Digital fabrication with natural composites

Abstract

The purpose of the research work, an overview thereof presented here, is to create a new digital manufacturing technology with an emphasis on its sustainability characteristics. We designed a family of natural composite materials comprised of exclusively renewable, widely available, biodegradable, and low-cost components. Their physical and mechanical properties closely resemble those of high-density synthetic foams and low-density natural timbers. They are produced without inclusion of petrochemical products or harmful solvents and adhesives, often associated with adverse human and environmental effects. We designed a material extrusion system based on additive manufacturing principles similar to the Fused Deposition Modeling and the Direct Ink Writing methods. The mechanical system used is comprised of a mobile industrial robotic unit, a viscous liquid transport, and dispensing sub-system and programmable control logic. We performed extensive modeling and testing of material properties with the objective of tightly integrating material behavior with manufacturing. We developed design software for direct transition from design to production, including support scaffold generation for accelerated curing by evaporation and predictive models for process parameter control. To address the challenge of scale, we approached the fabrication process from a hybrid perspective including additive, net-zero-change, and subtractive operations. Early proof-of-concept demonstrators offers encouraging results towards manufacturing with two of the most abundant and widely distributed natural materials on earth. We believe that, with persistent effort of controlling the innate variability of natural materials and tighter integration with contemporary fabrication methods through predictive computational modeling, this process has very strong potential for a significant impact on product design, general manufacturing, and the building construction industry.