Treating bone defects is highly challenging because they do not heal on their own inside the patients, so implants are needed to assist in the reconstruction of the bone. Bioceramic implants based on additive manufacturing (AM) are currently emerging as promising treatment options for restoration bone engineering. On the one hand, additively manufactured bioceramic implants have excellent mechanical properties and biocompatibility, which are suitable for bone regeneration. On the other hand, the designable structure and adjustable pores of additively manufactured bioceramic implants allow them to promote suitable cell growth and tissue climbing. Herein, this review unfolds to introduce several frequently employed AM technologies for bioceramic implants. After that, advances in commonly used additively manufactured bioceramic implants, including bioinert ceramic implants, bioactive ceramic implants, and bioceramic/organic composite implants, are categorized and summarized. Finally, the future perspectives of additively manufactured bioceramic implants, in terms of mechanical performance improvement, innovative structural design, biological property enhancement, and other functionalization approaches, are proposed and forecasted. This review is believed to provide some fundamental understanding and cutting-edge knowledge for the additive manufacturing of bioceramic implants for restoration bone engineering.

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Direct-ink-writing (DIW)-based 3D-printing technology combined with the direct-foaming method provides a new strategy for the fabrication of porous materials. We herein report a novel method of preparing porous SiC ceramics using the DIW process and investigate their mechanical and wave absorption properties. We investigated the effects of nozzle diameter on the macroscopic shape and microstructure of the DIW SiC green bodies. Subsequently, the influences of the sintering temperature on the mechanical properties and electromagnetic (EM) wave absorption performance of the final porous SiC-sintered ceramics were also studied. The results showed that the nozzle diameter played an important role in maintaining the structure of the SiC green part. The printed products contained large amounts of closed pores with diameters of approximately 100–200 μm. As the sintering temperature increased, the porosity of porous SiC-sintered ceramics decreased while the compressive strength increased. The maximum open porosity and compressive strength were 65.4% and 7.9 MPa, respectively. The minimum reflection loss (RL) was −48.9 dB, and the maximum effective absorption bandwidth (EAB) value was 3.7 GHz. Notably, porous SiC ceramics after sintering at 1650 °C could meet the application requirements with a compressive strength of 7.9 MPa, a minimum RL of −27.1 dB, and an EAB value of 3.4 GHz. This study demonstrated the potential of direct foaming combined with DIW-based 3D printing to prepare porous SiC ceramics for high strength and excellent EM wave absorption applications.

Micro/nano‐scaled mechanical metamaterials have attracted extensive attention in various fields attributed to their superior properties benefiting from their rationally designed micro/nano‐structures. As one of the most advanced technologies in the 21st century, additive manufacturing (3D printing) opens an easier and faster path for fabricating micro/nano‐scaled mechanical metamaterials with complex structures. Here, the size effect of metamaterials at micro/nano scales is introduced first. Then, the additive manufacturing technologies to fabricate mechanical metamaterials at micro/nano scales are introduced. The latest research progress on micro/nano‐scaled mechanical metamaterials is also reviewed according to the type of materials. In addition, the structural and functional applications of micro/nano‐scaled mechanical metamaterials are further summarized. Finally, the challenges, including advanced 3D printing technologies, novel material development, and innovative structural design, for micro/nano‐scaled mechanical metamaterials are discussed, and future perspectives are provided. The review aims to provide insight into the research and development of 3D‐printed micro/nano‐scaled mechanical metamaterials.