Use of polydimethylsiloxane thin film as vertical liquid crystal alignment layer

The possibility of the use of polydimethylsiloxane to align liquid crystals is studied. The polydimethylsiloxane thin films coated on glass substrates exhibit a very low surface free energy, and are found to be capable of vertical liquid crystal alignment. Comparing to thin films made using a typical polyimide polydimethylsiloxane films possess a more stable surface energetic state. The pretilt angle of the calamitic liquid crystal molecules sandwiched between the silicon elastomer thin films was virtually 90 degrees, and the molecular tilt can be maintained in a wide temperature range. Liquid crystal sandwiched between the silicon-based polymer thin films can operate in the in-plane-switching mode. (C) 2011 Elsevier B.V. All rights reserved.