Bistable alignment of nematic liquid crystals around microscopic posts

With conventional nematic liquid crystal displays there is only one orientation of the material that is stable without an applied field. In order to maintain an image the pixels have to be continually refreshed, placing an upper limit on the pixel count. Overcoming this requires having some memory within each pixel. To avoid putting an expensive transistor within every pixel one can design the display to be inherently bistable. Here we describe how micron-scale posts on a substrate can stabilize multiple orientations. By engineering the posts we have demonstrated a bistable display with long term memory.