Originally posted by: Moonbeam
Ordinary fluids are isotropic in nature: they appear optically, magnetically, electrically, etc. to be the same from any perspective. Although the molecules which comprise the fluid are generally anisometric in shape, this anisometry generally plays little role in anisotropic macroscopic behavior (aside from viscosity). Nevertheless, there exists a large class of highly anisometric molecules which gives rise to unusual, fascinating, and potentially technologically relevant behavior. There are many interesting candidates for study, including polymers, micelles, microemulsions, and materials of biological significance, such as DNA and membranes. Although at times we have investigated all of these materials, our primary effort centers on liquid crystals.
Liquid crystals are composed of moderate size organic molecules which tend to be elongated and shaped like a cigar, although we have studied, and the literature is full of variety of other, highly exotic shapes as well. Because of their elongated shape, under appropriate conditions the molecules can exhibit orientational order, such that all the axes line up in a particular direction. In consequence, the bulk order has profound influences on the way light and electricity behave in the material. For example, if the direction of the orientation varies in space, the orientation of the light (i.e., the polarization) can follow this variation. A well-known application of this phenomenon is the ubiquitous liquid crystal display, now comprising a $15b annual industry world-wide. Under other conditions the molecules may form a stack of layers along one direction, but remain liquid like (in terms of the absence of translational order) within the layers. As the system changes from one of these phases to another, a variety of physical parameters such as susceptibility and heat capacity, will exhibit "pretransitional behavior." Based solely on symmetry, this behavior may be related to other physical systems, such as superconductivity, magnetism, or superfluidity; this is the so-called "universality" of these phase transitions.
Using a battery of optical techniques, in addition to dielectric and certain surface probes, our research centers on the role of symmetry on liquid crystalline phases and phase transitions, how these systems behave in the presence of intense magnetic and electric fields, and the effects of confining these materials in spaces not much larger than the molecules themselves. By observing this behavior, we learn not only about the particular material under consideration, but about the global properties of anisotropic fluids and their relationships to other physical systems. Finally, we should point out that although our research is primarily fundamental in nature, determining critical exponents, surface potentials, induced polarizations, etc., a small but important component of our effort involves technology. For example, we have developed a new liquid crystal display architecture which is being developed for commercialization by American industry. This is a symbiotic approach to research, and has been an intellectual stimulation to our effort.
From here.