Electrowetting display (EWD) has promising prospects in the electronic paper industry due to it having superior characteristics, such as the ability to provide a comfortable reading experience and quick response. However, in real applications, there are also problems related to dielectric deterioration, excess power consumption, optical instability and narrow color gamut etc. This paper reviewed the existing challenges and recent progress made in terms of improving the optical performance and reliability of EWD. First, the principle of electrowetting applied in small and confined configurations is introduced and the cause of the failure of the dielectric layer is analyzed. Then, the function of the pixel structures is described to avoid display defects. Next, electric signal modulations are compared in terms of achieving good image quality and optical stability. Lastly, the methods are presented for color panel realization. It was concluded that multi-layer dielectrics, three-dimensional pixel structures, proper electric frequency-and-amplitude modulation and an RGB color panel are expected to resolve the current limitations and contribute to designing advanced reflective displays.

Colorful electrowetting displays (EWD) present many challenges, such as scalability and electro-optical performance improvement (e.g., brightness, color gamut, and contrast ratio). The first full investigation of scalable fabrication and testing processes for multi-color segmented EWD with potentially unprecedented electro-optical performance is proposed. A three-layer architecture is employed to achieve colorful EWD, where the key components are three primary color layers (cyan, magenta, and yellow), switched independently. Unlike previous reports referred to herein, which used the same fabrication and testing processes for each layer, this architecture facilitates a uniform performance, improves yield, and simplifies the process for colorful EWD. With an aperture ratio greater than 80%, National Television Standards Committee (NTSC) color gamut area greater than 63%, switching speed lower than 12 ms, and DC driving voltage below 22V, the testing results of colorful EWD are proven successfully by using our proposed processes. The processes investigated in this paper have greatly improved efficiency, suitable for a high-volume of full-color EWD.

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.