Nematic distortions in adjustable geometries: repartitioning and instabilities

(Received 30 November 1993, revised 25 April 1994, accepted 30 August 1994)

Abstract
Nematic distortion can occur in constraint free systems, where the geometry is adjustable and the nematic is free to repartition itself among various regions. In such cases the nematic distortion gives rise to a term in the free energy which depends on the dimensions of the system. This can produce a mechanical force due to nematic distortions. In turn this leads to a rich phenomenology including a variety of instabilities. Different scenarios are found when the distortions are due to surface alignment and to external fields. These effects are relevant to the understanding of a variety of systems among them nematic gels and nematic systems studied using the force measurement apparatus.