Experimental and theoretical investigations into the switching of liquid crystal devices

Hind, J., 2007. Experimental and theoretical investigations into the switching of liquid crystal devices. PhD, Nottingham Trent University.

Preview

Text 194144_Hind.pdf Download (2MB) | Preview

Abstract

This work addresses the dynamic switching of liquid crystal cells. While static measurements of the permittivity liquid crystal cells are well established, here a novel transient permittivity technique is developed and applied to several liquid crystalline substances in a variety of geometries. This technique utilises A.C. waveforms to measure the permittivity of a cell during the dynamic processes of switching and relaxing, allowing a detailed picture of the switching process to be constructed on small time scales. The results for several materials are presented and compared to theoretical predictions stemming from standard liquid crystal continuum theory. The technique is expanded to utilise frequency modulation when applied to dual frequency materials and is adapted to D.C. fields. Novel experimental results concerning surface stabilised ferroelectric liquid crystals have recently shown an unexpected second minimum in the tau-V response curve. The origin of this phenomenon is explored via a numerical simulation program and a qualitative explanation found regarding the torque generated by the surface alignment that is consistent with established theory.

Item Type:	Thesis
Creators:	Hind, J.
Date:	2007
Rights:	This work is the intellectual property of the author, and may also be owned by the research sponsor(s) and/or Nottingham Trent University. You may copy up to 5% of this work for private study, or personal, non-commercial research. Any re-use of the information contained within this document should be fully referenced, quoting the author, title, university, degree level and pagination. Queries or requests for any other use, of if a more substantial copy is required, should be directed in the first instance to the author.
Divisions:	Schools > School of Science and Technology
Record created by:	EPrints Services
Date Added:	09 Oct 2015 09:36
Last Modified:	09 Oct 2015 09:36
URI:	https://irep.ntu.ac.uk/id/eprint/362

Actions (login required)

Edit View

Views

Downloads