The role of the supervisor. Although a dissertation is an opportunity for you to work independently, you will usually be allocated a member of academic staff as a supervisor. Supervisors are there to help you shape your ideas and give you advice on how to conduct the research for your dissertation.
The TN device consists of the twisted nematic liquid crystal confined between two glass substrates with homogeneous planar orientation: the orientation of the director n on one substrate is rotated by 90 o with respect to n on another substrate.
Liquid crystals were actually discovered over 100 years ago, but they did not find commercial applications until the invention of the twisted nematic (TN) LCD by Schadt and Helfrich in 1971 (Schadt and Helfrich, 1971). Nematic liquid crystals have a short-range order and have some of the properties of uniaxial crystals.