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.

Industrialization of electrofluidic devices requires both high performance coating laminates and efficient material utilization on large area substrates. Here we show that screen printing can be effectively used to provide homogeneous pin-hole free patterned amorphous fluoropolymer dielectric layers to provide both the insulating and fluidic reversibility required for devices. Subsequently, we over-coat photoresist using slit coating on this normally extremely hydrophobic layer. In this way, we are able to pattern the photoresist by conventional lithography to provide the chemical contrast required for liquids dosing by self-assembly and highly-reversible electrofluidic switching. Materials, interfacial chemistry, and processing all contribute to the provision of the required engineered substrate properties. Coating homogeneity as characterized by metrology and device performance data are used to validate the methodology, which is well-suited for transfer to high volume production in existing LCD cell-making facilities.

Electrowetting is a highly recognized way to control droplet movement on a solid surface and induce motion in the oil/water interface. It is still challenging to manipulate liquid/liquid interface dynamics due to the electro‐capillary instability caused by the electric field in the electrowetting system. Here a dielectric bridge is induced near the oil/water interface by constructing a conductive micropillar (CMP) directly on the hydrophobic surface in an electrowetting system. The CMP height can be adjusted by regulating the wettability of the hydrophobic surface. The electric‐field gradient induced by CMP can precisely control the rupture position and guide the contraction direction of the oil film. For application, the CMPs are added in the full‐color electrowetting display panel, and the average transmittance can increase 25% at white state due to the consistent oil contract direction. The rupture voltage is reduced, and the response time of the electrowetting display is also improved. The COMSOL simulation results are consistent with experimental results indicating the oil rupture position is controlled by the electric field strength. Combing with program patterning, the authors demonstrate a new display function in an unpatterned indium‐tin oxide‐based electrowetting display. These findings will benefit most switchable electrofluidic applications and devices with two‐phase liquid.