The Influence of the Bi-axial Stretching on the Encapsulated Cholesteric Liquid Crystal on the Flexible Substrate

• Main Authors: Hsuan-Fu Chin, 金軒甫
• Other Authors: 劉育松
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/22t2b7

碩士 === 國立虎尾科技大學 === 電子工程系碩士班 === 100 === In this study, we prepared a encapsulated cholesteric liquid crystal by emulsion method on the flexible and single substrate, and tried to find a best process include adding workability agent or using PEDOT:PSS which can replace ITO as the electrode layer to avoid the properties which ITO is expensive and weak .We also prepared other substrates and expect to develop in 2-D and 3-D display. Use biaxial-stretching system to observe the stress-strain, and use optical measuring system to observe the reflected spectra in high temperature. In our results, film will chap cause damage in high temperature environment (70°C ~76°C) and lead to no driving and the strain of liquid crystal film will increase in lower temperature. Then, we use a new flexible substrate, thermoplastic polyurethane (TPU) for the fabrication of liquid crystal film and measuring the reflectivity spectra at normal incidence in biaxial-stretching. We observed that the reflectivity will increase in whit light incident with strain increase. Use optical microscope to observe the liquid crystal film in uniaxial- stretching, the liquid crystal droplets were changed with stretching direction. The droplets deformed from circle to oval. We measure the reflectivity spectra at normal incidence of cholesteric liquid crystal film which was stretched and stretched before at different angles. When the angle is 0° between incident light and normal line of the cholesteric liquid crystal film, the reflectivity of film which was stretched is higher than stretched before, because the reflect area of encapsulated cholesteric liquid crystal droplets is lager after stretch. When angle between incident light and normal line of the cholesteric liquid crystal film which was stretched increase, the reflectivity of incident light parallel to stretching direction is lower than film which was stretched before and incident light plumb to stretching direction. We also observe that the droplets would deform after coating and lead to reflectivity spectra at normal incidence would be change from broad wavelength range to narrow.