The effect of nozzle layout on droplet ejection of a piezo-electrically actuated micro-atomizer

作     者：Yanying Feng Zhaoying Zhou Junhua Zhu Guibin Du 

作者机构：Department of Precision Instruments and Mechanology.Tsinghua University Beijing 100084. China State Key Laboratory of Transducer TechnologyChinese Academy of Sciences Beijing 100080. China 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2007年第23卷第2期

页      面：163-172页

核心收录：

学科分类：08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 080402[工学-测试计量技术及仪器] 081101[工学-控制理论与控制工程] 0811[工学-控制科学与工程] 

基　　金：the National Natural Science Foundation of China(50405001) 

主　　题：Nozzle layout . Fluid solid coupling . Modal analysis . Micro atomizer . MEMS 

摘      要：We study here effects of nozzle layout on the droplet ejection of a micro atomizer, which was fabricated with the arrayed nozzles by the MEMS technology and actuated by a piezoelectric disc. A theoretical model was first built for this piezoelectric-liquid-structure coupling system to characterize the acoustic wave propagation in the liquid chamber, which determined the droplet formation out of nozzles. The modal analysis was carried out numerically to predict resonant frequencies and simulate the corresponding pressure wave field. By comparing the amplitude contours of pressure wave on the liquid-solid interface at nozzle inlets with the designed nozzle layout, behaviors of the device under different vibration modes can be predicted. Experimentally, an impedance analyzer was used to measure the resonant frequencies of the system. Three types of atomizers with different nozzle layouts were fabricated for measuring the effect of nozzle distribution on the ejection performance. The visualization experiment of droplet generation was carried out and volume flow rates of these devices were measured. The good agreement between the experiment and the prediction proved that only the increase of nozzles may not enhance the droplet generation and a design of nozzle distribution from a view-point of frequency is necessary for a resonant related atomizer.