The alignment of liquid crystals by grooved substrates is still not well understood at the structural molecular level. This problem is important both fundamentally as well as technologically. The increased use of microarchitectural devices makes it imperative to obtain a better understanding of the structure of the LC-substrate interfacial region, how it is affected by the type of substrate preparation and how it affects the bulk of the LC film. We propose to study the evolution of structure ordering of smectic LC's deposited on grated substrates on grated substrates as a function of film depth and film thickness. The substrates consist of photolithographed gratings whose period and depth can be changed in a controlled manner. We use the X-ray glancing angle technique to characterize quantitatively the LC structure evolution. This study provide detailed information on the behavior of LC films between two disimilar, competing interfaces. It will have considerable impact on the improved implementation of LC films for applications, involving both disimilar as well as symmetrical surfaces.

Agency
National Science Foundation (NSF)
Institute
Division of Electrical, Communications and Cyber Systems (ECCS)
Application #
9201986
Program Officer
Marvin H. White
Project Start
Project End
Budget Start
1992-08-15
Budget End
1997-01-31
Support Year
Fiscal Year
1992
Total Cost
$275,000
Indirect Cost
Name
University of Pennsylvania
Department
Type
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104