Flexible interconnected ceramic parts 3D printed by two-component material extrusion with water-soluble support structures

Material extrusion (MEX) of complex thermoplastic structures often depends on the reliable printing of a water-soluble support structure. The material of choice is typically polyvinyl alcohol (PVA), which is not used in ceramic MEX printing due to a limited printing compatibility with most ceramic feedstocks (poor layer adhesion). Herein, a new thermoplastic feedstock was developed as temporary support material on the basis of NaCl mixed with a commercial injection molding binder system. The NaCl feedstock is fully compatible for MEX printing with ceramic feedstocks and showed excellent printing properties and high green body strength. The support structure is mostly dissolved in water and the rest can be removed manually or during thermal debinding. The NaCl support material was used to print flexible Al2O3 samples with hinges or chainmail samples. This strategy is an attractive way to introduce additional functionality and new applications which were so far inaccessible to technical ceramics.