The proposed work centers on the development of reverse mode polymer dispersed liquid crystal materials. These materials, which will be fabricated either as films or as encapsulated droplets, are radically different from other liquid crystal devices, including normal mode polymer dispersed systems. The important distinction of reverse mode materials is that they represent an optically transmissive state in the absence of applied fields and are converted to an opaque light scattering state when a field is applied. Their field-off/field-on behavior is exactly opposite to that normally associated with optical properties of liquid crystal materials, thus giving rise to the reverse mode designation. There are numerous major and unique commercial opportunities for these reverse mode polymer dispersed liquid crystal materials. They include architectural use as "smart windows" for energy savings in commercial and residential buildings; privacy windows in automobiles; and as a new approach to heads-up display technology. The unique feature of reverse mode materials with respect to these applications, as contrasted with other liquid crystal light shutters, centers on the fail-safe aspect in that they are transparent in the absence of an applied field. Thus, unscheduled power outages will not create hazardous situations. The economic factors in commercialization would be most favorable in that these reverse mode materials are relatively inexpensive to produce. The focus of the phase I experimental effort is to improve the overall optical properties of reverse mode polymer dispersed liquid crystal materials. In particular, systematic studies will be conducted to optimize the percent transmission of these materials in the transparent field-off state through modification of the shapes and sizes of the liquid crystal microdroplets.
