Surface acoustic waves (SAWs) generated in a piezoelectric substrate couple with a liquid according to Snell's law such that a compressional acoustic wave propagates obliquely at a Rayleigh angle ( θ t) inside the microchannel to form a region devoid of a direct acoustic field, which is termed a microchannel anechoic corner (MAC). In the present study, we used microchannels with various heights and widths to characterize the width of the MAC region formed by a single travelling SAW. The attenuation of high-frequency SAWs produced a strong acoustic streaming flow that moved the particles in and out of the MAC region, whereas reflections of the acoustic waves within the microchannel resulted in standing acoustic waves that trapped particles at acoustic pressure nodes located within or outside of the MAC region. A range of actuation frequencies and particle diameters were used to investigate the effects of the acoustic streaming flow and the direct acoustic radiation forces by the travelling as well as stand...

中文翻译：

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由表面声波形成的微通道消声角的表征

根据斯涅耳定律，压电基板中产生的表面声波 (SAW) 与液体耦合，使得压缩声波在微通道内以瑞利角 (θt) 倾斜传播，形成一个没有直接声场的区域，称为微通道消声角 (MAC)。在本研究中，我们使用具有不同高度和宽度的微通道来表征由单个行进 SAW 形成的 MAC 区域的宽度。高频声表面波的衰减产生了强大的声流流动，将粒子移入和移出 MAC 区域，而微通道内的声波反射导致驻声波，将粒子捕获在位于内部或外部的声压节点处MAC 区域。