A full description of a simple and scalable fabrication process for electrowetting displays

Abstract

Electrowetting displays provide a high white state reflectance of >50% and have attracted substantial world-wide interest, yet are primarily an industrially led effort with few details on preferred materials and fabrication processes. Reported herein is the first complete description of the electrowetting display fabrication process. The description includes materials selection, purification and all fabrication steps from substrate selection to sealing. Challenging materials and fabrication processes include dielectric optimization, fluoropolymer selection, hydrophilic grid patterning, liquid dosing, dye purification and liquid ionic content. The process described herein has produced pixel arrays that were switched at <15 V on active-matrix backplanes, and which have individual sub-pixel areas of <50 × 150 μm 2 . The majority of fabrication processes can conform to liquid-crystal style manufacturing equipment, and therefore can be readily adopted by many display practitioners. Also presented are additional tips and techniques, such as controlling the onset of oil film break-up in an electrowetting display. This paper should enable anyone skilled in displays or microfabrication to quickly and successfully set up research and fabrication of electrowetting displays.

Experimental Validation of the Invariance of Electrowetting Contact Angle Saturation

“…The insulating fluid is an organic material just like many of the dielectrics used, and is in some cases exposed to similar electric fields at which electrical insulation fails. A strong 'relaxation' of the contact angle is often observed in electrowetting displays [19] and optics [20] when using insulating fluids that consist of molecules with a non-zero dipole moment such as chloronaphthalene, or that contain a polar additive in the fluid such as a dye or surfactant. In patent literature it has been suggested that polar molecules in the insulating fluid facilitate charge injection into the oil [21], because they show increased affinity for ions from the conductive fluid.…”

Nematic films at chemically structured surfaces

“…the case of tunable-focus liquid lenses [31], electrowetting displays [32,33], or responsive diffraction gratings [34][35][36][37]. In refs.…”

Principal Component Analysis of Multi-Pigment Scenario in Full-Color Electrophoretic Display

“…E-Paper is a direct view electronic display that is either bi-stable or nearly bi-stable with the benefit of extremely low power consumption. Generally, there are several scenarios to implement the bi-stability (or nearly bi-stability), including electrophoretic [1]- [7], electrofluidic [8], [9], bi-stable liquid crystal display (LCD) [10], [11], electrowetting [12], [13] and other emerging approaches [14]. Despite jeopardized by the great success of emissive displays and their accompanying PC devices, e-Paper still has potential to leverage its strongest advantages which emissive counterparts are hard to achieve, such as superior energy saving, fine contrast under sunlight, continuous roll-to-roll manufacturing, flexible format, or even paper-like reading comfort.…”