Solvent-based paste extrusion solid freeforming

Solvent-based extrusion freeforming is capable of building complex ceramic 3D structures and can be used in the fabrication of hard and soft tissue scaffolds, photonic crystals for millimetre wave, ordered ceramic preforms for metal matrix composites, precise molten metal filters and potentially for terahertz bandgap metamaterials. This is a powder-based rapid prototyping process, the principle of which is the realization of liquid to solid transition through solvent evaporation in the presence of a binder. We describe the characteristics of pastes prepared from different powders, notably the rheological properties at different solvent fractions and illustrate some of the structures fabricated by this technique.