Improvement And Fabrication Of Double Nozzle-Diffuser Valveless Micropump

Nozzle/diffuser valveless micropump can be integrated in micro fluidic chip as a fluid drive element, so it keeps a focus in micro fluid field, and get prominently developed. Nowadays, nozzle/diffuser micropump still have a low flow, cannot meet some requirement. Therefore, double nozzle/diffusers micropump is fabricated which has a higher flow without volume increase.The theory of nozzle/diffuser valveless micropump is analyzed, the equations are induced, and flow characteristic of nozzle/diffuser element is researched. Structure of the valveless micropump is researched, double nozzle/diffuser structure is presented after study of former research. Work status of valveless micropump is simulated by FEA software ANSYS, transient multiple coupling which combined with piezoelectric coupling and FSI coupling is executed. The results indicate that under the same condition, transient flow of double nozzle/diffuser micropump is higher than single nozzle/diffuser micropump, and with voltage increase, the ratio of flow between the two types of micropump increases, it can be up to 79% under a voltage of 170V.By MEMS technics including clearing, oxidation, photolithography, anisotropy etch, bonding, etc., single and double nozzle/diffuser micropumps are fabricated, ensure that two types of micropump have the same condition including PZT with membranes with same performance and same encapsulating materials, while only except numbers of nozzle/diffuser.Test single and double nozzle/diffuser micropumps and compare them. Under drive voltage of 170V and frequency of 560Hz, flow of double nozzle/diffuser micropumps is 1.5mL/min, while the single's is 902μl/min. under the same 170V and 500Hz, flow of double nozzle/diffuser micropumps is 56% higher than that of single. The results show double nozzle/diffuser structure of micropumps increases the flow, it accords to the simulation results.