Single-substrate liquid-crystal displays by photo-enforced stratification

Data visualization plays a crucial role in our society, as illustrated by the many displays that surround us. In the future, displays may become even more pervasive, ranging from individually addressable image-rendering wall hangings to data displays integrated in clothes(1). Liquid-crystal displays (LCDs) provide most of the flat-panel displays currently used. To keep pace with the ever-increasing possibilities afforded by developments in information technology, we need to develop manufacturing processes that will make LCDs cheaper and larger, with more freedom in design. Existing batch processes for making and filling LCD cells(2,3) are relatively expensive, with size and shape limitations. Here we report a cost-effective, single-substrate technique in which a coated film is transformed into a polymer-covered liquid-crystal layer. This approach is based on photo-enforced stratification: a two-step photopolymerization-induced phase separation of a liquid-crystal blend and a polymer precursor. The process leads to the formation of micrometre-sized containers filled with a switchable liquid-crystal phase. In this way, displays can be produced on a variety of substrates using current coating technology. The developed process may be an important step towards new technologies such as 'display-on-anything' and 'paintable displays'.