A full description of a scalable microfabrication process for arrayed electrowetting microprisms

Most electrowetting and liquid crystal optical devices are created by standard planar microfabrication. Arrayed electrowetting microprisms are a newer approach that offers unique performance, but which requires a challenging non-planar microfabrication process. This paper reviews a full description of a scalable fabrication process for an ∼1500 element array of ∼150 μm size electrowetting microprisms. The description includes creation of high aspect-ratio sidewalls, using a conventional i-line mask aligner to vertically pattern electrodes, conformal hydrophobic dielectric deposition, self-assembled and volume-controlled liquid dosing and module sealing. Also presented is a theoretical model which explores the resolution limits for vertically patterned electrodes. In addition to creating a first-generation fabrication process for arrayed electrowetting microprisms, this work may be further useful to investigators seeking methods of forming 3D arrayed electro-optic, electro-chemical or electro-mechanical devices. (Some figures in this article are in colour only in the electronic version)