Opportunities at the frontier of multimaterial additive manufacturing with subvoxel control

Additive manufacturing (AM) has transformed materials production, enabling fabrication of components with complex geometries over a wide range of length scales. Multimaterial AM further enhances these capabilities by incorporating multiple materials into a single three-dimensional printed part. Direct ink writing, an extrusion-based AM method, is uniquely suited to printing a broad range of materials in filamentary form factors with programmable internal features. Programming of features smaller than the extruded filament diameter can be referred to as “subvoxel control,” where a “voxel” represents a volume element along the filament’s major axis. Subvoxel control offers new avenues for scalably generating hierarchically architected materials with enhanced functionality and performance. This article highlights emerging concepts in subvoxel control and recent advances in three subcategories: molecular structure, filler microstructure, and multimaterial architecture. The article closes with a discussion on future directions and contextualization within the broader landscape of recent advances in transformative manufacturing.