Design And Experimental Research Of Piezoelectric Pump With Integrated Piezoelectric Vibrator

On the basis of country natural science fund ―Basic Theory and Experimental Study of Multi Chamber Piezoelectric Pump Used as Blood Pump‖, we start our research. A piezoelectric pump with integrated piezoelectric vibrator is proposed. The integrated piezoelectric vibrator is covered with a layer of medical silicone rubber layer which has excellent flexibility, compressibility and biocompatibility. In the working process of the piezoelectric pump, the silicone rubber layer plays the role of sealing as well as preventing the fluid in the pump chamber contacting with piezoelectric vibrator. Reasonable thickness and compression degree of the silicone rubber layer can amplify the displacement of the integrated piezoelectric vibrator in a large extent. The check valve is affixed to the center of the side surface of the integrated piezoelectric vibrator, so the mechanical energy produced by the vibration of the integrated piezoelectric vibrator can be directly transferred to the check valve, and reduces the step of transmission energy of the check valve as well as the mechanical energy loss during the transmission process. The specific research contents of this paper are as follows:In this paper, vibration model of integrated piezoelectric vibrator is established, and the relative theoretical analyses are presented. According to the Hamilton principle, the motion differential equation and resonance frequency equation of integrated piezoelectric oscillator under different control voltages are derived.The pump chamber height and check valve of the piezoelectric pump are designed and optimized,and dynamic vibration model of the piezoelectric pump is simplified. The influence of the thickness and compression extent of the medical silicone rubber layer on the output performance of the piezoelectric pump is analyzed theoretically, and the output performance of the piezoelectric pump is tested by experiments. The experimental results are as follows: when the thickness and compression distance of the medical silicone rubber layer are 0.3 mm and 0.5 mm respectively, and the pump chamber height of the piezoelectric pump is 1.2 mm, the output performance of piezoelectric pump is optimal.Experimental prototypes of integrated piezoelectric vibrator piezoelectric pump are made, and the relevant experiments are carried out to obtain the optimal driving frequency and phase difference of two integrated piezoelectric vibrators. The experimental results showed: when the two integrated piezoelectric vibrator driven by the same frequency, the output flow rate and pressure of piezoelectric pump drop suddenly; when the first integrated piezoelectric vibrator driving frequency is between 140 Hz- 180 Hz and the second integrated piezoelectric vibrator driving frequency is about 200 Hz, the phase differences between two integrated piezoelectric vibrators are 135°- 225°, the output performance of piezoelectric pump is optimal.Experimental study on the dual integrated piezoelectric vibrator piezoelectric pump pumping blood is carried out, and the process is as follows: Firstly, the experiments of pumping water are carried out to obtain the phase difference and driving frequency of two integrated piezoelectric vibrators when the piezoelectric pump has optimal output performance. Secondly, glycerin water solutions of different viscosity are configured respectively, and experiment for glycerin water solution to simulate blood is carried out in order to obtain the effect of the viscosity of the glycerin water solution on pumping performance of piezoelectric pump. The experimental results show that glycerol water solution viscosity has a great effect on the output performance of the piezoelectric pump, and the output flow of the piezoelectric pump decreases sharply with the increase of glycerol aqueous solution viscosity.