Manipulation of particles in two dimensions using phase controllable ultrasonic standing waves
Manipulation of particles in two dimensions using phase controllable ultrasonic standing waves
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DOI：
10.1098/rspa.2011.0269
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发表时间：
2012-02-08
影响因子：
3.5
通讯作者：
Cumming, D. R. S.
中科院分区：
文献类型：
--
作者：
Courtney, C. R. P.;Ong, C. -K.;Cumming, D. R. S.
在流体中操纵致密微米级物体的能力是生物科学感兴趣的，目的是改进分析技术和实现组织工程。提出并论证了一种捕获微米级粒子并在二维平面上操纵它们的方法。相位控制反向传播波用于产生具有任意节点位置的超声驻波。声辐射力将致密颗粒驱动到压力节点。它示出解析，一系列的点状陷阱可以产生在一个二维平面中使用两个正交对反向传播波。这些陷阱可以通过适当调整相对相位来操纵。四个5 MHz的换能器（设计用于最大限度地减少反射）被用作充水腔中反向传播波的源。捕获并操作直径为10 μ m的聚苯乙烯珠粒。被困粒子的位置和四个换能器的相对相位之间的关系进行测量，并示出同意解析推导的表达式。通过确定对场的突然变化的响应来测量可用的力，并且发现对于30 V-pp输入，可用的力为30 pN，这与系统模型的预测一致。一个可扩展的制造方法来生产设备的证明。
The ability to manipulate dense micrometre-scale objects in fluids is of interest to biosciences with a view to improving analysis techniques and enabling tissue engineering. A method of trapping micrometre-scale particles and manipulating them on a two-dimensional plane is proposed and demonstrated. Phase-controlled counter-propagating waves are used to generate ultrasonic standing waves with arbitrary nodal positions. The acoustic radiation force drives dense particles to pressure nodes. It is shown analytically that a series of point-like traps can be produced in a two-dimensional plane using two orthogonal pairs of counter-propagating waves. These traps can be manipulated by appropriate adjustment of the relative phases. Four 5MHz transducers (designed to minimize reflection) are used as sources of counter-propagating waves in a water-filled cavity. Polystyrene beads of 10 mu m diameter are trapped and manipulated. The relationship between trapped particle positions and the relative phases of the four transducers is measured and shown to agree with analytically derived expressions. The force available is measured by determining the response to a sudden change in field and found to be 30 pN, for a 30 V-pp input, which is in agreement with the predictions of models of the system. A scalable fabrication approach to producing devices is demonstrated.