Water-based Engineering & Fabrication: Large-Scale Additive Manufacturing of Biomaterials

In nature, water assembles basic molecules into complex multi-functional structures with nano-to-macro property variation. Such processes generally consume low amounts of energy, produce little to no waste, and take advantage of ambient conditions. In contrast digital manufacturing platforms are generally characterized as uni-functional, wasteful, fuel-based and often toxic. In this paper we explore the role of water in biological construction and propose an enabling technology modeled after these findings. We present a water-based fabrication platform tailored for 3-D printing of water-based composites and regenerated biomaterials such as chitosan, cellulose or sodium alginate for the construction of highly sustainable products and building components. We demonstrate that water-based fabrication of biological materials can be used to tune mechanical, chemical and optical properties of aqueous material composites. The platform consists of a multi-nozzle extrusion system attached to a multi-axis robotic arm designed to additively fabricate extrusion-compatible gels with graded properties. Applications of the composites include small and medium-scale recyclable objects, as well as temporary largescale architectural structures.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract W911NF-13-D-0001