Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1861
標題: 徑向擠壓式壓電驅動液滴產生系統設計
Design of Droplet Generation System Driven by Radial Squeezing Type PZT
作者: 吳培民
Wu, Pei-Min
關鍵字: Generation system;液滴產生系統;Squeezing;擠壓式
出版社: 機械工程學系所
引用: [1] D.B. Bogy and F.E. Talke, “Experimental and Theoretical Study of Wave Propagation phenomena in Drop-on-Demand lnk Jet Devices” ,1984, ,IBM J.Res Develop,Vol.28 [2] N. Bugdayci and D.B. Bogy, “Axisymmetric Motion of Radially Polarized Piezoelectric Cylinders Used in lnk Jet Printing”,1983,IBM J.Res Develop,Vol.27, pp. 171-180 [3] V. Callil1, “Introduction to Digital Printing Technology”, Graphic Artists, Pre-Press Personnel,Bobbin Magazine [4] P.H. Chen and H.Y. Peng, “Pressure response and droplet ejection of a piezoelectric inkjet printhead”, 1999, International Journal of Mechanical Sciences, Vol. 41, pp 235-248 [5] B.J. de Gans and U.S. Schubert, “Inkjet Printing of Polymer Micro-Arrays and Libraries: Instrumentation, Requirements, and Perspectives”, Macromol. Rapid Commun, 2003,Vol.24,pp.659-666 [6] B. de Heij and C. Steinert and H. Sandmaier, “A tunable and highly parallel picoliter-dispenser based on direct liquid displacement”, 2002, IEEE, pp 706-709 [7] K. Hakiai, Y. Ishida, “Electrostatic Droplet Ejection Using Planar Needle Inkjet Head”,Applied Physics , 2005,Vol. 44, pp. 5781-5785 [8] K. Hakiai, Y. Ishida, “Electrostatic Inkjet Patterning Using Si Needle Prepared by Anodization”,Applied Physics , 2005,Vol. 44, pp. 5786-5790 [9] R. Muller and W. Berger, “all-diamond-inkjet for dispension of aggressive liquids”, 2005, IEEE, pp 229-230 [10] G. Perçin and B. T. Khuri-Yakub, “Piezoelectric droplet ejector for ink-jet printing of fluids and solid particles”, 2003, Review of Scientific Instruments, Vol. 74 [11] C.P. Steinert and I. Goutier, “An improved 24 channel picoliter dispenser based on direct liquid displacement”,2003, IEEE-Transducers, pp. 376-379 [12] H.C. Wu and H.J. Lin, “A Numerical study of the effect of operating parameters on drop formation in a squeeze mode inkjet device”, Modelling and Simulation in Materials Science and Engineering, 2005, Vol. 13, pp. 17-34 [13] A.S. Yang and J.C. Yang, “Droplet Ejection Study of a Picojet Printhead”,Journal of Micromechanics and Microengineering, 2006,Vol. 16, pp. 180-188 [14] B.Zhmud, “Innovative Development of the Inkjet Technology”, Institute for Surface Chemistry [15] 蔡一坤,“穿透現象和液滴形狀的關係”,北京大學物理系論文, 1996。 [16] 楊實文,“壓電噴墨頭-微陣列致動器之設計與製作”,大葉大學機械工程研究所碩士論文, 2003。 [17] 蔡煒銘,“擠壓式壓電噴頭噴墨行為之數值研究”,大葉大學機械工程研究所碩士論文, 2005。 [18] 林俊偉,“液滴形成的流體特性模擬”,中興大學機械工程研究所碩士論文, 2006。
摘要: 
本文利用傳統加工方式,設計製作液滴產生系統。首先,對壓電管進行變形量之量測,並利用軟體分析、驗証壓電管在內、外表面的徑向變形量;再利用高速攝影機拍攝液滴之動態生成行為及運動特性,以及進行驗證液滴體積估算。其中,操作條件如下:(a)輸入Vac=95~145V時, (b)操作頻率在f=1100~800Hz,實驗中噴頭直徑為105μm。外表面塗佈疏水性材料,有助於液滴形成。重要結論如下:
1、驅動交流電壓越高時,管壓電的徑向變形量愈大。另外,當驅動電壓固定時,壓電管之徑向振動速度與驅動頻率成正比,但對其徑向變形量並沒有明顯變化。
2、增加驅動電壓與週期對斷裂後主液滴和衛星滴之相對運動具有影響。基本上,可觀察到四種變化過程:(a)單一主液滴狀態、(b)主液滴與衛星滴同步狀態、(c)主液滴追撞前行衛星滴狀態、(d)主液滴和前後衛星滴追撞狀態。
3、從主液滴運動的速度-時間變化曲線上觀察到三個共同特徵點分別為:(a)液滴初速度點、(b)速度折返點、(c)液滴斷裂點。
4、驅動週期、電壓均和噴出流量成正比亦驅動電壓越大,液滴斷裂長度愈長。
5、在主液滴運動過程(狀態一、二)中具有振盪特性,在狀態一與狀態二時,液滴的振動週期約在0.38ms~0.4ms,此一週期約與單一自由液滴之振動週期相近。

This study presents the design process of a droplet generation system with the traditional manufacturing process. Also, the performance of this self-design system is evaluated and the droplet flow patterns are summarized. In this study, the pulsating amplitude of the radial squeezing type PZT is measured first by laser Doppler’s vibrometer. Then the numerical analysis is performed using finite element method to validate the pulsating amplitude at the outer surface of the PZT. The driving voltages and frequencies range within 95V~145 V and 800 Hz~1100 Hz, respectively. Furthermore, the outer surface of the nozzle is coated with hydrophobic material to avoid ahersion onto the nozzle surface. The important results are summarized as follows:
1、The higher the driving voltage‚ the large the pulsating amplitude at the inner and the outer surface of the PZT. In addition‚ the pulsating velocity of the PZT in the radial direction was proportional to the driving voltage‚ but was independence of the driving frequency.
2、There are four patterns of the moving droplet: (a) Primary droplet only pattern, (b)The primary and satellite droplets move synchronously, (c)The primary droplet merges with the preceding satellite droplet, (d) The primary droplet merges with both the preceding and the following satellite droplets.
3、There are three characteristics in the velocity-time curve of the moving droplets. Namely‚ (a) magnitude of the initial velocity‚ (b) The instant of maximal velocity‚ (c) The instant of droplet pinch-off. Also, for the first three patterns‚ the oscillation characterization is found both in the velocity and the shape of the merged droplets.
4、In the first to three patterns‚ the merged droplets experienced oscillations both in the shape and in the velocity. For the first two patterns, the measured oscillating frequency is 0.38ms~0.4ms, which is very close to that of a free single droplet. However‚ for the third pattern‚ the measured oscillating period slightly deviates from that of a free single droplet because of strong interaction between the primary and the satellite droplets.
URI: http://hdl.handle.net/11455/1861
其他識別: U0005-1812200715352700
Appears in Collections:機械工程學系所

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