Parametric study of droplet wettability under electric field

• Main Author: Wang, Chenweiyi
• Other Authors: Tran Anh Tuan
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/70934
• Institution: Nanyang Technological University

Electrowetting is a phenomenon that used to explain how the wettability of liquid on solid surface can be controlled via applying voltage. Such liquid is extracted with very minor amount to test on the various surfaces. In this project, we intend to investigate whether the substrates are suitable for the droplets to perform under low voltages. Firstly, we would start off by studying various materials for substrates and analyse them, to choose suitable materials to manufacture them. These materials are namely silicon nitride, SU-8-2000 and Teflon AF 1600. The result compared between applied voltage and threshold voltage, with a range of substrate thickness. We also propose suitable materials for substrate and its coating. Secondly, after the suitable materials were found, we then proceed to learn how to manufacture these samples, as well as design the substrates and coating. These methods such as chemical vapour deposition. They are supposed to be made with desirable uniform thickness as to handle problems such as material failure and dielectric breakdowns. Thirdly, to investigate whether the substrate (with coating) will work or not, we would test them via applying various concentration of newtonian fluid, Glycerol on them. Data are collected from transient state to steady state, after the experiments were conducted repeatedly. These data were then being analysed and conclude whether such substrate is suitable to ensure the droplets are able to perform under low voltages. Lastly, the result of Newtonian fluid are also used to compare with non-newtonian fluid, namely Chitosan solution, cells and media. The chitosan solutions were made with similar level of its intrinsic viscosity and compared them with Glycerol.