Multi-material additive manufacture and microwave-assisted sintering of a metal/ceramic metamaterial antenna structure

•Metal/Ceramic structures have been prepared by combining multi-material extrusion 3D printing and microwave-assisted sintering.•Sintering Ag2MoO4 at 480 °C for 2 h resulted εr = 10.99 ± 0.04 and q × f = 2597 ± 540 GHz.•Microwave-assisted sintering was used to densify ag electrodes within a multi-layered metal/ceramic structure.•A functional metal/ceramic metamaterial antenna structure was fabricated. Multi-material metal/ceramic 3D structures comprising of metallic silver and ultra-low sintering temperature silver molybdenum oxide ceramics, have been additively manufactured and hybrid densified using microwave-assisted sintering for the first time. Optimum densification conditions at 440 °C / 1 h, resulted in relative permittivity, εr = 10.99 ± 0.04, dielectric losses, tanδ = 0.005 ± 0.001 and microwave quality factor, Q × f = 2597 ± 540 GHz. Applying 2 kW microwave energy at 2.45 GHz for 60 min, was proven sufficient, to densify the metallic Ag infilling electrodes, without causing any macroscopic defects. A fully functional multi-layered antenna structure with a metamaterial artificial magnetic conductor was designed, dual-printed and densified, to showcase the potential of combining multi-material additive manufacturing with microwave-assisted sintering. [Display omitted]