Direct ink writing of ceramics: from fundamentals to industrial applications

Direct Ink Writing (DIW), a nozzle-based extrusion technique, has emerged as a versatile method for additive manufacturing of complex ceramic architectures. By formulating shear-thinning inks containing high solid loading of ceramic particles and suitable binders, DIW enables layer-by-layer deposition of 3D structures from microscale to large scale. This review synthesizes recent advances in DIW of ceramics, beginning with fundamental principles and technology evolution before exploring ink formulation strategies, rheological properties, and stabilization methods. Subsequently, printing hardware configurations, process parameters, and in situ monitoring techniques are examined, followed by essential post-treatments including drying, debinding, and sintering. The review further analyzes correlations between microstructure and functional performance, surveys key application domains spanning structural ceramics, biomedical scaffolds, and thermal materials, and concludes with current challenges and future outlook. Emerging trends highlighted include gradient structures, multi-material printing, machine-learning-guided process optimization, and one-step sintering approaches. DIW holds significant potential to advance the fabrication of high-performance ceramic components for aerospace, energy, electronics, and biomedical applications.