Three dimensional acoustic tweezers with vortex streaming
Three dimensional acoustic tweezers with vortex streaming
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DOI：
10.1038/s42005-021-00617-0
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发表时间：
2021-06-03
影响因子：
5.5
通讯作者：
Cummer, Steven A.
中科院分区：
文献类型：
--
作者：
Li, Junfei;Crivoi, Alexandru;Cummer, Steven A.
声学镊子使用超声波对从毫米到亚微米尺度的颗粒进行无接触操作。粒子捕获通常与辐射力或声流场相关联。基于单光束聚焦声涡旋的声镊由于其选择性捕获能力而引起了相当大的关注，但已证明难以在没有复杂的换能器阵列和对被捕获颗粒性质的显著约束的情况下用于三维（3D）捕获。在这里，我们展示了一个3D声学镊子在流体中，使用一个单一的换能器，并结合了辐射力捕获在两个维度的流动力，以提供悬浮在第三个维度。在500kHz下操作的模拟和实验中证明了该想法，并且所实现的悬浮力比先前的3D捕获大三个数量级。这种集成了声流的混合声镊为该方法增加了额外的扭曲，并扩大了可以操纵的颗粒范围。虽然声学和光学镊子被广泛使用，但用简单的设置创建3D陷阱是具有挑战性的。在这里，声涡流与辐射力相结合，以实现流体中颗粒的3D捕获。
Acoustic tweezers use ultrasound for contact-free manipulation of particles from millimeter to sub-micrometer scale. Particle trapping is usually associated with either radiation forces or acoustic streaming fields. Acoustic tweezers based on single-beam focused acoustic vortices have attracted considerable attention due to their selective trapping capability, but have proven difficult to use for three-dimensional (3D) trapping without a complex transducer array and significant constraints on the trapped particle properties. Here we demonstrate a 3D acoustic tweezer in fluids that uses a single transducer and combines the radiation force for trapping in two dimensions with the streaming force to provide levitation in the third dimension. The idea is demonstrated in both simulation and experiments operating at 500kHz, and the achieved levitation force reaches three orders of magnitude larger than for previous 3D trapping. This hybrid acoustic tweezer that integrates acoustic streaming adds an additional twist to the approach and expands the range of particles that can be manipulated. Although acoustic and optical tweezers are widely used, it is challenging to create a 3D trap with a simple set-up. Here, acoustic vortex streaming is combined with radiation force to realise 3D trapping of particles in a fluid.