Multi-Configurations in Nematic Liquid Crystal Films: A Microrubbing Approach

ABSTRACT

We report a technique for the patterned alignment of liquid crystals on polyimide using microrubbing (μ-rubbing). Homeotropic polyimide was μ-rubbed with a metallic sphere 1 mm in diameter under a specified load of 150 grams. We observed that μ-rubbing induces a high pretilt planar alignment when homeotropic polyimide is used. Liquid crystal cells were constructed from two μ-rubbed polyimide substrates, whose rubbing directions are oriented orthogonal to each other. At the intersection points of two μ-rubbed lines, a twisted nematic configuration was observed. In the other sections of the sample, either a splay or homeotropic configuration is realized. A pretilt of 10° was measured in the μ-rubbed area. The electro-optical performances of the twisted nematic regions were also investigated.

Keywords:

• homeotropic
• liquid crystal displays
• microrubbing
• planar
• polyimide
• pretilt

Acknowledgments

Funding of this project was provided by Netherlands University Federation for International Collaboration (Nuffic). The author likes to thank Dr. Sunil K. Narayanankutty, Cochin University of Science and Technology, India, Pit Teunissen, Chris van Heesch, Peter Minten (GTD) at Eindhoven University of Technology for their support.

Notes

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