Performance Of Series Valveless Piezoelectric Micropump And Experimental Study

Valve-less piezoelectric micro-pump is a component which uses piezoelectric vibrator to exert mechanical voltage,and changes the volume of pump chamber to generate pressure difference between inside and outside of pump chamber,so as to achieve continuous flow of fluid components.The advantages of the pump are simplemechanism,easy processing,stable performance,which make it becomeone of the most important fluid-driven devices in analytical systems of the mechanical and electronic,and is widely used in fine chemical aerospace.Due to the weak pumping performance of the single-chamber valve-less piezoelectric micro-pump,a series valve-less piezoelectric micro-pump is proposed in this paper,and the theoretical analysis and experimental research are carried out.The oretical analysis:through the theory of the working principle of contraction/dilatation tube,the principle of piezoelectric effect and the efficiency of the valve free microchannel,a suitable piezoelectric vibrator is selected and the resistance characteristics of the contraction/dilatation tube are analyzed,and the basic schematic diagram of the valve free micro pump is drawn,and the "drawing mode" and the "pump mode" of the micro pump are drawn.Schematic diagram,and then leads to the working mode of the double chamber series valveless piezoelectric micropump,and draws a schematic diagram of the working mode of the double valve series valve less micropump.Then the FLUENT software is used to simulate the microfluidic flow of the micro pump,and the pressure and velocity images of the micro pump "draw mode" and "pump mode"are obtained,and the maximum velocity and maximum pressure of the microfluidic channel are obtained from the cloud map.Experimental aspects:the main pump body was made by the wet etching process of glass,and the PDMS pump membrane was made by the method of Spin coater in injection molding,and the mold fixture was manufactured by the machining processing.Each component of the micro-pump was encapsulated to produce a series micro-pump in the form of PDMS-glass-PDMS sandwich.Then with the data consulted,the appropriate power amplifier chip was selected,the power amplifier was made and the magnification of the power amplifier was determined.The flow measurement and control system was set up based on the micro pump.And the flow rate of the series micro-pump under different parameters was measured and the data are collected.Then the data of the experiment were processed by MATLAB in order to get the curves of the flow with voltage,frequency,phase and waveform.The initial exploration of the micro pump vibration experiment was carried out,and the vibration measurement and control system centered on the micro pump was set up,and the vibration measurement and control system was analyzed.The results of the experimental data show that the flow of double-chamber series valve-less piezoelectric micro-pumps changes obviously with frequency and the graph shows a parabola Form whether in the excitation of sine wave signal or the excitation of square wave or ramp signal.The maximum flow rate is 79.52ul/min which will be reached in the case of the voltage of 130 Vpp,the frequency of 150Hz and the oblique wave of 20%-20%symmetry.The maximum flow rate is 79.52ul/min.When the voltage of the micro-pump is 130Vpp,the frequency is 150Hz,and the ramp is 20%-20%symmetry,the amplitude of the piezoelectric vibrator increases as the voltage increases,and The overall amplitude of the rear pump is larger than that of the front pump.The maximum amplitude of the front pump is 0.86um.When the sine wave is driven at 130Vpp and the frequency is 50Hz,the maximum amplitude of the rear pump is 2.7um.