Measuring the twist elastic constant of nematic liquid crystal by in plane electrode structure

• Main Authors: Cheng -Ta Yang, 楊政達
• Other Authors: Ru-Pin Chao Pan
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/56988355463664060550

碩士 === 國立交通大學 === 電子物理系所 === 93 === A method of measuring the twist elastic constant (K22) of a nematic liquid crystal (NLC) has been demonstrated. This constant is an important parameter of NLC for both fundamental research and applications. It is also often required to experimentally deduce other parameters of NLC, such as azimuthal anchoring strength. A simple method without applying magnetic field is on demanding. We measured the K22 with a homogeneous cell with laser beam (632.8 nm). An in-plane-switching configuration was used to apply the electric field. The constant can then be obtained by measuring the threshold voltage. The temperature dependence of K22 of 5CB and E7 are measured. The results are compared with other literatures.