For porous ceramics, the microstructure is made up of small crystals called grains. In general, the smaller the grain size, the stronger and denser is the ceramic material.The wide variety of applications for porous ceramic materials results from their unique properties. In many respects, these properties cannot be achieved by other materials.

        The challenge now is for materials scientists to produce ceramics with porosity of any fraction, shape, and size. This also leads to new directions in the scientific understanding of porous structures field.