Robocasting

Robocasting or Direct Ink Writing (DIW) is an additive manufacturing technique in which a filament of 'ink' is extruded from a nozzle, forming an object layer by layer. The technique was first developed in the United States in 1996 as a method to allow geometrically complex ceramic green bodies to be produced by additive manufacturing. In robocasting, a 3D CAD model is divided up into layers in a similar manner to other additive manufacturing techniques. A fluid (typically a ceramic slurry), referred to as an 'ink', is then extruded through a small nozzle as the nozzle's position is controlled, drawing out the shape of each layer of the CAD model. The ink exits the nozzle in a liquid-like state but retains its shape immediately, exploiting the rheological property of shear thinning. It is distinct from fused deposition modelling as it does not rely on the solidification or drying to retain its shape after extrusion.