Development of Miniature Precision Progressive Wave Type Piezoelectric Pump

本研究是关于一种新颖的小型压电泵。该泵采用薄振动板，双压电晶片型压电致动器产生行波。该泵及其理论原理在今后的发展中可应用于水冷式移动的计算机、便携式胰岛素注射系统、微型全分析系统（micro-TAS）等。然而，所提出的泵不使用止回阀，并且可以向前和向后两个方向发送流体。在本研究中，首先描述了所提出的泵的原理，然后讨论了通过实验和仿真来检验。研制了两种振动板。一个有四对压电双晶片单元，另一个有两对。通过仿真和实验，研究了两种振动板在双压电晶片单元间存在相位差的正弦驱动下在空气中的运动。本文还对行波在振动板上产生的水流进行了有限元分析。通过实验研究了该泵的特性。结果表明，行波泵原理是有效的。阐明了实验泵在现有条件下的性能和存在的问题，并实现了超薄型原型泵。本文还研究了行波在振动板中的传播效率。尽管进行了各种调查，但通量的量并没有增加那么多。阐明了为获得更大的泵功率，必须增加振动板的刚度。最后阐明了实际应用中的重要技术问题。

This study is about a novel small piezoelectric pump. The pump utilizes a thin vibration plate on which bimorph type piezoelectric actuators generate progressive wave. The pump and its theoretical principle can be developed in the future to be utilized in water-cooled mobile computer, portable insulin injection system, micro-total analysis system (micro-TAS) and so on. Usually, a normal piezoelectric pump needs check valves and sends fluid only in one direction. However the proposed pump doesn't use check valves and can send fluid to both forward and backward directions. In this research, principle of the proposed pump is described at first, and then examination by experiment and simulation is discussed. The authors prepare two types of the vibration plate. One has four pairs of piezoelectric bimorph cells and another has two pairs. Motion of the two types of vibration plates in the air for sinusoidal drive with phase difference among the bimorph cells is investigated by both simulation and experiment. Water flow generated by progressive wave on the vibration plate is also investigated by finite elements analysis. Characteristics of the pump are examined by experiments. As a result, effectiveness of principle of the pump with progressive wave is shown by both experiments and simulations. Ability and problems of the experimental pump in the present condition are clarified.Very thin prototype pump is also realized. Efficiency of propagation of progressive wave in the vibration plate is also investigated. Even though various investigations are carried out, amount of flux doesn't increase so much. It is clarified that stiffness of the vibration plate have to be increase to obtain larger power of the pump. Finally important technical issues for practical use are clarified.