Structure Design And Experimental Study Of The Fishtailing Type Piezoelectric Pump

As a combination of micro pump technology and intelligent material technology equipment,The piezoelectric pumps have advantages in some specific application scenarios.Dynamic Piezoelectric pumps are more suitable for the application of large flow scenarios under low back pressure.With rational working condition design,the pump can work at the best efficiency point,where can save energy.As a typical type of dynamic pump,the piezoelectric pump is simple and reliable in structure,and its comprehensive output performance is better than the similar pumps.However,there are few researches on this type of pump at present,and the basic theory needs to be improved.Firstly,the displacement and mechanical output characteristics of the core power component of the piezoelectric pump,the cantilever twin-chip piezoelectric actuator(hereinafter referred to as the actuator)and the resonant frequency of the actuator with any width are deduced,and the dimensional parameters and materials of the actuator are determined.Secondly,combined with the description of the fish undulating motion model in bio-fluid mechanics,the output flow rate,output pressure,output power and working efficiency formulas of piezoelectric pump were deduced,and the influence of actuator structure and movement mode on the above performance parameters was determined.The analysis results show that the output capacity of the pump is mainly affected by the amplitude and width of the oscillator tail.When the second order mode node of the vibrator is closer to the fixed end of the cantilever actuator,the motion curve of the actuator is closer to the body-caudal fin(BCF)motion mode.Then,in order to improve the second-order mode node position distribution of the actuator,the numerical simulation model of the actuator structure optimization was developed by using COMSOL Multiphysics,and the trapezoidal actuator was designed to meet the requirements of the motion form.In addition,in order to ensure that the tail width of the actuator increases without affecting its motion form,a compound trapezoidal actuator with light material tail is designed on the basis of the trapezoidal actuator.The simulation analysis and experimental study of the piezoelectric vibrator before and after optimization are carried out.The results show that the piezoelectric actuator designed in this paper has better comprehensive performance.Finally,the experimental prototype of the fishtailing type piezoelectric pump was manufactured,and the experimental platform was built.The rectangular and compound trapezoidal actuators were used as the driving parts of the pump to carry out the experimental research.The output capacity of the pump using compound trapezoidal actuator is improved compared with that of pump using the rectangular actuator.Under the voltage of 100 V,the output flow of the compound pump using trapezoidal actuator can reach 16.2 ml /min at the driving frequency of 327 Hz.Under the same conditions,the maximum output flow is 1.84 times larger than that of pump using the rectangular actuator.At this time,the maximum output pressure of the piezoelectric pump was measured to be 11 mm water column.The experimental results show that the output flow rate decreases with the increase of the aspect ratio of the tail profile.With the increase of tail width,the output flow rate increases.The output flow rate decreases with the increase of the distance between the actuator and the outlet.This study shows that the trapezoidal piezoelectric actuator with light tail is used as the power component of the fishtailing type piezoelectric pump,which has advantages in performance under the same conditions and is a supplement to the existing research.It is hoped that the theory of the fishtailing type piezoelectric pump and the actuator shape optimization design theory proposed in this paper will provide some inspiration for the future research and development of this type of piezoelectric pump.