Fast Volumetric Fabrication: Breaking Through the 3D Barrier
While additive manufacturing (AM) and 3D printing technologies have proliferated and many have begun to mature, nearly all of them share the same fundamental limitation: the need to build via serially-iterated low-dimensional (voxel-by-voxel or layer-by-layer) fabrication steps. This paradigm implies slow fabrication speeds, and imposes some geometric limitations. The most notable of these are stair-step artifacts resulting in surface finish limitations for final parts, as well as challenges with producing cantilevered and spanning beam geometries (overhangs and bridges). A “true 3D” capability capable of volume-at-once fabrication of non-periodic 3D structures would be a highly desirable technological leap forward for the AM paradigm.
We have designed and built a prototype of such a system, working within the framework of photopolymer-resin-based fabrication. Our approach delivers designed non-periodic light intensity distributions into a resin volume, using holographic light shaping with a liquid-crystal-on-silicon spatial light modulator (SLM). By controlling exposure parameters to deliver sufficient energy to cure only pre-designed regions of the resin, the system allows mm-scale structures to be fabricated in seconds “all at once” from common photopolymers. We will report some details of system design, relevant optical and chemical parameters for producing high-quality 3D structures, and discuss some key parameter relationships and trade-offs.
Maxim Shusteff is a Staff Engineer and Principal Investigator at Lawrence Livremore National Laboratory, affiliated with the Center for Engineered Materials and Manufacturing, the Center for Micro-, Meso- and Nanotechnologies, and the Center for Bioengineering. In this role he has led a variety of R&D efforts in developing additive manufacturing technologies, with a particular emphasis on optically-driven 3D fabrication and micro-assembly. His second major area of research interest is in bioinstrumentation and microfluidic systems, with applications ranging from biological sample processing, preparation and analysis, to microfluidic platform development, and microelectrodes for neural interfacing. He holds a BSE degree from Princeton University and an MS degree from MIT, both in Electrical Engineering.