Two-dimensional acoustic focusing of microparticles in a rectangular microchannel using a dual-frequency-excited single transducer
Two-dimensional acoustic focusing of microparticles in a rectangular microchannel using a dual-frequency-excited single transducer
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DOI：
10.1016/j.snb.2022.133127
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Tatsuki Jonai;Y. Akiyama
中科院分区：
文献类型：
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作者：
Tatsuki Jonai;Y. Akiyama
二维聚焦可以极大地提高粒子富集系统的效率，但由于所需的二维聚焦设备的复杂性，其尚未得到广泛应用。传统的二维聚焦设备包括两个独立的振动系统，工作在不同的频率。与此相反，本文提出了一种通过同时在双频下激励PZT来实现二维聚焦的方法。这是通过使用单一振动系统并将预组合信号输入到高频功率放大器来完成的。首先，在宽高比为2的矩形微通道中，实验证实了50µm微粒的二维聚焦。其次，对二维聚焦过程中的激励信号和振动状态进行了时域和频域分析。然后，通过水平聚焦和垂直聚焦叠加的方法，进行了二维聚焦的数值模拟。还证实了二维聚焦大大提高了富集系数，使其与传统的二维聚焦相当。在此基础上，对不同尺寸的微粒子进行了二维聚焦实验和数值模拟。最后，在长宽比分别为1.3和2.6的矩形微通道中确认了二维聚焦。结果表明，无论长宽比如何，二维聚焦方法都适用于各种尺寸的微粒。结果表明，该方法可以很容易地应用于大多数传统声学系统，并能提高它们的效率。
The 2D focusing can drastically improve the efficiency of particle enrichment systems, but it has not been widely used due to the complexity of the required 2D focusing equipment. The conventional 2D focusing equipment includes two independent vibration systems operating at different frequencies. In contrast, a method is proposed here that can perform 2D focusing by simply exciting the PZT at dual frequencies simultaneously. This is done using a single vibration system and inputting the pre-combined signals to a high-frequency power amplifier. First, the 2D focusing of 50-µm microparticles was experimentally confirmed in a rectangular microchannel with the aspect ratio of 2. Next, the excitation signals and the vibration state in 2D focusing were analyzed in the time domain and the frequency domain. Then, a numerical simulation was done that reproduced the 2D focusing by superposition of horizontal and vertical focusing. It was also confirmed that the 2D focusing drastically improved the enrichment factor, making it equal to that of the conventional 2D focusing. Then, 2D focusing of various-sized microparticles were attempted experimentally and numerically. Finally, the 2D focusing was confirmed in the rectangular microchannels with different aspect ratios of 1.3 and 2.6. The results suggested the 2D focusing method was applicable for wide-ranging sizes of microparticles regardless of the aspect ratio. It was concluded that the method could be easily applied to most conventional acoustic systems and it was able to improve their efficiency.