Performance analysis of valveless piezoelectric pump with dome composite structures

Valveless piezoelectric pumps are used in the field of drug delivery. However, the output performances are limited by severe reflux. This article is aimed at reducing the reflux and improving the output performances. We use different pressure loss coefficients in the forward and reverse directions and design dome composite structures within the chamber of the valveless pump. The structures and working principles are described. Then, we use the fluid simulation software CFX to simulate the flow state inside the chamber under different parameters such as the dome length, 2 mm, 4 mm, 6 mm, and 8 mm; the trapezoidal one-sided angle, 1°, 3°, 5°, 7°, and 9°; and the rounded corner, from 0 to 6 mm. Finally, we also make the prototypes and test the output performances. The results show that the output flow rate can reach a maximum of 220.6 ml/min; the measured variance is 80.7 in the three experiment tests for the optimal flow rate at the dome length of 8 mm, angle of 5°, and rounded corner of 6 mm under the driving voltage of 190 V at a frequency of 45 Hz; the highest output pressure is 670.0 Pa under the voltage of 190 V at a frequency of 130 Hz. Moreover, the precision is 5.85% of the highest tested pressure compared to the simulated pressure. The output flow rate has a great improvement, and the effectiveness of the structures is proved.