Hideo Nakajima
Porous metallic materials such as foamed metals, sponge-like metals, structural cellular metals, metals with directional pores and sintered metals are increasingly looked upon as potential light-weight structural and functional materials with, for example, superior sound absorption, damping and filtering properties. Not only porous metals but also porous ceramics, semiconducting materials and polymers are attracted much attention as unique functional materials in various fields, and some of them have been already implemented.