Robocasting of a Water‐Based Biopolymer/WO ₃ Nanopowder Paste as a Precursor to Tungsten Carbide Lattices

Tungsten carbide (WC) shows excellent potential as a structural electrode material for many applications, such as lightweight structural energy components and catalysts. This work focuses on validating direct ink writing/robocasting and heat treatment as a suitable method to manufacture complex shapes and components of porous WC and builds upon previous reports about the characterization of the ink used here. The technique presented utilizes a modified fused deposition modeling printer to extrude a biopolymer precursor paste containing tungsten oxide nanoparticles into lattice shapes. Of note, the printed material is water‐based and without any further additives. Heat treatment of the printed lattice structures in an inert atmosphere results in 3D cellular architectures of porous WC. The focus of this work is on characterizing the printing fidelity, reproducibility, and robustness of the process. To this end, the printing performance of the robocasting platform, including overhangs, and the shrinkage that occurs at different stages of the process are reported. Characterization results of the structures show a porous network of WC particle agglomerates, confirming previous results, while electrical characterization during compression testing shows a sustained electrical conductivity across the structure until the point of mechanical failure.