Book excerpt: Metamaterial Design and Additive Manufacturing covers optimization design, manufacturing, microstructure, mechanical properties, acoustic properties, mass-transport properties and application examples of PMs fabricated by selective laser melting additive manufacturing technology. The book introduces the definition and concept of pentamode metamaterials and then describes their characterization, including manufacturing fidelity, mechanical response, acoustic properties and so on. Final sections analyze research situations, problems and applications of additive manufacturing pentamode metamaterials. - Covers design and optimization methods of pentamode metamaterials - Describes manufacturing fidelity, microstructure and physical properties of pentamode metamaterials fabricated by AM - Includes recent applications for pentamode metamaterials, along with research situations and potential problems