Soft imprinting lithography for multi-domain alignment layers in liquid crystal devices

We describe molecular-scale soft nanoimprint lithographic replication of rubbed poly(dimethylsiloxane) (PDMS) substrates to form alignment layers for liquid crystal (LC) devices. Systematic studies of the surface relief morphology of the PDMS and molded structures in three different rubbing strength illustrate good lithographic fidelity down to relief heights of several nanometers, and with some capabilities at the level of 1 nm. Collective results of experiments for molds and molded materials and process conditions indicate that this molecular scale fidelity in replication can be used to produce surfaces that will effectively align LC molecules. It has been demonstrated that the PDMS nano groove pattern has a comparable influence on LC alignment to the conventional rubbing process. It has been also shown that the artificial topography of the line grooves on the conventionally PDMS surface has a significant influence on the anchoring stability of the LC molecules. # 2010 The Japan Society of Applied Physics.