应用超声分离微纳米颗粒的微型装置的设计与微制造

Design and fabrication of microdevice for microparticles ultrasonic separation

本文在对一种新的应用超声分离微纳米颗粒的微型装置进行设计并完成其微制造过程的基础上,分析了装置特性,重点研究了运用此装置进行微纳米颗粒分离时微粒的受力情况。文中首先给出了微粒在流体中受力的一维解析模型,讨论了影响作用于微粒的超声辐射力的因素,并通过有限元方法软件ANSYS对微型超声装置的振动模式及共振频率进行了研究,分析了微粒分离时装置中的声场与流场。在这些分析的基础上,计算得出了微型装置在不同工作模式下处于不同介质中的多种微粒的受力情况。

A new MEMS device that can separate microparticles on - chip by the use of bulk - mode excited membrane vibration is designed and microfabricated. The performance of the microdevice is studied in detail, especially the force for separating particles in the microdevice. Starting from the one - dimensional analytical mode of the acoustic radiation force, we study the factors affecting particles separation within the liquid medium. Then, finite element method in ANSYS is used to analyze the vibration modes of the microdevice, the acoustic field and flow field in the microdevice due to the membrane vibration. With these analyses, we obtain the forces acting on different particles in the water, blood plasma and milk medium when the microdevice vibrates at different frequencies.