Abstract
In this review we describe the reversible photoalignment effect imposed on the director in nematic liquid crystals that provides an approach for fabrication of advanced optically addressed devices. Several new concepts have been developed to render photosensitive materials during the past decade. Functional soft azo dye compounds exhibiting distinct functionalities in response to polarized light are highly desirable for fabrication of optically rewritable electronic paper. An optically rewritable element base using simple and inexpensive materials can potentially enable the development of novel environmentally friendly, paper-like gadgets with improved functionality over regular electronic paper. We argue that an optically rewritable technique is relevant for some applications, where conventional paper might be irrelevant. In particular, we have tested and discussed several techniques of color and 3D image formation. This strategy for fabrication of novel devices offers versatile methods for visualization. We also show that the intensity modulation of the irradiation light has a potential to generate improved grayscale visualization. This principle is based on the statistical distribution control of photosensitive azo dye molecules, driven by the incident polarized light. Additionally, we discuss the functional characteristics of the developed prototypes.
Highlights
Publisher’s Note: MDPI stays neutralFirst attempts in reading and writing the effects of liquid crystal displays assumed electric-field-induced reorientation of director for image formation (e.g., [1,2])
Reflective displays show the designed information by manipulating the intensity of the reflected ambient light through microfluidic behavior in pixels driven by electrophoresis, electrowetting or electromechanical forces. Such displays are used in electronic papers, security films, calculators and other devices
Today, when most people think about electronic paper, they consider products containing electrophoretic display technology, which is known as E-Ink [3]
Summary
First attempts in reading and writing the effects of liquid crystal displays assumed electric-field-induced reorientation of director for image formation (e.g., [1,2]). Reflective displays show the designed information by manipulating the intensity of the reflected ambient light through microfluidic behavior in pixels driven by electrophoresis, electrowetting or electromechanical forces Such displays are used in electronic papers, security films, calculators and other devices. Optically rewritable electronic paper (ORW e-paper) is an electrode-free and optically addressed device with a grayscale capability, wide viewing angles and a contrast ratio of about 10:1 All these properties have been widely discussed in our previous reviews [7,8]. The colored particles either spread across the pixel or move out of sight altogether, making it possible to render different colors by controlling the number of colored particles shown [21] This technique is totally ambient light adaptive [22].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
