Examiner: 263 Professor Torbjörn Lagerwall
Liquid crystals is the name for a number of different forms of condensed matter in between liquids and crystals.These materials are of great interest in basic science and have strongly contributed to the modern understanding of phase transitions and critical phenomen, and to the knowledge of order-disorder phenomena in one, two and three dimensions. From a materials science point of view, their importance increases every year, within optics and electrooptics as well as for polymers and biomaterials. The applications are getting more and more sophisticated, not only for general optics, sensors, modulators and display screens, but also for real-time holograms as elements in optical computers and neural networks. Surface stabilized ferroelectric crystals are presently attracting great interest, among other things for their ability to to simulate the cortex function in the brain (adaptive systems for pattern recognition).
Liquid crystals form a central field within the field of "soft matter", and is a good example of that modern physics can be essentially classical, emphasized by the Nobel Prize awarded to P.G. de Gennes in 1991.
AIM OF SUBJECT
To be able to apply and utilize the possibilities of liquid crystals, one must have good basic knowledge of their physical and, to some extent, chemical properties. The aim of the course is to promote such knowledge, even in the form of certain practical skills, and to discuss present and future technological aspects of the materials. The detailed contents of the course can in practice be largely adapted to the knowledge and interests of the participants.
CONTENT
The pace of basic and industrial research in the field is presently so high that surveys with technical details rapidly become obsolete. The general part of the lectures however present an elementary introduction to liquid crystal physics. Particular emphasis will be put on ferroelectric liquid crystals (FLC), being central for the research of the local group. The first step towards FLC was taken in 1974 in Paris, but they did not become full reality until 1979 at Chalmers. Since the middle 1980's the FLC:s is internationally the strongest growing research field within liquid crystals.
LABORATORY WORK
The laboratory work aims at providing practical knowledge of the different phases of liquid crystals and their optical and electrooptical properties, and also to provide certain skills in preparation of optical cells of interest for general applications.
LITERATURE
Lecture notes.
Recommended reference books:
J. Prost, P.G. de Gennes: The Physics of Liquid Crystals, Oxford 1992.
S. Chandrashekar: Liquid Crystals, Cambridge, 1976.
E.B. Priestley, P. Wojtowicz, P. Sheng: Introduction to Liquid Crystals, Plenum, New York, 1975.
N.A. Clark, S.T. Lagerwall: Ferroelectric Liquid Crystals, Principles, Properties and Applications, Gordon & Breach 1992; Chapters 1 and 6.
Physics Today, May 1982.
EXAMINATION
Written and/or oral exam.