Multimaterial Actinic Spatial Control (MASC) 3D Printing

Creation of multimaterial parts with complete 3-dimensional geometric freedom is a considerable challenge with potentially game-changing potential for manufacturing capabilities. Various approaches within the additive manufacturing and 3D printing communities have relied on equipment modifications that enable segregation of build materials and then selective deposition of different materials (from separate reservoirs) during printing. We propose a chemical approach to multimaterial parts fabrication that allows for a breadth of compositional diversity through orthogonal reaction mechanisms that can be mediated by different wavelengths of light. In this way, we are able to create multimaterial parts from single resin reservoirs (or vats) and control compositional gradients, heterogeneity, feature sizes, and colour without requiring complex compatibilization of vastly disparate build materials. Our published results already confirmed the ability to create soft-stiff materials combinations from a mixture of acrylate- and epoxide-based monomers. Our unpublished preliminary results have now confirmed the ability to create metallic components in the final parts, using photoredox catalysed reduction of soluble metal salts. Additionally, we have introduced some exciting resin features such as the ability to permanently alter colour through modulation of local pH via application of light, and a class of acrylate resin that produces soluble thermoplastics after photocuring. Specific targets of our program thus include: 1) creation of composite structures and open cell foams entirely via liquid-to-solid photocuring (no solids required in the resin feed), 2) creation of organic-inorganic combinations in multimaterial parts (e.g., circuitry, flexible electronics, antennae metamaterials), and 3) access to multicolor materials including custom camouflage patterns throughout a 3D part from a single resin composition.