This review by Sylvain Deville provides an overview of the current state and challenges in freeze-casting of porous ceramics. Freeze-casting involves the solidification of a solvent to create a porous structure, which has gained significant attention due to its ability to produce unique structures and properties. The process involves four main steps: slurry preparation, controlled solidification, sublimation of the solvent, and sintering. The choice of solvent, solidification conditions, and slurry formulation significantly influence the final structure and properties of the ceramic materials. Key findings include: - The porosity and morphology of the final product are highly dependent on the solvent used, with water producing lamellar structures, camphene leading to dendritic structures, and tert-butyl alcohol resulting in prismatic structures. - The directionality of the porosity can be controlled by the solidification conditions, allowing for unidirectional or complex orientations. - The compressive strength of freeze-cast porous ceramics can be significantly improved, particularly for materials like hydroxyapatite, which exhibit strength comparable to compact bone. - The process has potential applications in biomaterials, chemical processes, energy sources, and photocatalysis, where the unique structure and properties of the ceramics are advantageous. However, the review also highlights several limitations, such as the difficulty in controlling the solid content in the slurry, the challenges in achieving uniform porosity, and the need for further research to optimize the process for larger scales. Perspectives for future developments include improving the setup for better temperature control and directionality, as well as exploring functional structures through post-processing techniques.This review by Sylvain Deville provides an overview of the current state and challenges in freeze-casting of porous ceramics. Freeze-casting involves the solidification of a solvent to create a porous structure, which has gained significant attention due to its ability to produce unique structures and properties. The process involves four main steps: slurry preparation, controlled solidification, sublimation of the solvent, and sintering. The choice of solvent, solidification conditions, and slurry formulation significantly influence the final structure and properties of the ceramic materials. Key findings include: - The porosity and morphology of the final product are highly dependent on the solvent used, with water producing lamellar structures, camphene leading to dendritic structures, and tert-butyl alcohol resulting in prismatic structures. - The directionality of the porosity can be controlled by the solidification conditions, allowing for unidirectional or complex orientations. - The compressive strength of freeze-cast porous ceramics can be significantly improved, particularly for materials like hydroxyapatite, which exhibit strength comparable to compact bone. - The process has potential applications in biomaterials, chemical processes, energy sources, and photocatalysis, where the unique structure and properties of the ceramics are advantageous. However, the review also highlights several limitations, such as the difficulty in controlling the solid content in the slurry, the challenges in achieving uniform porosity, and the need for further research to optimize the process for larger scales. Perspectives for future developments include improving the setup for better temperature control and directionality, as well as exploring functional structures through post-processing techniques.