Design and analysis of digital materials for physical 3D voxel printing

Purpose – Virtual voxels (3D pixels) have traditionally been used as a graphical data structure for representing 3D geometry. The purpose of this paper is to study the use of pre-existing physical voxels as a material building-block for layered manufacturing and present the theoretical underpinnings for a fundamentally new massively parallel additive fabrication process in which 3D matter is digital. The paper also seeks to explore the unique possibilities enabled by this paradigm. Design/methodology/approach – Digital RP is a process whereby a physical 3D object is made of many digital units (voxels) arranged selectively in a 3D lattice, as opposed to analog (continuous) material commonly used in conventional rapid prototyping. The paper draws from fundamentals of 3D space-filling shapes, large-scale numerical simulation, and a survey of modern technology to reach conclusions on the feasibility of a fabricator for digital matter. Findings – Design criteria and appropriate 3D voxel geometries are presented that self-align and are suitable for rapid parallel assembly and economical manufacturing. Theory and numerical simulation predict dimensional accuracy to scale favorably as the number of voxels increases. Current technology will enable rapid parallel assembly of billions of microscale voxels. Research limitations/implications – Many novel voxel functions could be realized in the electromechanical and microfluidic domains, enabling inexpensive prototyping of complex 3D integrated systems. The paper demonstrates the feasibility of a 3D digital fabricator, but an instantiation is out of scope and left to future work. Practical implications – Digital manufacturing offers the possibility of desktop fabrication of perfectly repeatable, precise, multi-material objects with microscale accuracy. Originality/value – The paper constitutes a comprehensive review of physical voxel-based manufacturing and presents the groundwork for an emerging new field of additive manufacturing.