapping microswimmers in acoustic streaming flow Show Chinese title

Title: 在声流场中捕获微泳者

Abstract: The acoustofluidic method holds great promise for manipulating microorganisms. When exposed to the steady vortex structures of acoustic streaming flow, these microorganisms exhibit intriguing dynamic behaviors, such as hydrodynamic trapping and aggregation. To uncover the mechanisms behind these behaviors, we investigate the swimming dynamics of both passive and active particles within a two-dimensional acoustic streaming flow. By employing a theoretically calculated streaming flow field, we demonstrate the existence of stable bounded orbits for particles. Additionally, we introduce rotational diffusion and examine the distribution of particles under varying flow strengths. Our findings reveal that active particles can laterally migrate across streamlines and become trapped in stable bounded orbits closer to the vortex center, whereas passive particles are confined to movement along the streamlines. We emphasize the influence of the flow field on the distribution and trapping of active particles, identifying a flow configuration that maximizes their aggregation. These insights contribute to the manipulation of microswimmers and the development of innovative biological microfluidic chips. Show Chinese abstract

Abstract: 声流控方法在操控微生物方面具有巨大潜力。 当暴露于声流稳态涡旋结构时，这些微生物表现出有趣的动态行为，例如水动力捕获和聚集。 为了揭示这些行为背后的机制，我们研究了二维声流场中被动粒子和活性粒子的游泳动力学。 通过采用理论计算的声流场，我们证明了粒子稳定有界轨道的存在。 此外，我们引入旋转扩散，并研究了不同流场强度下粒子的分布情况。 我们的研究发现，活性粒子可以在流线之间横向迁移，并被困在靠近漩涡中心的稳定有界轨道上，而被动粒子则被限制在沿流线运动。 我们强调流场对活性粒子分布和捕获的影响，确定了一种能最大化它们聚集的流场配置。 这些见解有助于微泳体的操控以及创新生物微流控芯片的发展。