Theoretical And Experimental Research On Cymbal-shaped Slotted Valve Piezoelectric Pump

With the development of science and technology and the progress in MEMS manufacturing technology,the more demands for microfluidic transport in the fields such as aerospace,biomedicine and fine chemicals was made,which greatly promoted the development of micro-pumps.The micro-pumps which use piezoelectric material as drive unit,were focused by many researchers both from home and abroad for their merits of rapid response,high energy density,high integration,and electromagnetic noise free operation.They have a brilliant application prospects in the micro-chemical mixing,the fuel cell,biological detection and insulin injection.As the core part of the piezoelectric micro-pump,the reliability of one-way check valve greatly influence on the working life and performance of this micro-pump.When a valve piezoelectric micro-pump works,the reciprocating motion in a high frequency tends to make the valve fatigue damage.Moreover,the traditional cantilever valve easily generates stress concentration which may aggravate fatigue damage and finally induce the valve out of action,which induces the valve piezoelectric micro-pump can not work properly.Therefore,a cymbal-shaped slotted check valve is proposed,which is composed of cymbal-shaped grille and cymbal-shaped slotted diaphragm,to reduce the stress concentration of the valve and thus improve working life and operating reliability of the valve piezoelectric pump.The cymbal-shaped slotted valve piezoelectric micro-pump is designed on the basis of cymbal-shaped slotted valve.In this paper,the research work and the results of the piezoelectric pump and its related components of the cymbal slotted valve are as follows:1.The theoretical derivation of cymbal-shaped slotted diaphragm of cymbal-shaped slotted valve piezoelectric micro-pump is carried out based on the principle of material mechanics and other related principles,and the mathematical expression between the opening and height of cymbal-shaped slotted diaphragm is established.The correlation between each parameter of the diaphragm and opening of diaphragm is clarified;The flow rate expression of cymbal-shaped slotted valve piezoelectric micro-pump is established.And the correlation between the parameters of the oscillator,the parameters of the diaphragm,the parameters of the transmission medium and the pump flow is revealed.2.Based on the comparison of the stress of the cymbal-shaped slotted diaphragm and flat slotted diaphragm with static analysis,the rationality of the design scheme of the cymbal-shaped slotted valve is demonstrated;The wet modal and harmonic response analysis of cymbal-shaped slotted valve piezoelectric micro-pump are conducted overall considering the additional mass influence of pump water into piezoelectric micro-pump.The working frequency of piezoelectric micro-pump and vibration mode of piezoelectric vibrator are confirmed to provide a reference for the construction of the pump flow test platform.3.The fluid-solid coupling model of cymbal-shaped slotted valve piezoelectric micro-pump is established based on the coupling valve body and flow field to deeply analyze the displacement and the stress of cymbal-shaped slotted diaphragm under fluid-solid coupling,and verify the change regulation of pressure and flow field inside piezoelectric micro-pump.Furthermore,the performance of the piezoelectric micro-pump is analyzed,and the feasibility of the design scheme is proved.4.The prototype of cymbal-shaped slotted valve piezoelectric micro-pump is printed out by SLA laser rapid prototyping technology.The output characteristic test platform of cymbal-shaped slotted valve piezoelectric micro-pump is established.The vibrator’s vibration performance and micro-pump’s output characteristic test are conducted to obtain the curve of vibration displacement and pump flow rate under different driving frequencies.The correlation among vibration amplitude,diaphragm stress and pump flow is elaborated on the basis of the fluid-solid coupled results.At the same time,the results can provide a reference for the optimization of the diaphragm.