Pulsation Control Methods And Experimental Research Of Piezoelectric Driven Microfluidic System

Piezoelectric driven microfluidic system has many advantages, such as simple structure, high efficiency and fast response. It is used in more fields due to the continuous development of science and technology. However, piezoelectric driven microfluidic system has pulsation in practical applications, which limits its use in high accuracy and high stability system.In order to improve the accuracy and stability of the system, this paper mainly focus on the research of pulsation reduction from two aspects, driving voltage waveform and fluid filter.First of all, according to the discovery of pulsation generation of the piezoelectric driven microfluidic system, the influence factors of pulsation have been analyzed. On this basis, this paper comparative studied detection methods, including the visual inspection, the electronic balance and the flow sensor. Detection method by the flow sensor has been determined as a kind of objective and feasible method by experiments, because it not only meet the real-time requirements, but also can represent the size of the pulsation visually.Based on the analysis of the influence factors, this paper comparative analyzed the effect of pulsation reduction by different driving voltage waveform, and proposed pulsation reduction methods by the driving voltage waveform correction. Using the theory of rounded diving voltage, researches were used to study the effect of pulsation reduction by different rounded parameters, and the optimal combination of parameter has been obtained on the basis of the velocity stability.With the purpose for satisfactory effect of pulsation reduction, a fluid filter has been designed to reduce pulsation. In the view of the working principle of filter, this paper has studied the influence on pulsation reduction by the factors of the shape of the pipeline, the size of the channel and the radius of the film. At the same time, by means of Comsol, the filter model has been built for simulation analysis, on the basis of the results, the optimal size and structure has been selected.Finally, with the goal of the effective pulsation reduction in a given target velocity, this paper combines the driving voltage waveform correction method with the method of fluid filter, and the effectiveness and reliability of this method is verified by experiments.