SBIR Phase II: Thresholdless Ferroelectric Liquid Crystals

SBIR 第二阶段：无阈值铁电液晶

• 批准号: 0078722
• 负责人: William Thurmes
• 金额: $ 39.92万
• 依托单位: Displaytech Incorporated
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0078722&HistoricalAwards=false
• 关键词: SBIR; Phase; II; Thresholdless; Ferroelectric

This Small Business Innovation Research Phase II project's goal is a commercialquality liquid crystal exhibiting V-shaped switching with no hysteresis. This LC will beused in gray-scale displays and telecommunications optical switches.Ferroelectric liquid crystals (FLCs), due to their fast switching speed and wideviewing angle, have inherent advantages over the more commonly used nematic liquidcrystals. However, when used in displays, they have a disadvantage - they generally canbe driven to only two states, on and off. Since displays require intermediate gray states,FLCs currently attain gray scale by rapidly switching on and off. This project uses a newtype of FLC which, in addition to its speed and viewing angle advantage, also showsanalog switching. This type of material, previously known as a "thresholdlessantiferroelectric", is now known to be an FLC with a linear optical response to appliedfield (also known as "V-shaped switching").This project's objective is to make new liquid crystal compounds and mixtures thatexhibit V-shaped switching. Towards that end, a variety of cores, chiral tails, and achiraltails, all of which are either known or suspected to promote a de Vries-type smectic A,have been proposed. About 50 - 100 liquid crystals will be synthesized by combiningthese various components. These new LCs will be combined with LCs made in the PhaseI or earlier, giving mixtures that ideally will have not only a de Vries smectic A phase,but also a wide room-temperature smectic C phase, good low-voltage analog electroopticresponse, good alignability, and fast hysteresis-free switching. An optimal alignmentlayer configuration will be determined. The newly formulated mixtures will be placed incells containing this alignment layer to give V-shaped switching displays.This project could be instrumental in advancing our knowledge of the root causes ofV-shaped switching in FLC and, by extension, add insight into the responses of self-assembling molecules to applied forces. In addition, since the interaction of the alignmentlayer with the liquid crystal is crucial for V-shaped switching, much more so than fortypical FLCs, this project will provide a better understanding of the alignment layer-LCinteractions.

这个小型企业创新研究第二阶段项目的目标是一个商业品质的液晶显示V形开关没有滞后。铁电液晶（FLC）由于其开关速度快、视角宽，与常用的液晶相比具有固有的优势。然而，当用于显示器时，它们有一个缺点-它们通常只能被驱动到两种状态，开和关。由于显示器需要中间灰度状态，FLC目前通过快速打开和关闭来获得灰度。该项目采用了一种新型的FLC，除了其速度和视角优势外，还显示了无源切换。这类材料以前被称为“无阈值反铁电体”，现在被认为是一种对外加电场具有线性光学响应的FLC（也称为“V形开关”）。为此，已经提出了各种核、手性尾和非手性尾，所有这些都是已知的或被怀疑促进德弗里斯型近晶A。通过组合这些不同的组分将合成约50 - 100种液晶。这些新的液晶将与第一阶段或更早阶段制备的液晶相结合，得到理想的混合物，不仅具有德弗里斯近晶A相，而且具有宽的室温近晶C相，良好的低压模拟电光响应，良好的可重复性和快速的无闪烁开关。将确定一个最佳的缓冲层配置。新配制的混合物将被放置在含有这种取向层的电池中，以产生V形开关显示器。这个项目可能有助于推进我们对FLC中V形开关的根本原因的认识，并通过扩展，增加对自组装分子对施加力的响应的洞察。此外，由于取向层与液晶的相互作用对于V形切换至关重要，比典型的FLC更重要，因此该项目将提供对取向层-LC相互作用的更好理解。