請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/69913
標題: | 液滴在振動板上之振盪模態與移動機制探討 A study of the drop vibrating mode and its moving mechanism for drop on a vibrating plate |
作者: | Chung-Hao Wang 王重皓 |
指導教授: | 王安邦(An-Bang Wang) |
關鍵字: | 液滴,振動平板,液滴移動控制, sessile drop,drop mode,drop motion, |
出版年 : | 2018 |
學位: | 碩士 |
摘要: | 本研究探討原靜置於平板上的液滴受到平板振動所引致的作用力後,能激發出其特定的液滴振盪模態,甚或於平板上產生移動之現象。主要可以分為三大部分,一為垂直振動平板上之液滴模態,第二部分為水平振動平板上之液滴運動,最後一部分為製作二維度無需預埋路徑的液滴操控平台。
本研究在第一部分發現液滴模態在垂直振動平板上會受位置影響,於相同的液滴大小與振動頻率下,有多個不同模態同時間產生,其原因是平板之彈性,造成振動平板徑向上的垂直振幅量不同,導致不同位置上加速度值之差異,進而引致產生不同的液滴振動模態。 而在第二部分水平振動平板之液滴運動部分,首先藉由實驗定量分析平板振動與液滴接觸角變化之關係,發現液滴接觸角的變化來自其質心受平板作用力後的左右擺盪運動所致,此研究中藉由追蹤液滴最高點之位移以替代不易從影像解析的質心運動,證實平板的水平加速度運動先帶動液滴最高點之擺盪,進而使液滴與平板之接觸角逐漸增加而後產生移動現象。對於液滴的移動方向,本研究發現可用基板之振動頻率與振動的振幅量來控制,不同之振動頻率可以激發出不同振動模態,再由振動模態進而影響液滴之移動方向,振幅則是超過一閾值後會發生轉變方向之行為,然後並以此兩參數繪製一相圖,說明頻率與振幅對應移動方向之關係,以達到液滴控制最佳化之目的。 最後,以第二部分作為基礎,本研究自行開發一個二維度之液滴操控運動平台,可操控液滴體積範圍從5~100μl,控制液滴之移動除了在兩個振動的軸向運動外,還能有斜走的行為產生。此外,本平台還能提供選擇性的控制液滴移動,即讓部分液滴運動與部分液滴不運動,此無需預埋運動路徑式的控制平台設計,在微流系統的應用上,應有著極大潛力。 When the drop is subjected the force caused by vibration, it can stimulate the oscillating mode or even drop motion. The topic can be divided into three parts. First, we discuss the drop oscillating mode on the vertical vibrating plate. Second, we discuss how the drop can move on the horizontal vibrating plate. Final, we manufacture the two-dimension platform to manipulate the drop motion. We find that droplet modes are affected by position on the plate. Even in the same operating conditions, like droplet size and vibrating frequency, but there are many different modes shown in different locations. The reason of the different modes shown at same time is the elasticity of plate. It causes the different amplitude of plate in the radial direction, so the drop modes are different in the plate. As for the drop motion part, first of all, the quantitative analysis of the relationship between the plate vibration and the contact angle of the droplet shows that the change of the contact angle is caused by the movement of the droplet centroid driven by the plate force. In this study, we track the displacement of the highest point of the droplet to replace the centroid motion that is difficult to be resolved from the image. The acceleration of the plate drives the highest point of the droplet to swing, so that the contact angle gradually increases and drop move after it overcome the threshold. In addition, for the direction of droplet movement, the present study found that the amplitude and the frequency of the plate can be used to control the direction of droplet motion. And then we draw a phase diagram with these two parameters, indicating the relationship between the frequency and amplitude corresponding to the direction of movement in order to achieve optimal droplet control. Finally, on the basis of the second part, we develop a moving platform that expands the two-dimensional droplet manipulation from the original one-dimensional droplet control by ourselves. This motion platform manipulates the droplet volume range from 5~100μl. The drop motion is not only on the axial direction but also the behavior of oblique walking. In addition, this platform has the selective control of droplet motion, allowing some droplet movement, which has great potential in microfluidic systems. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/69913 |
DOI: | 10.6342/NTU201800548 |
全文授權: | 有償授權 |
顯示於系所單位: | 應用力學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-107-1.pdf 目前未授權公開取用 | 5.89 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。