Liu Zixing, Xu Guangyao, Ni Zhengyang, Chen Xizhou, Guo Xiasheng, Tu Juan, Zhang Dong
Key Laboratory of Modern Acoustics (MOE), School of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China.
Key Laboratory of Modern Acoustics (MOE), School of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China and The State Key Laboratory of Acoustics, Chinese Academy of Science, Beijing 100190, China.
Phys Rev E. 2021 Mar;103(3-1):033104. doi: 10.1103/PhysRevE.103.033104.
Acousotophoretic particle separations in counterpropagating surface acoustic wave (SAW) fields, e.g., standing SAWs (SSAWs), phase modulated SSAWs, tilted angle SSAWs, and partial standing SAWs, have proven successful. But there still lacks analytical tools for predicting the particle trajectory and optimizing the device designs. Here, we study the acoustophoresis of spherical Rayleigh particles in counterpropagating SAW fields and find that particle motions can be characterized into two distinct modes, the drift mode and the locked mode. Through theoretical studies, we provide analytical expressions of particle trajectories in different fields and different moving patterns. Based on these, we obtain theory-based protocols for designing such SAW acoustofluidic particle separation chips, which are demonstrated through finite-element simulations. The results here provide theoretical guidelines for designing high throughput and high efficiency particle separation devices.
在反向传播的表面声波（SAW）场中，例如驻波表面声波（SSAW）、相位调制SSAW、倾斜角SSAW和部分驻波表面声波中进行的声泳颗粒分离已被证明是成功的。但仍然缺乏用于预测颗粒轨迹和优化设备设计的分析工具。在这里，我们研究了反向传播SAW场中球形瑞利颗粒的声泳现象，发现颗粒运动可分为两种不同模式，即漂移模式和锁定模式。通过理论研究，我们给出了不同场和不同运动模式下颗粒轨迹的解析表达式。基于这些，我们获得了用于设计此类SAW声流控颗粒分离芯片的基于理论的方案，并通过有限元模拟进行了验证。这里的结果为设计高通量、高效率的颗粒分离设备提供了理论指导。
