A Low-Cost, Open-Source 3D Printer for Multimaterial and High-Throughput Direct Ink Writing of Soft and Living Materials.

Direct ink writing is a 3D printing method that is compatible with a wide range of structural, elastomeric, electronic, and living materials, and it continues to expand its uses into physics, engineering, and biology laboratories. However, the large footprint, closed hardware and software ecosystems, and expense of commercial systems often hamper widespread adoption. This work introduces a compact, low-cost, multimaterial, and high-throughput direct ink writing 3D printer platform with detailed assembly files and instructions provided freely online. In contrast to existing low-cost 3D printers and bioprinters, which typically modify off-the-shelf plastic 3D printers, this system is built from scratch, offering a lower cost and full customizability. Active mixing of cell-laden bioinks, high-throughput production of auxetic lattices using multimaterial multinozzle 3D (MM3D) printing methods, and a high-toughness, photocurable hydrogel for fabrication of heart valves are introduced. Finally, hardware for embedded multinozzle and 3D gradient nozzle printing is developed for producing high-throughput and graded 3D parts. This powerful, simple-to-build, and customizable printing platform can help stimulate a vibrant biomaker community of engineers, biologists, and educators.