【作者】 尹执中；

【导师】 过增元；

【作者基本信息】 清华大学 ， 工程热物理， 1999， 博士

【摘要】 微流动系统作为微电子机械系统的一个重要领域，在医疗保健、环境监控、化学分析及生物工程中有巨大的市场前景。本论文对热驱动微型泵的丰要部件(驱动膜片和悬臂梁式微型阀)及微型泵的整体性能进行了较系统的理论分析、数值模拟和实验研究。 对驱动膜片的温度响应和振动特性进行了分析和模拟，得到了膜片的温度和振动的频率特性及随功率的变化。基于驱动膜片的温度响应和力的尺寸效应阐明了热驱动方式在微细尺度领域的可行性和优点。对膜片的结构参数进行了优化分析。铝膜形状取为圆形比环形有利于得到更大的泵腔变形容积；减薄硅膜厚度和增加铝膜的厚度也能增大泵腔容积变化量；加热区域位于膜片中央也比位于膜片外围有利于膜片产生更大变形。在此基础上提出了膜片的优化结构参数。 对悬臂梁式微型阀的启动、静态和动态过流特性进行了分析和模拟。得到了微型阀的启动压力和静态下阀的流量与压差的关系以及阀片的几何尺寸对阀的流量的影响。分析表明本文中的微型阀的固有频率比热驱动微型泵的工作频率高得多，因此阀片的动态特性可不予考虑。 通过数值模拟得到了泵的频率特性。泵的流量随加热频率变化有个峰值。在本文给定条件下，当频率为3.3Hz时，泵的流量达到最大(26.96μl／min)。在此基础上提出了泵的最佳工作频率范围。模拟了流量随进出口压差和加热功率的变化，当输入功率为1.0W时，零流量时的压头可达约64kPa。对膜片内有预应力存在和没有预应力时流量随加热功率的变化进行了比较，功率较低时，没有预应力存在时流量较大；而随着功率的增大，有预应力存在的泵的流量迅速增大并能大于没有预应力时的流量。此外，有预应力存在时，在一段功率范围内(如1.2-1.8W)，泵的流量与输入功率比最大。 对泵及其主要部件进行了实验和测试。用热像仪对驱动膜片的温度响应进行了测试，得到了不同加热功率和频率条件下膜片的温度响应曲线。用投影散斑数字相关方法对驱动膜片的振动进行了测试，得到了不同加热更多还原

【Abstract】 As a hot point in MEMS, microfuildics shows great market potential in the areas of medicine, chemical analysis, environmental detection and biological engineering, etc. In this thesis, performances of main parts of thermal actuated micropump and micropump itself are theoretically and numerically analyzed and experimentally tested.Temperature distribution and oscillation of the driving membrane of thermal actuated micropump are numerically analyzed at many cases with the driving frequency and input power as parameter. Based on the temperature distribution analysis and dimension effect of forces, Analysis indicates that thermal actuated pump is efficient only at small scale. Optimization of construction of the membrane shows that circular aluminum membrane is more advisable than annular one. The stroke volume of the chamber is enlarged when the thickness of aluminum membrane is increased or that of silicon membrane is decreased. Placing the polysilicon at the center is better than placing it at edge.The priming pressure, static and dynamic characteristics of cantilever microvalve are analyzed to obtain the relationship between geometrical size, static pressure difference and flow rate. Resonance frequency of the microvalve is much higher than the working frequency of the thermal actuated micropump. So the dynamic characteristics of cantilever microvalve can be neglected.Based on the analysis of three main parts (membrane, microvalve and channel) of thermal actuated micropump, the micropump is simulated as whole. Simulation results of flow rate versus driving frequency, pressure head and input power are obtained. It is found from simulation that , when the input power is 1W, the micropump has maximum flow rate at 3.3Hz and the pressure head can raise to 64 kPa when the flow rate is zero. When the input power is low, the flow更多还原