Rigid and deformable bodies in nematic liquid crystals

A nematic liquid crystal, a phase of matter composed of rodlike molecules, exhibits a tendency towards uniform molecular alignment. Bodies inserted into such a fluid can disturb this orientational order, resulting in elastic stresses bound in the bulk fluid and exerted on the body surfaces, even at equilibrium. One avenue of energy relaxation is by a change in the immersed particle positions and orientations, leading to elastic forces and torques that bodies exert on each other through the fluid. Soft particles offer an additional means of relaxation, deformation, which in turn can modify particle interactions through the LC medium. We review classical work on rigid particles and their interactions in nematic liquid crystals and more recent work on the shapes and interactions of deformable bodies in LCs. In addition to experimental findings, a number of common mathematical modeling techniques, both in terms of a director field n and a second-order tensor field Q , are introduced throughout, including derivations of body forces and torques and, of particular use in the study of deformable media in LCs, surface tractions and moments.