Electro-optically addressable and rewritable transparent liquid crystal bistable waveguide display devices

Soft functional materials are in high demand to develop novel devices with excellent dynamic performances because they respond to specific stimuli with distinct functions. Here, we have examined sodium dodecyl sulfonate (SDS) ions doped into negative cholesteric liquid crystals (CLCs), employing an optically sensitive poly(N-vinyl carbazole) (PVK) film on ITO substrates for demonstrating a bistable light waveguide display device. The coated PVK film has the potential to block direct current (DC) electric fields and transform an insulator into a conductor when exposed to suitable ultraviolet (UV) stimuli, thus achieving pattern-addressing through the utilization of dynamic scattering of liquid crystals (LCs). Hence, the sample exhibits text pattern scattering and remains transparent under patterned UV stimuli. Initially, an external stimulus DC field was applied to the CLC cell to switch the planar textures in the region shining with UV light to focal conic textures that remain prolonged even after stimulus removal. Then, we examine the novel concept of a voltage-free “remote writing display” using transparent bistable waveguides displays by edge-lit white LED stimuli. Such advanced transparent displays offer robust stability, manufacturability, and cost-effectiveness for various applications in different environments and industries, such as automotive, e-paper, and augmented reality devices.