Design Of A New Type Vibrating Mesh Nebulizers Based On Piezoelectric Actuator

Pulmonary drug delivery means that the drug is delivered to the lungs in anon-intrusive way with special devices, and brings out local or systemic treatment effect.The main factors determining the deposition rate in the lungs are the drug formulations andinhalers. In general, drug particle size in1~5μm is regarded with higher deposition rate.The new type vibrating mesh nebulizers are constructed in use of the technology ofsandwich piezoelectric ultrasonic transducer and vibrating mesh plate technology, and cangenerate tiny droplets with narrow size distribution. Therefore, the new type vibratingmesh nebulizers is suitable for submicro-&nano-powder manufacturing instrument–thenano spray dryer. In addition, this novel technology have a great potential application inmanufacturing the new type of medical nebulizers, ink-jet printing and other fields. Themain results in this study is summarized as follows:(1) The mode of vibration of the ultrasound transducer is analyzed and monitored.Based on the theory of piezoelectric coupling, the bolts fastening type piezoelectrictransducer was selected as excitation source of the new type nebulizers, which couldprovide vertical vibration mode.(2) ANSYS is used to analyze the structure of the nebulizers based on thepiezoelectric coupling theory. Modal, harmonic response analysis and transient analysis isused to analyze the vibrating situation of the nebulizers. Based on the finite elementanalysis method, the vibrating mesh nebulizers’ nodal plane position is also analysed, theresults could be used for chose nozzle clamping position.(3) The structure composition, working principle of the spray system is introduced inthis paper. the influence and the reason of the bubble were analyzed when the mesh platewas in vibration. (4) The electronic balance and a video camera were used to catch the data of qualitychange in the working process of nebulizers. It was demonstrated that the flow rate wasaffected by the pore size and the viscosity of liquid, and the bubble was the main reason ofthe changes in the flow rate curve. Scanning electron microscopy (SEM) was chosen to todetermine the size of the water droplets in frozen state, and the particle size proved to bebetween5and20micrometers, suggesting a great potential for submicro-&nano-manufacturing.