Structural Optimization And Simulation Of Valveless Micro-Pump

Micro-fluidic Technology refers to the technology that the complex fluid is controlled, operated and detected under microcosmic sizes. It is a brand new interdiscipline which is developed on the basis of microelectronics, micromachine, bioengineering and nanotechnology. Micro-pump is one of the basic components of Micro-fluidic System.In this paper, theoretical analysis and simulation research is done on valve-less micro-pump based on MEMS, aiming at the demands for quantitative transportation of fluid in the Micro-fluidic System. Diffuser /nozzle is typical valve-less micro-pump which replaces the check valve with passages of different shapes in shrinkage and expansion. It realize the pumping of fluid by making use of the dissymmetry of pressure loss which is caused by dissymmetry of flow passage. In addition to that, it has simple structure and mature technology and therefore, it has drawn universal attention.In this paper, study and analysis is done on the fluid theory and fluid property of diffuser /nozzle. Software Fluent is also adopted to analyze the influence of angle, length, width of diffuser /nozzle on the flux and efficiency and optimize the structure of diffuser /nozzle.Vibration mode of membrane is analyzed and theoretical analysis is done on the process of pump membrane-fluid coupled vibration and approximate analytical solution is acquired. And on the basis of that, the variation of displacement, speed and pump flow of pump membrane with different damping coefficients, driving forces and natural frequencies is acquired by using software PATRAN.The cloud picture for the pressure in the pump chamber and velocity vector chart is obtained by adopting FLUENT to make FEM analysis on the Fluid-Solid Coupling and build three-dimensional flow field and therefore the fluid property of valve-less micro-pump is comprehensively known.The result of study has provided the theoretical basis for structure design of valve-less micro-pump driven by piezoelectricity and it has great value for reasonable design of micro-pump's structure.