Electrophoretic Inks with Structural Color

1236086PI: dufresne电泳显示基于带电胶体颜料消耗的能量远远少于传统背光液晶显示。事实上，一个设计良好的电泳显示与静态图像不消耗能量。这种节能源于两个重要因素。首先，电泳显示器是双稳态的，因此它们只在改变显示图像时消耗能量。其次，电泳显示器使用环境光，而不是内部光源。因此，电泳显示器是理想的阅读，标志和建筑应用。然而，这些显示器的主要限制是它们只能产生黑白图像。原则上，彩色图像可以创建从电泳显示通过使用彩色滤光片，如在液晶显示器，但这样的设备将是太暗的大多数应用。明亮的电泳显示器要求每个像素能够显示红色、绿色或蓝色。为了实现这一目标，该项目将创造具有结构色的电泳油墨。受鸟类羽毛中产生颜色的纳米结构的启发，这项工作将通过调整带电胶体粒子的间距来控制电泳油墨的颜色。粒子间距将由粒子间力和外加电场决定。因此，包含像素的油墨的颜色将随施加的电压而切换。为了实现这一目标，该项目需要解决胶体科学中的几个基本问题。首先，该研究将确定在非极性溶剂中产生带电悬浮液的一般原理和特定材料，这些悬浮液具有足够的短程顺序以产生结构颜色。其次，研究将表征外电场对这些悬浮液结构的影响。

1236086PI: DufresneElectrophoretic displays based on charged colloidal pigments consume far less energy than conventional back-lit liquid crystal displays. In fact, a well-designed electrophoretic display with a static image consumes no energy. This energy savings arises from two important factors. First, electrophoretic displays are bistable, so they consume energy only when changing the displayed image. Second, electrophoretic displays use ambient light, instead of internal light sources. Therefore, electrophoretic displays are ideal for reading, signage and architectural applications. However, the central limitation of these displays is that they only produce black and white images. In principle, color images can be created from electrophoretic displays through the use of colored filters, as in an LCD display, but such devices would be too dark for most applications. Bright electrophoretic displays would require each pixel to be able to display either red, green or blue. To achieve this, this project will create electrophoretic inks with structural color. Inspired by color-producing nanostructures in bird feathers, this work will control the color of electrophoretic inks by tuning the spacing of charged colloidal particles. The spacing will be determined by interparticle forces and external electric fields. Thus, the color of the ink containing pixel will be switchable with an applied voltage. To achieve this goal, this project will need to solve several fundamental problems in colloid science. First, the research will identify general principles and specific materials for creating charged suspensions in non-polar solvents with sufficient short-range order to produce structural colors. Second, the research will characterize the effect of external electric fields on the structure of these suspensions.