Manufacture of Regularly Shaped Polymer Cholesteric Liquid Crystal Flakes with a Mechanically Flexible Mold

Brief Description
Applications:
This invention relates to manufacturing micron-sized shaped flakes of plastic (flowable) material which have precise configurations, and particularly to making flakes of polymeric liquid crystal materials to be used in a host fluid in electrically addressable optical devices for information displays.

Advantages:
Micron sized PCLC flakes that are more regularly shaped behave with more uniform motion within an electro-optic cell. Current freeze fracture methods used to manufacture polymer cholestric liquid crystal flakes result in arbitrary shapes. This invention, however, uses mechanically flexible molds, photolithographically prepared on a plastic sheet. The molds are filled out with flowable material, which is then solidified by cooling or UV cross linking.  Subsequent deformation of the plastic sheet will release these uniformly shaped flakes.  The technique allows the production of thousands of square, rectangular, or diamond shaped flakes per day. These flakes have better surface quality, uniformity, and thickness than those commercially available and perform in a more predictable and uniform manner in an electro-optical device.
Patent Information:
Title Country Patent No. Issued Date
Method for Making Precisely Configured Flakes Useful in Optical Devices United States 7,238,316 7/3/2007
Category(s):
Materials
For Information, Contact:
Curtis Broadbent
Licensing Manager
University of Rochester
585.273.3250
curtic.broadbent@rochester.edu
Inventors:
Kenneth Marshall
Anka Trajkovska-Petkoska
Stephen Jacobs
Tanya Kosc
Keywords: