The use of acoustic tweezers for precise manipulation of microparticles in the aqueous environment is essential and challenging for biomechanical applications in vivo. A 3-D acoustic tweezer is developed in this study for 3-D manipulation by using a two-dimensional (2-D) phased array consisting of 256 elements operating at 1.04 MHz. The emission phases of each element are iteratively determined by a backpropagation algorithm to generate multiple acoustic traps. Different traps are multiplexed in time, thus forming synthesized acoustic fields. We demonstrate the 3-D levitation and translation of positive acoustic contrast particles, a major class of bioparticles, in water by different acoustic traps, and compare the positional deviation along the intended path via experimentally measured trajectories. Improved manipulating stability was achieved by multiplexed acoustic traps. The 3-D acoustic tweezers proposed in this study provide a versatile approach of contactless bioparticle trapping and translation, paving the way toward future application of nanodroplet and microbubble manipulations.

中文翻译：

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3-D 声学镊子，使用带有时间复用陷阱的 2-D 矩阵阵列。

使用声学镊子对水环境中的微粒进行精确操作对于体内生物力学应用来说是必不可少且具有挑战性的。本研究开发了一种 3-D 声学镊子，通过使用由 256 个工作频率为 1.04 MHz 的二维 (2-D) 相控阵组成的二维 (2-D) 相控阵进行 3-D 操作。每个元素的发射相位由反向传播算法迭代确定，以生成多个声阱。不同的陷阱在时间上多路复用，从而形成合成声场。我们通过不同的声学陷阱演示了正声对比粒子（一类主要的生物粒子）在水中的 3-D 悬浮和平移，并通过实验测量的轨迹比较了沿预期路径的位置偏差。通过多路复用声阱实现了改进的操纵稳定性。本研究中提出的 3-D 声学镊子提供了一种非接触式生物粒子捕获和平移的通用方法，为纳米液滴和微泡操作的未来应用铺平了道路。