3D Printing of Ultra-Strong and Hierarchically Porous Nanoarchitectures Using Nanocluster-Based Photoresists

One longstanding challenge in 3D printing, or additive manufacturing, is the lack of feedstock solution to realize the complicated high-precision structures of inorganic and composite materials which are expected to show superior mechanical properties. Herein, we report a general photoresist strategy that enables the rapid sub-micron 3D printing of various inorganic-organic composite materials with arbitrarily complex architectures, controllable and hierarchical porosities, anisotropic alignments and tunable compositions, as well as the outstanding mechanical properties which fill the white space of Ashby charts and attain the theoretical strength of constituent materials. Different from traditional resins, our photoresists exploit the unique chemical and physical properties of ultrasmall metal nanoclusters which serve as highly sensitive two-photon initiators, metal sources, nano-porogens and strengthening fillers. Based on their superior printability, their ability to make previously inaccessible structures, and their capacity to improve the mechanical performance of structures out of conventional regimes, we envision that the nanocluster-photoresists may enable substantial advances in additive nanomanufacturing.