Inkjet printing of ceramic materials is a shaping process of interest for building micrometer-sized components. It consists of depositing droplets of colloidal inks according to a printing pattern designed to obtain a given final part. Improving the printed part properties, e.g., thermal or electrical, requires to tailor the printed material's local structure and orientation. Electric field is an efficient external stimulus to control particle orientation. A major challenge is to efficiently couple the effects of electric field and those of capillary, viscous, and evaporation phenomena occurring during inkjet printing. In this paper, the effect of an external electric field on the structuration of inkjet deposits is investigated. Suspensions of mica platelets dispersed in binary mixtures of chloroform and silicone oil are ejected on demand on a glass plate. An electric potential difference is applied by means of a set of electrodes below the glass substrate, separated by a small gap in order to maximize the electric field on the surface of the plate. A cartography of splat morphology and structuration for different inks as a function of applied field is performed. Promising experimental conditions display particle arrangement and limited splat deformation, whereas others lead to fingering. This paves the way to a novel additive shaping process by adding another smaller scale of structuration to inkjet printed parts.
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