School of Engineering, University of Glasgow, Glasgow, UK.
IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Oct;58(10):2132-8. doi: 10.1109/TUFFC.2011.2062.
An acoustic particle manipulation system is presented, using a flexible printed circuit board formed into a regular heptagon. It is operated at 4 MHz and has a side dimension of 10 mm. The heptagonal geometry was selected for its asymmetry, which tends to reduce standing wave behavior. This leads to the possibility of having fine control over the acoustic field by varying the output phases of the transducer elements. Configurations with two and three active transducers are demonstrated experimentally. It is shown that with two transducers, the particles align along straight lines, the position of which can be moved by varying the relative excitation phases of the two transducers. With three active transducers, hexagonal-shaped patterns are obtained that can also be moved, again according to the phase of the excitation signals. Huygens' principle-based simulations were used to investigate the resultant pressure distributions. Good agreement was achieved between these simulations and both Schlieren imaging and particle manipulation observations.
提出了一种使用柔性印刷电路板形成规则七边形的声粒子操纵系统。它在 4MHz 下工作，边长为 10mm。选择七边形几何形状是因为其不对称性，这有助于减少驻波行为。这使得通过改变换能器元件的输出相位来精细控制声场成为可能。实验演示了具有两个和三个有源换能器的配置。结果表明，使用两个换能器，粒子沿着直线排列，通过改变两个换能器的相对激励相位，可以移动这些直线的位置。使用三个有源换能器，可以获得也可以根据激励信号的相位移动的六边形图案。基于惠更斯原理的模拟用于研究所得的压力分布。这些模拟与纹影成像和粒子操纵观察结果之间取得了良好的一致性。
