3D microprinting of inorganic porous materials by chemical linking-induced solidification of nanocrystals

Abstract Three-dimensional (3D) microprinting is considered a next-generation manufacturing process for the production of microscale components; however, the narrow range of suitable materials, which include mainly polymers, is a critical issue that limits the application of this process to functional inorganic materials. Herein, we develop a generalised microscale 3D printing method for the production of purely inorganic nanocrystal-based porous materials. Our process was designed to solidify all-inorganic nanocrystals via immediate dispersibility control and surface linking in the nonsolvent linker bath and thereby created multibranched gel networks. The process works with various inorganic materials, including metals, semiconductors, magnets, oxides, and multi-materials, not requiring organic binders or stereolithographic equipment. Filaments with a diameter of sub-10 µm are printed into designed complex 3D microarchitectures, which exhibit full nanocrystal functionality and high specific surface areas comparable to those of typical aerogels. This approach enables the manufacture of a very broad range of functional inorganic materials.