Manipulation by focused ultrasound is an emerging technology with much promise for non-contact handling of microscale objects. A particularly promising approach for achieving this with living cells involves incorporating standing surface acoustic waves (SSAWs) into a microfluidic device. SSAWs must be tuned to provide the necessary range of acoustic radiation force (ARF), but models enabling this tuning have neglected the mechanics of the cells themselves, treating cells as rigid or homogenous spheres, and have also neglected energy transfer from the substrate to the fluid at the Rayleigh angle. We therefore applied Mie scattering theory to develop a model of the ARF arising from a SSAW impacting an idealized eukaryotic cell in an inviscid fluid. The cell was treated as a three-layered body with a nucleus, cytoplasm, and cortical layer. Results showed strong dependence on cell structures and the Rayleigh angle that can be harnessed to develop novel applications for cell manipulation and sorting. ARF can be tuned using the new model to both push away and pull back a cell towards the sound source. The proposed analytical model provides a foundation for design of microfluidic systems that manipulate and sort cells based upon their mechanical properties.

通过聚焦超声进行操纵是一种新兴技术，有望以非接触方式处理微尺度物体。用活细胞实现这一目标的一种特别有前途的方法涉及将驻表面声波（SSAW）合并到微流体设备中。必须对SSAW进行调整以提供必要的声辐射力（ARF）范围，但是启用该调整的模型忽略了电池本身的力学，将电池视为刚性或均质的球体，并且也忽略了从基板到表面的能量转移。瑞利角的流体。因此，我们应用Mie散射理论来开发由SSAW影响无粘性流体中理想化的真核细胞的ARF模型。将细胞视为具有核，细胞质和皮质层的三层体。结果显示出强烈依赖于细胞结构和瑞利角，可以利用它们来开发细胞操纵和分选的新应用。可以使用新模型对ARF进行调整，以将单元推向声源并向后拉。提出的分析模型为微流控系统的设计提供了基础，该系统可根据细胞的机械特性对其进行操作和分类。