Alignment treatments for surface stabilised ferroelectric liquid crystals

The alignment characteristics for a range of Sc materials are reported. Different types of polymer have been used as the aligning agent and various processing techniques of these polymers have been studied. A comparison has been made between three polymers; PVA polyimide and Nylon 6. In each case the alignment was assessed with the rubbing directions orientated parallel, antiparallel and with only one surface rubbed. The results show that in some cases, there must be a surface pretilt of the director in SSFLCD. Different thermal treatments of polyimide can vary this surface pretilt angle, and the effects of this have been studied. In addition, a novel hybrid alignment is presented. One surface is coated with rubbed nylon 6 to produce a homogeneous alignment and the other surface is coated with a polysilane to produce homeotropic alignment. Good alignment can be obtained using this technique and the bistability is always asymmetrical.