Hovering Microswimmers Exhibit Ultrafast Motion to Navigate under Acoustic Forces
Hovering Microswimmers Exhibit Ultrafast Motion to Navigate under Acoustic Forces
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DOI：
10.1002/admi.201800425
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发表时间：
2018-08-23
影响因子：
5.4
通讯作者：
Marmottant, Philippe
中科院分区：
文献类型：
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作者：
Louf, Jean-Francois;Bertin, Nicolas;Marmottant, Philippe
本研究的目标是设计包含气泡的3D微型游泳者，该气泡可以用换能器发射的声波进行刺激和引导。通过使用3D微制造技术，20 x 20 x 26 μ m的游泳者被设计成具有指向基底的捕获气泡，从而模仿气垫船。声振动然后被远程地施加到气泡，其产生强的稳定流（0.1-2 mm s（-1）），这种效应被称为声流，导致气垫船下方的射流。研究发现，游泳者的运动依赖于两个参数，即声波的频率和振幅。测量了游泳者的速度，观察到一个非常宽的分布，从0.05到350 mm s（-1）或17500个体长。如此高的速度在身体长度方面使这个游泳者在文献中报道的不同的微型游泳者中最快的一个。游泳者的运动被认为是两个力的组合，在不同的方向取向：流动力和辐射力。第一个是减少附着力，第二个是帮助运动。使用朝向不同方向定向的不同换能器，游泳者也能够被导航到不同方向。
The goal of this study is to engineer 3D-microswimmers containing a bubble that can be stimulated and guided with acoustic waves emitted by transducers. By using 3D-microfabrication techniques, 20 x 20 x 26 mu m swimmers are designed with a trapped air bubble pointing toward the substrate, thus mimicking a hovercraft. Acoustic vibrations are then remotely applied to the bubble, which generates a strong steady flow (0.1-2 mm s(-1)), an effect referred as acoustic streaming, resulting in a jet below the hovercraft. It is found that the motion of the swimmer relies on two parameters, namely the frequency and amplitude of the acoustic wave. The swimmer velocities are measured and a very wide distribution from 0.05 to 350 mm s(-1) or 17 500 body lengths is observed. Such a high velocity in terms of body length makes this swimmer one of the fastest among the different microswimmers reported in the literature. The motion of the swimmer is found to be a combination of two forces orientated in different directions: the streaming force and the radiation force. While the first one is reducing adhesion, the second one is helping the motion. Using different transducers orientated toward different directions, the swimmer is enabled to be navigated into different directions as well.