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Dynamically tunable reflective structural colors are attractive for reflective displays (electronic paper). However, it is challenging to tune a thin layer of structural color across the full red-green-blue (RGB) basis set of colors at video rates and with long-term stability. In this work, this is achieved through a hybrid cavity built from metal-insulator-metal (MIM) "nanocaves" and an electrochromic polymer (PProDOTMe2 ). The reflective colors are modulated by electrochemically doping/dedoping the polymer. Compared with traditional subpixel-based systems, this hybrid structure provides high reflectivity (>40%) due to its "monopixel" nature and switches at video rates. The polymer bistability helps deliver ultralow power consumption (≈2.5 mW cm-2 ) for video display applications and negligible consumption (≈3 µW cm-2 ) for static images, compatible with fully photovoltaic powering. In addition, the color uniformity of the hybrid material is excellent (over cm-2 ) and the scalable fabrication enables large-area production.

Time-limited exposure of electrode-free optically rewritable electronic paper is essential for applications, but performance characteristics can be modest. In this study we investigate whether imag...

The possibility of actively controlling structural colors has recently attracted a lot of attention, in particular for new types of reflective displays (electronic paper). However, it has proven challenging to achieve good image quality in such devices, mainly because many subpixels are necessary and the semitransparent counter electrodes lower the total reflectance. Here we present an inorganic electrochromic nanostructure based on tungsten trioxide, gold, and a thin platinum mirror. The platinum reflector provides a wide color range and makes it possible to "reverse" the device design so that electrolyte and counter electrode can be placed behind the nanostructures with respect to the viewer. Importantly, this makes it possible to maintain high reflectance regardless of how the electrochemical cell is constructed. We show that our nanostructures clearly outperform the latest commercial color e-reader in terms of both color range and brightness.

This review examines the state of art in research aimed at the development of electronic paper (electronic ink, e-ink), namely, the general principles to design a colloidal system with desired properties, having sedimentation and aggregate stability, consisting of a dispersed phase (reverse-micellar nanoreactors based on pigments) and a dispersion phase (nonpolar solvent/surfactant). More specifically, the subject matters of the review are: general methods and approaches used in the synthesis and modification of colloidal pigment particles; the electrophoretic properties of various dispersion systems comprising these particles (one-, two-, and three-color e-inks), which depend on the size of modified pigments, their zeta potentials, electrophoretic mobility, the presence of surfactants, dispersants, and emulsifiers; the chemical, physicochemical, and physicomechanical methods for microencapsulation of ink dispersions; and methods for manufacturing electrophoretic cells, including those used in micron-level cell design.

Reflective liquid crystal displays are attracting attention as portable information systems because of zero- or extremely low power consumption. In this study, we deal with an electrode-free reflec...

Eco-friendly and cost-effective materials and processes to manufacture functional substrates are crucial to further advance the area of printed electronics. One potential key component in the printed electronics platform is an electrically functionalized paper, produced by simply mixing common cellulosic pulp fibers with high-performance electroactive materials. Herein, an electronic paper including nanographite has been prepared using a standardized and scalable papermaking technique. No retention aid was needed to achieve a conducting nanographite loading as high as 50 wt %. The spontaneous retention that provides the integrity and stability of the nanographite paper, likely originates partially from an observed water-stable adhesion of nanographite flakes onto the fiber surfaces. The resulting paper exhibits excellent electrical characteristics, such as an in-plane conductivity of 107 S/cm and an areal capacitance of 9.2 mF/cm(2), and was explored as the back-electrode in printed electrochromic displays. Funding Agencies|Digital Cellulose Centre, a competence center set up by the Swedish Innovation Agency VINNOVA; consortium of Swedish forest industries; Wallenberg Wood Science Center (Knut and Alice Wallenberg Foundation); VINNOVA "EPIC" projectVinnova [2017-05413]; Karl-Erik Onnesjo Foundation

The Taguchi method was used to optimize the stack structure of electronic paper displays. The falling ball experiment was performed to analyze the effect of various combinations of cover lenses, optically clear adhesives, and substrates on the impact strength of the module surfaces. The results revealed that the stack structure considerably improved the surface impact resistance. The combination of a glass substrate electronic paper display and a plastic cover lens achieved the highest surface impact resistance.

In this paper opto-electronic methods for adaptive camouflage for a soldier are presented. This work is part of the EU funded project ACAMSII, “Adaptive CAMouflage for the Soldier II”, a future soldier system to be developed and implemented that provides adaptive camouflage against all relevant sensor threats, ranging from visible to thermal IR and radar. The assessment of possible technologies for adaptation of the visual signature is presented and discussed. The three most promising technologies will be discussed in detail: LED, OLED and electronic paper. Concerning the optical properties this paper will focus mainly on single colours and intensities, not on pattern generation and evaluation. Optical properties like luminance and the impact of reflectance are studied and compared. Especially the appearance of LEDs embedded in a textile and the impact of reflected ambient light will be analyzed. A discussion of colour space properties as a function of illuminance and surrounding background textile is presented also. It turned out that OLED and electronic paper devices have considerable disadvantages compared to LEDs. Therefor LEDs are the most promising optoelectronic components to be used for adaptive camouflage in the visible spectral range. Concerning the NIR spectral range a discussion of the optical requirements and the application of NIR diodes in clothing will be presented also.

Reflective displays or “electronic paper” technologies provide a solution to the high energy consumption of emissive displays by simply utilizing ambient light. However, it has proven challenging to develop electronic paper with competitive image quality and video speed capabilities. Here, the first technology that provides video speed switching of structural colors with high contrast over the whole visible is shown. Importantly, this is achieved with a broadband‐absorbing polarization‐insensitive electrochromic polymer instead of liquid crystals, which makes it possible to maintain high reflectivity. It is shown that promoting electrophoretic ion transport (drift motion) improves the switch speed. In combination with new nanostructures that have high surface curvature, this enables video speed switching (20 ms) at high contrast (50% reflectivity change). A detailed analysis of the optical signal during switching shows that the polaron formation starts to obey first order reaction kinetics in the video speed regime. Additionally, the system still operates at ultralow power consumption during video speed switching (

Bistable electrowetting display (EWD) is a promising low-power electronic paper technology, where power is consumed only during the switching between two stable states; however, it is not required for state maintenance once switched. In this paper, a bistable electrowetting device with non-planar designed controlling electrodes is fabricated by a fully conventional photolithography process. The device has potential for video display applications with a controllable gray scale. The novel electrode design realizes a lower driving voltage and a higher contrast between two stable states than the EWDs with planar electrodes reported previously.

Electrochromic devices have many important commercial applications ranging from electronic paper like displays, antiglare rear-view mirrors in cars, to energy-saving smart windows in buildings. Monovalent ions such as H+, Li+, and Na+ are widely used as insertion ions in electrochromic devices, but they have limitations such as instability, high cost, and hard handling. The utilization of multivalent ions as insertion ions has been overlooked probably because of the strong electrostatic interactions between ions and intercalation framework as well as the resulted difficulties of intercalation.The bivalent cation, Mg2+, has been proved to be efficient electrochromic insertion ions for the electrochromic processes of the nonstoichiometric W18O49 nanowires. Using Mg2+ based aqueous electrolyte, the electrochromic W18O49 nanowires shows a short coloration/bleaching time of 2.7/3.6 s, and a high tinting productiveness of 116 cm2/c, together with excellent cyclic constancy. The utilization of bivalent Mg2+ as insertion ions will benefit electrochromic devices with low cost, high stability and simple operation.

In this study, we promote a new dye-doped nematic liquid crystal (DDNLC) microcapsules system sandwiched between two ITO substrates for making an electrochromic fabric coating with both low driving voltage and wide versatility. The effects of the dye dosage, particle size and shell thickness of microcapsules on the electro-optical properties of DDNLC microcapsules were systematically investigated. Results show that optical appearance of the optimized DDNLC microcapsules can be reversibly changed between transparent and colored states by switching on and off the direct-current power. Driving voltage, response time and delay time were close related to the particle size of DDNLC core in microcapsules, and an alignment model was used to calculate the geometric construction of the microcapsules. The proposed experimental results provide reliable simulations of the electro-optical properties of DDNLC microcapsules which showing great potential applications in a wide range of uses, such as electronic paper, military camouflage coating or intelligent flexible display fabric.

This paper presents a novel film type of flexible loudspeaker by ultra-thin piezoelectric PZT/Si bare chip integrated on flexible film substrate. The device is designed to operate without a closed membrane offering significant improvements with respect to manufacturability. We have revealed that a fully audible sound pressure level of around 40 dB at 6500 Hz was generated for a film with an ultrathin PZT/Si chip 1 × 5 mm2 in size. This technology is expected to be applied as electronic parts for surround or flexible parametric speakers for electronic paper and smartphones.

Electrokinetic displays are among the most important display technologies because of their low power consumption, wide viewing angle, and outdoor readability. As a result, they are regarded as excellent candidates for electronic paper. These types of displays are based on the controlled movement of charged pigment particles in a non-polar liquid under the influence of an electric field. Free charges practically do not exist in nonpolar colloids due to their low dielectric constant. However, the addition of a surfactant to non-polar colloids often leads to considerable charge-induced effects, such as increased electrical conductivity and particle stabilization. In this project, we aim to develop a novel electrokinetically driven display. An unprecedented display device is proposed, based on the concerted action of electro-osmosis and electrophoresis in a non-polar fluid. This method could reduce the switching time required to display information, and extend the applications of electrokinetic displays, enabling increased video speed and full color in the future.

Paper has many uses such as in writing, printing, packaging, paper money, cheques voucher, cleaning, as construction materials, etc. Based on its applications, paper may be characterized as bank paper, book paper, bond paper, construction paper, cotton paper, electronic paper, photo paper, wallpaper, etc. The popular raw materials used to make paper are esparto-grass, straw, wood, flax, hemp, jute and rags-cotton and linen. The paper manufacturing process consists of two main stages: pulp making and conversion of pulp into paper. The process of producing pulp may be done by chemical or mechanical means, or by a combination of both depending on the nature of raw material used and the end application of the produced paper. Three operations are required to manufacture paper that are beating, conversion of pulp to paper and finishing. This chapter comprehensively covers the types of papers, their uses, raw materials and their manufacturing processes. Pulp and paper mills have adverse effects on the environment such as depletion of forest covers, and chemical pollution caused by liquid effluent discharges, solid wastes and air emissions from particulates, H2S, NOx, SOx. These have been covered in detail including means to reduce their emissions and treatment methods.

A new system of yolk-shell microcapsules containing two types of dye-doped liquid crystals was prepared via seed emulsion polymerization in which the synthetic process was mimicking plant respiration. The resulting system demonstrated reversible low voltage-driven switching between multispectral colored and transparent states. Moreover, wearable multicolor electrochromic fibers based on calcium alginate were produced via wet spinning to expand the application of yolk-shell dye-doped liquid crystal microcapsules. In addition to its long-term optical stability, the proposed cells and fibers also have satisfactory driving voltage values of color change (4.8 and 9.0 V), which are far lower than the human body safety voltage (12 V). We believe that the prepared microcapsules and fibers are potentially widely applicable in smart windows, electronic paper, and military camouflage clothing.

Electronic paper (i.e., e-paper) is a display technology that aims to imitate and substitute the conventional paper. Previous studies of e-paper mainly focus on evaluating or making practical use of its readability. However, there is little research to explore the potential of e-paper on input-oriented applications. In this paper, we introduce a document composition system named SwiftPad for e-paper. Specifically, SwiftPad renovates the famous TEX typesetting system, enabling users to compose high typographic quality documents on e-paper in a WYSIWYG (what you see is what you get), offline-first, and collaborative fashion. Building such a system on resource-constrained e-paper with low screen refresh rate creates unique challenges. In this paper, we identity these challenges and provides workable solutions. We also provide a preliminary evaluation of the new system.

Electronic paper is now closer than ever to changing the way we read, write, and study. This was hailed as a revolution so profound that some see it as second only to the invention of the printing press in the 15th century. In this study, four analytical methods, which included statistical analysis, technology decomposition, multistage technological evolution and growth potential analysis were used. Results showed that technological research on business has great potential for development and vast market, and it would be another 16 years before the limit could be reached for patents. A great deal of technology breakthrough has been achieved during 1992 and 2012. The four major countries for printed electronic paper development are Japan, USA, South Korea and China. However, China has a gap compared with other countries, as the key technology was held by large enterprises. The apparatus for printed electronic paper has been the major focus in China. The key point for research on printed electronic paper was focused on devices for presentation and light emission, and related semiconductor devices.

Partially addressable technology to realize a colorized image onto a glass substrate or plastic film in reflective electronic paper display is accomplished by the particle-moving method. This image panel includes upper and lower substrates with cells surrounded by rib patterns and filled with charged color particles. Mold substrate is prepared with the same condition as that of the lower substrate. The electric field between the mold and upper/lower substrates is used in this study, along with the image force of the conductive electrode. This addressable technology can be easily applied to any image panel, including transparent film. The feasibility of this technology is shown as a resultant reflective display panel with its fabrication process. We also ascertain that partially-addressed particles with a two-contrast color image are transferred from the mold substrate to the upper substrate of the panel via the particle-moving method.

A multi-functional electrochromic material which modulates light over a wide spectral range and stores electrical energy is an intriguing substance, which would lead to a variety of novel applications, such as smart windows for energy-efficient buildings, solar power storage, nonemissive displays, electronic paper, optoelectronic switches, and variable-reflectance mirrors/surfaces. Developing such a versatile material entails merging the electrochromic phenomenon with electrical-chemical energy conversions in an electrochromic-battery platform. However, the challenges related to transition metal oxide electrochromic-batteries include poor energy storage, low optical contrast, and high fabrication cost. Here, we demonstrate the synthesis of aqueous nanocrystalline colloidal molybdenum oxide in a matrix of tungsten molybdenum oxide (MoO3-W0.71Mo0.29O3) for solution-processed fully reversible switching electrochromic-battery electrodes. The hybrid material exhibits both 50% optical contrast modulation over a wide optical bandwidth and an improved Columbic efficiency. An 8 × 8 cm2 energy storing smart (ESS) window is assembled to demonstrate a functional prototype that can power an LED for more than 10 min when charged under −2.5 V for 1 min. The enhanced electrochromic performance, high energy storage capacity, simple solution processability, versatility for large area fabrication, and low cost make this nanocrystalline MoO3-W.71Mo.29O3 composite a promising material with the potential to be deployed ubiquitously in energy-efficient smart window architectures.

The electrophoretic display (EPD) is the main solution to electronic papers, but most of them can display the image or text in black and white particles only. The users may prefer the EPD showing multiple colors rather than the black/white content only. In this paper, we introduce the driving system for a color EPD, which is composed of three kinds of particles. The system aims at optimizing the visual quality based on a new driving waveform by equipping with an optimization method for color and tone reproduction. The experimental result shows that the proposed EPD driving system can display three-color pictures with promising visual quality.

Light-reflecting characteristics play a crucial role in optically rewritable liquid crystal display (electronic paper). By using a special optimizer software, light-reflecting characteristics of the twisted nematic cell were calculated. The achieved values of the normalized reflection coefficients range within ∼ 0.03 - 0.43, which is comparable or better than other commercial technologies. The calculated contrast ratio of the device is 10 : 1. A 2D image, which can be displayed on the electronic paper was obtained. Comparison of the simulated background color and contrast ratio is very similar with the results, which were obtained in experimental cells of other studies. Our calculations indicate that angular dependence of the reflectance coefficient is almost uniform within a wide range of viewing angles.

In our current world, active display technology creates a glut of energy demand to meet its illumination needs. This demand can be stymied by using reflective display technologies that require no active illumination, with some examples including: electronic paper using electrophoretic motion of ink particles, electrowetting of water/oil droplets, and interferometric modulators, all of which have been commercialized. However, due to the lack of active light sources, it is difficult to implement these reflective display technologies in low light environments (e.g. nighttime display). In this work, we report an experimental observation of multiple concentric circular rainbows from reflective microscale concave interfaces (MCIs), which are introduced by the reflection of optical rays within a polymer-embedded microsphere. Exit rays from a single edge and opposite edges will introduce completely different interference mechanisms depending on the illumination and observation conditions, which will result in different angle-dependent colors. By clarifying the mechanism behind this coloration phenomenon, as well as quantitatively mapping the generated color, the implementation of the MCI in smart signs and pixelated displays are demonstrated, showing angle-dependent color-changing reflected images that can be observed over a wide spatial angle range. This structural material will serve as a building block for the development of new platforms for light-matter interactions, on-chip sensors, anti-counterfeiting tools, and passive and smart color reflective displays. Intriguingly, we also demonstrate a smart MCI traffic sign for both visible and infrared wavelengths that will introduce extra signals for pattern and image recognition in order to enhance the safety of future autopilot/autonomous systems.

Background Display signage is ubiquitous and essential in hospitals to serve several clerical, operational, and clinical functions, including displaying notices, providing directions, and presenting clinical information. These functions improve efficiency and patient engagement, reduce errors, and enhance the continuity of care. Over time, signage has evolved from analog approaches such as whiteboards and handwritten notices to digital displays such as liquid crystal displays, light emitting diodes, and, now, electronic ink displays. Electronic ink displays are paper-like displays that are not backlit and show content by aligning microencapsulated color beads in response to an applied electric current. Power is only required to generate content and not to retain it. These displays are very readable, with low eye strain; minimize the emission of blue light; require minimal power; and can be driven by several data sources, ranging from virtual servers to electronic health record systems. These attributes make adapting electronic ink displays to hospitals an ideal use case. Objective In this paper, we aimed to outline the use of signage and displays in hospitals with a focus on electronic ink displays. We aimed to assess the advantages and limitations of using these displays in hospitals and outline the various public-facing and patient-facing applications of electronic ink displays. Finally, we aimed to discuss the technological considerations and an implementation framework that must be followed when adopting and deploying electronic ink displays. Methods The public-facing applications of electronic ink displays include signage and way-finders, timetables for shared workspaces, and noticeboards and bulletin boards. The clinical display applications may be smaller form factors such as door signs or bedside cards. The larger, ≥40-inch form factors may be used within patient rooms or at clinical command centers as a digital whiteboard to display general information, patient and clinician information, and care plans. In all these applications, such displays could replace analog whiteboards, noticeboards, and even other digital screens. Results We are conducting pilot research projects to delineate best use cases and practices in adopting electronic ink displays in clinical settings. This will entail liaising with key stakeholders, gathering objective logistical and feasibility data, and, ultimately, quantifying and describing the effect on clinical care and patient satisfaction. Conclusions There are several use cases in a clinical setting that may lend themselves perfectly to electronic ink display use. The main considerations to be studied in this adoption are network connectivity, content management, privacy and security robustness, and detailed comparison with existing modalities. Electronic ink displays offer a superior opportunity to future-proof existing practices. There is a need for theoretical considerations and real-world testing to determine if the advantages outweigh the limitations of electronic ink displays.

This paper presents the integration process of an ultra-thin PZT/Si chip on paper and that it functions as a simple speaker by applying a voltage in the audible frequency range. The PZT/Si chip used is only 5-μm-thick, so it does not interfere with the flexibility of the substrate, and it can be integrated on paper because it does not use a high-temperature process in the electrode connection process. We have revealed that a paper with an ultra-thin PZT/Si chip of only 1 × 5 mm2 in size generates a fully audible sound pressure level (SPL) of about 40 dB. It was rounded to a radius of curvature of 1 cm without breaking. The overall SPL was about the same even when the paper substrate dimension was reduced to 50 mm square. This technology is expected to be applied to electronic components such as surround speakers or haptics in electronic paper.

In this study, we implemented a micro-encapsulated CLC electronic paper that is optically addressed and electrically erasable. The mechanism that forms spot diameters on the CLC films is discussed and verified through various experimental parameters, including the thickness of CLCs and Poly(2,3-dihydrothieno-1,4-dioxin)-poly(styrenesulfonate) (PEDOT:PSS), pump intensity, and pumping time. The opto-thermal effect, brought on by the PEDOT:PSS absorbing layer, causes the spot diameters on the cholesteric liquid crystal thin films to vary. According to our results, the spot diameter is larger for a sample with a thinner cholesteric liquid crystal layer with the same excitation conditions and same thickness of the PEDOT layer. The spot diameter is also larger for a sample with a thicker PEDOT under the same excitation conditions and same thickness of the cholesteric liquid crystal layer. We proposed a simple heat-conducting model to explain the experimental results, which qualitatively agree with this theoretical model.

Plasmonic color generation offers several advantages but is also limited by the cost and availability of noble metals like gold. In this work, we present color-tunable metasurfaces with high chromaticity and reflectivity consisting of an aluminum mirror, a dielectric spacer, and a plasmonic nanohole array in copper. Copper is shown to be an excellent alternative to gold when properly protected from oxidation and makes it possible to generate a wide RGB gamut covering 27% of the standard RGB. By patterning the metasurfaces into microscale pixel triplets, color photos can be well reproduced with high resolution over wafer-sized areas. Further, we demonstrate active modulation of the reflected intensity using an electrochromic conductive polymer deposited on top of the nanostructures by screen printing. This technology opens up for ultrathin and flexible reflective displays in full color, that is, plasmonic electronic paper, compatible with large-scale sustainable production. Funding agencies: Swedish Foundation for Strategic Research [RMA11-0037]; Wenner-Gren Foundations; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009 00971]; Chalmers Nanoscience and Nanotechnology Area of

Janus particles are colloidal particles with more than a single type of surface chemistry or composition, ranging in size from hundreds of nanometers to a few micrometers. Like traditional colloids, they are large enough to be observed under optical microscopy in real time and small enough to diffuse by Brownian motion, but their interesting and useful new properties of directional interaction bring new research opportunities to the fields of soft matter and fundamental materials research as well as to applications in other disciplines and in technologies such as electronic paper and other multiphase engineering. In this review, a variety of methods that have been used to synthesize Janus particles are introduced. Following this, we summarize the use of Janus particles as basic units that assemble into novel structures and tune important material properties. The concluding sections highlight some of the technological applications, including recent progress in using Janus particles as microprobes, micromotors, electronic paper, and solid surfactants.

Electronic paper (e-paper) is a display technology that aims to imitate conventional paper. Currently most e-paper applications on handheld devices are restricted to digital book readers. Few studies explore the potential of e-paper on input oriented applications. In this paper, we introduce a novel e-paper application PaperWork, which allows users to offload their commonly used office applications from a PC to an e-paper device remotely. There are considerable challenges when building a system for a resource constrained e-paper device which we will highlight in this work. In addition to presenting a new e-paper system we also conduct a usability study of this system.

The purpose of this study is to explore the effect of display type, reading content, and background music on accuracy, change of critical fusion frequency (CFF) and subjective visual fatigue while performing a reading comprehension task on mass rapid transit (MRT). Thirty-two participants were recruited in a three-way mixed factorial experiment to investigate the influence of three types of display (liquid crystal display, electronic paper display, and plain paper), three types of reading content (science, literature, and magazine) and four types of background music (none, light music, pop music and heavy metal music). The results showed that display type was significant in all indices, where electronic paper displays and plain papers showed the better accuracy and lower change of CFF than liquid crystal displays. Plain papers demonstrated the lowest subjective visual fatigue. The results also indicated that reading content was significant on accuracy and subjective visual fatigue, where reading comprehension was better with magazines than with science- and literary-related texts. The results further demonstrated that background music was significant on subjective visual fatigue, where heavy metal music resulted in the greater visual fatigue than the three other kinds of music. Based on the results of this study, reading paper magazines and avoiding noisy music will lead to the lowest level of visual fatigue and, thus, enhance Chinese comprehension on MRT. Participants who are used to listening to music should be included as a test group in future studies. Relevance to industry This study provides suggestions for using suitable displays while reading on MRT. This information could serve as a reference for mobile display manufacturers in designing their future products.

The aim of this study was to understand to what extent people can read e-paper devices under various conditions of ambient illuminance that can occur indoors. In this study, 110 young to elderly subjects participated in an experiment to evaluate the effects of 14 different levels of ambient lighting on their reading from three different electronic devises and paper text. The participants were asked to undergo a timed read task and then to evaluate the readability of two eReader devices (a regular electronic display and one with a front light) in comparison with a backlit liquid crystal device and conventional paper text. The results indicated that backlit and front lit devices are easier to read at less than 200 lx and the reflective device is easier to read at levels above 500 lx.

Direct synthesis of charged hybrid particles in non-polar media has not been widely described in the literature but can lead to many applications such as electrophoretic displays. In this work, we propose a way to synthesize charged hybrid particles within the electrophoretic medium (Toluene or Isopar G) in the presence or not of additives (Charge Control Agent, CCA). The particles synthesis was performed by Nitroxide-mediated Radical Polymerization (NMRP) via dispersion polymerization in aliphatic hydrocarbon solvents leading to stable chargeable particles with a good size control. Hybrid particles are successfully charged by reaction with functional monomers or addition of CCA to obtain electrophoretic particles. The performance of a dual-color red/white ink in a display was demonstrated with a test-cell. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 338–348

Electrochromism, phenomenon of reversible color change induced by electrochemical redox reactions, is one of the prime candidates for full-color electronic paper. Recently, we reported Ag-deposition based multicolor electrochromic device showing color change between three primary colors of cyan, magenta, and yellow. These observed spectra include both absorbing and reflectance components. Therefore, it is necessary to separate these components in order to analyze coloration mechanism of the device. In this paper, coloration mechanisms of Ag deposition-based multicolor electrochromic device were investigated in terms of measurement of the actual absorption and actual reflection of the device. Morphologies of the deposited Ag nanoparticles were also investigated by FE-SEM, and then relationship between optical properties and deposited Ag morphologies was examined. As the results, color appearances of magenta and yellow state of the device were mainly dominated by absorption component of localized surface plasmon resonance of the deposited Ag nanoparticles. On the other hand, cyan state of the device was based on absorption as well as reflection component induced by thin film structure of the Ag deposit.

This study sought to verify the readability of e-paper devices under various conditions. The experimental conditions included various stages of illuminance, different font sizes, and different contrasts. More than 100 participants participated in the experiments from the young to the elderly. The subjects read and compared the e-paper, backlit LCD, and conventional paper under the various conditions.