Development of Miniature Precision Progressive Wave Type Piezoelectric Pump

本研究是关于一种新型小型压电泵的研究。该泵采用薄振动板，双压电致动器在其上产生行波。该泵及其原理可在未来发展应用于水冷移动计算机、便携式胰岛素注射系统、微量全分析系统等。通常，普通压电泵需要止回阀，并且只向一个方向输送流体。然而，该泵不使用止回阀，可以向前和向后输送流体。在本研究中，首先描述了所提出的泵的工作原理，然后对其进行了实验和仿真验证。作者研制了两种类型的振动板。其中一个有四对压电双晶片电池，另一个有两对。采用数值模拟和实验相结合的方法，研究了双压片单元间相位差正弦驱动时两种振动板在空气中的运动。对行波作用下振动平板上的水流进行了有限元分析。通过实验对该泵的特性进行了检验。通过实验和仿真，验证了行波泵原理的有效性。阐明了试验泵在现有条件下的性能和存在的问题，并实现了超薄样机泵。文中还研究了行波在振动板中的传播效率。即使进行了各种调查，通量的量也没有增加那么多。阐明了要获得更大的泵功率，必须增加振动板的刚度。最后阐明了具有实际应用价值的重要技术问题。

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.