Microfluidic multicolor display by juxtapositional color mixing with a pattern of primary color pixels

This paper describes a microfluidic multicolor display utilizing juxtapositional color mixing of pixels. Our display has a 14 × 14 array of pixels (2.5 mm in pixel diameter, 8.46 ppi) on the display surface where multicolor is expressed by controlling the pattern of the four primary color inks (cyan (C), magenta (M), yellow (Y), and black (= key plate, K)) that fill the pixels. The microfluidic display has a three-layer structure composed of a top layer with pixels for displaying images, a middle layer that serves as a background screen, and a bottom layer with microchannels that connect the pixels. In order to express multicolor by combining CMYK primary colors, we optimized the concentration of the inks used as the primary colors. By designing patterns of pixels filled with CMYK ink, color gradations and multicolor images were displayed on our display. The proposed microfluidic display could be applied to eye-friendly and low-energy-consumption flexible display applications including multi-purpose sign boards used in outdoors, wearing objects, and exterior/interior of vehicles and architects.

The Influence of Age and Oral Health on Taste Perception in Older Adults: A Case-Control Study

Declining gustatory function, nutrition, and oral health are important elements of health in older adults that can affect the aging process. The aim of the present work was to investigate the effect of age and oral status on taste discrimination in two different groups of elderly subjects living either in an Italian residential institution (TG) or in the community (CG). A total of 90 subjects were enrolled in the study (58 CG vs. 32 TG). Masticatory performance (MP) was assessed using the two-color mixing ability test. Taste function was evaluated using cotton pads soaked with six taste stimuli (salty, acid, sweet, bitter, fat and water). A positive correlation between age and missing teeth (r = 0.51, C.I. [0.33; 0.65], p < 0.0001), and a negative correlation between age and MP (r = −0.39, C.I. [−0.56; −0.20], p < 0.001) were found. Moreover, significant differences for salty taste, between TG and CG were detected (p < 0.05). Significant differences in bitter taste sensitivity between subjects wearing removable and non-removable prosthesis were also determined (p < 0.05). In addition, significant gender differences and between males in TG and CG were identified (p < 0.05). The best understanding of the relationship between MP, taste sensitivity, and nutritional factors is a necessary criterion for the development of new therapeutic strategies to address more effectively the problems associated with malnutrition in elderly subjects.

Color Schemes for Training Artists

The aim of the didactics of color is to create a connection, a state of harmony between the observable color and color which is created. This objective unfolds in the teaching methods employed. On one hand, analytical observation must be taught, allowing the gaze to distinguish different shades of color, to organize hierarchically levels of light and darkness and to evaluate subtleties in the saturation of hues. On the other hand, rigorous instruction in color mixing must ensure that the observable color, that is, the desired color, can be approached in an intuitive and precise way. In this article, the authors discuss the difficulties faced teaching color to student artists and how digital tools can be used for training the concept of observation and the analysis of color. These tools allow color schemes to be created. Here the authors discuss how these tools can be applied, based on the experience obtained in introductory painting classes involving students from the University of Salamanca.

Comparative study of the illumination effect on the appearances of woven fabrics composed of single and multiple colors of yarns

Color has been strategically used to attract consumers in the textile and clothing industry, and yarn color mixing is one of the most typical methods of imparting color to textile products. However, the fact that color appears different depending on the illumination has concerned textile designers and sellers at the point of color communication and sale. This study quantitatively analyzed how the color appearance of woven fabrics composed of single and multiple colors of yarns changes under a broad spectrum of illumination conditions. The lightness, chroma, and hue appearance values of 36 chromatic fabrics, in which red, yellow, green, and blue yarns were woven together, under 16 different illumination conditions were calculated. For the illumination conditions, correlated color temperatures (CCTs) of 2700, 4000, 5000, and 6500 K and luminance of 100, 1000, 4000, and 8000 cd/m2 were employed. The color appearance values of fabrics under the 16 light sources were compared with each other and also with their true physical colors. It was observed that the ranges of the varying lightness, chroma, and hue appearances of fabrics ranged up to 8.49, 16.24, and 27.04, respectively, indicating the huge effect of illumination on color appearance changes. In particular, the lower CCT of light sources induced the larger lightness appearance changes of fabrics from their actual physical colors. It was also found that the magnitudes of the color appearance changes of fabrics induced by light sources differed significantly according to the number of yarn colors and the overall colorimetric properties of the fabrics.