The Mechanism And Experimental Research Of Microfluidic Atomization Based On Surface Acoustic Wave Technology

Surface acoustic wave(SAW) atomization is a relatively new method in atomization field. The tiny, light configuration, lower power requirement, and higher excitation frequency makes it an ideal candidate in bioengineering and inhalation therapy to generate monodispersed and continuous aerosol.Although it is known that the mechanism responds to atomization, the exact process is obscure due to the difficulty of observing such a small-scale series of complicated hydrodynamic processes related to the acoustic radiation and energy transformation in liquid bulk. Therefore, this study employed fundamental experimental methods to investigate the mechanism for atomization.Firstly, the research analyzes the incentive principle of surface acoustic wave devices and introduces the processing of surface acoustic wave devices and the whole technological process. By analyzing the processing of IDT and meeting the requirement for this experiment, the SAW device was fabricated by UV photolithography technology on a single crystal 128.68 ° y-cut-x lithium niobate(Li NbO3) piezoelectric substrate. The experimental platform for the atomization experiment.The whole atomization process was then recorded by using a high-speed camera and classifying each reaction stage according to the applied power. The experiment reveals three main peaks in the size distribution, and corresponding mechanisms, are employed to provide a detailed explanation for each. Experimental results also show that Eckart streaming and Schlichting streaming dominant different stages in generating different scale droplets, and that the change of the these two kinds of streaming is determined by the aspect ratio(H/L). Methods of predicting the mean diameter of atomized droplets are compared in this work with the result showing the more suitable one to be the method that adopts capillary wave frequency and takes characteristic geometry dimensions into account.Finally, in order to generate a fine mist with high quality, a paper-based atomization platform is constructed to improve the monodispersity of atomized mist. Compared with sessile drop method, the dimeter of droplets produced by paper based method were more centered on 1 μm, which provides lateral evidence that aspect ratio has a crucial role in determining the transformation of acous tic streaming.