Design, Fabrication and Characterization of a Mechanical Micropump

In this paper, a centrifugal micropump was designed, fabricated and characterized. The proposed micropump is able to provide a 1.4L/min flow rate and a 75KPa pressure head at 24000 rpm with an oversize of 46mm wide and 69mm long. The hydrodynamic components were designed based on partial emission pump. Meanwhile, the geometric profiles of both impeller and volute were simplified for manufacturing. A computational fluid dynamics (CFD) analysis was performed to predict the effects of blade inlet angle and vane number on hydraulic performance. Experiments were conducted at 4 different rotational speeds to validate the numerical results. The results showed that the numerical simulation has a high accuracy to predict the micropump flow field with the overall average deviation less than 3%. As expected, the micropump prototype performed obvious partial emission pump features. In terms of the external characteristic, the pressure head at a given rotational speed decreased little with flow rate increasing. While, in the flow field, complex secondary flow was significant in the impeller passage, due to the joint action of the blade tip clearance leakage and axial vortex. Regression analysis and statistical evaluation showed that the flow nondimensional coefficients at different rotational speeds correlated well, indicating that classical similarity rules was still applicable to this micropump.