7 结语
微型流体机械的出现为此领域的工作者提供了一个新的研究方向,同时也提出了新的挑战。随着尺寸的减小,各种力量对比要发生变化,这使得微尺度领域的许多物理现象与宏观世界有很大差别。在微尺度领域,与特征尺寸的高次方成正比的惯性力、电磁力等的相对作用减小,而与尺寸的低次方成正比的粘性力、弹性力、热应力、表面张力、静电力等的作用相对增大。随着尺寸的减小,表面积相对于体积或质量之比相对增大,或者说,研究对象中处在表面上的分子相对于内部分子所占的比重增大;而表面是对象与外界发生联系的界面,因此对象与外界的相互作用相对增强。所有这些对微流体机械的驱动机制的选择及其性能等都有重要影响,有待于进一步研究。
作者简介:尹执中,男,27岁,博士生,1997年开始从事微流动系统的研究,对热驱动微型泵和微型阀的性能进行了较系统的理论和实验研究。通讯地址:100084北京市清华大学工程力学系。
尹执中(清华大学) 胡桅林(清华大学) 过增元(清华大学)
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