Electrowetting display with a curable double emulsion array

• Main Authors: Meng-Tsung Chang, 章孟琮
• Other Authors: 范士岡
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/50218525872811071791

碩士 === 國立臺灣大學 === 機械工程學研究所 === 105 === We combined formation of double emulsions in microchannel and deformation of the inner droplet with electrowetting-on-dielectric (EWOD) to demonstrate an electrowetting display (EWD) avoiding sophisticated fabrication with the photolithography process and ink injection that current EWD faces. We used microfluidic emulsion to form the pixels and to pack the double emulsions in a single microfluidic chip with microchannels. The strategy was producing a double emulsion array with microchannels and controlling the shapes of the inner droplets by EWOD to achieve the display functionalities. Three curable liquids were adopted and investigated as the continuous phase of the double emulsion: UV curable MD 700, PEGDA, and thermally curable PDMS. The dispersed phases contained inner and outer droplets of immiscible fluids. The emulsions were stabilized by surfactants or the viscosity of the continuous phase composed of long-chain molecules. We first studied the creation of single emulsion arrays with four different combinations: water in MD 700, glycerin in PDMS, Novec 7500 in PDMS, and silicone oil in PEGDA. We further examined and succeeded to form double emulsion arrays that were uniformly and regularly arranged using PEGDA , silicone oil, and Novec 7500 as the continuous phase, outer droplet, and inner droplet, respectively. The emulsion array composed of outer droplets with diameter of 200 μm and height of 150 μm was actuated with EWOD by applying a 160 Vpp and 100 kHz AC signal. The inner droplets spread as voltage applied and recovered as voltage removed which demonstrated the function of a double emulsion electrowetting display.