"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
This Small Business Technology Transfer (STTR) Phase II project will enable the widespread use of ferroelectric liquid crystal (FLC) electro-optic devices, leading to a new generation of displays that have greater speed, higher resolution and lower power consumption than today's liquid crystals displays (LCDs), which use nematic LCs. A proprietary family of additives, "polymer dopants" demonstrated in Phase I, overcomes the main technical obstacles to large-scale application of FLC devices: manufacturing and stabilizing properly aligned cells. The proposed work will develop FLC-polymer materials that expedite processing and increase the yield of well-aligned FLC cells. In Phase I the team: 1) Identified side-group liquid crystal polymers that dissolve in FLC. , 2) Showed that the FLC-polymer mixtures retain fast electro-optic (EO) responses3) Demonstrated that the FLC-polymer mixtures robustly and rapidly adopt the proper alignment, giving bistable switching that is elusive in the FLC alone. In Phase II the team will establish the structure-activity relationships for polymer dopants. It will optimize the FLC-polymer mixtures to establish reliable processes to produce well aligned FLC cells in high yield at high production rates.
Approximately 2x109 small flat panel displays are used annually in cell phones, PDAs, iPods, etc. Currently, nematic LCDs overwhelmingly dominate this market $20 billion/year in LCDs, manufactured using $350 million/year of LC materials. The additives developed in this project will allow FLCs to be processed into displays in this size range, providing a step-change in resolution and speed in LCDs. This will lay the foundation for moving FLCs into LCD TVs ($86.3 billion/year market in 2008, growing rapidly). Enabling commercial production of FLC displays 10 cm and up could revolutionize display technology and potentially fuel the growth of display manufacturers in the U.S. Scientifically, solutions of polymers in FLCs represent a nascent class of materials that has hardly been explored. This project is at the cutting edge of experimental research in LCs, providing the first glimpse into the consequences of orientational coupling in chiral smectic LCs.
The objectives proposed by the team for Phase II included the establishment of a structure-activity relationship for polymer dopants optimized to produce reliable processes for the manufacture of well-aligned FLC cells in high yield and at high production rates. During our research, the team: 1) Identified side-group liquid crystal polymers that dissolve in its FLC host 2) Showed that the FLC-polymer mixtures retain their fast electro-optic (EO) response 3) Demonstrated that in certain select FLC-polymer mixtures, is possible to induce bistable behavior from a previously monostable FLC mixture. The team found that their FLC-polymer dopant additives effectively suppressed light-leaking defects at very low concentrations. This solves a long standing problem with attempts at manufacture of large size FLC display devices, which require the construction of properly aligned, high contrast LC panels and stabilizing its proper alignment for the life of the device. The size and yield of FLC panels were currently limited by the formation of "zig-zag defects" which result in low contrast and degrade image quality. The addition of only 1% FLC polymer dopant developed during this Phase II effort results in the complete suppression of zig-zag defects, as compared to an un-doped FLC cell, as shown in figure 1. FLC displays are limited to the manufacture of displays less than one inch in size because zig-zag defects become markedly worse as display size increases. With the utilization of these novel FLC-polymer additives developed under Phase II, the manufacture of large area FLC displays is possible for the first time. In addition, the faster switching speed that is inherent in FLC mode display, up to 100 times faster than the typical nematic based LCD, allows the use of time sequential color to generate full color in the display, eliminating color filters typically used in nematic displays, which are one of the most expensive components of today’s LCD. Another advantage of FLCs is its remarkably wide 180 degree viewing angle, that eliminates the need for expensive compensating films required in nematic displays to obtain an equivalent field of view. The additives developed in this project will allow FLCs to be processed into displays in this size range, providing a step-change in resolution and speed in LCDs. This will lay the foundation for moving FLCs into LCD TVs. Approximately 2 Billion small flat panel displays are used annually in cell phones, PDAs, iPods, etc. Currently, nematic LCDs overwhelmingly dominate this $137 Billion/year market in LCDs. Enabling commercial production of HDTV scale FLC displays could potentially revolutionize display technology.
