Custom mechanisms for tunable material deposition

Abstract

Digital fabrication tools, specifically additive manufacturing systems, have consistently advanced in efficiencies such as print speed, gantry size, material cost and ease of use. However most of these systems remain limited in their ability to enable automated mixing and extrusion of multiple materials with variable properties on large scales. This thesis focuses on the first steps of realizing this enabling technology by operating across two distinct trajectories. The first aims at digitally controlling precision path placement of material with high levels of tunability through analog mixing, while the second explores do-it-yourself tool customization, compactness, portability and the possibility of fabrication node-to-node communication. Inspired by the silkworm's ability to spin highly sophisticated and tunable material architectures, the aim of this thesis is to develop an enabling technology for digital fabrication requiring high levels of material tunability in product and architectural scales. Specifically, I designed, developed, built and evaluated an array of six unique customizable and compact deposition heads for tunable material properties. Amongst those tools is a freeform extrusion head for tunable geometry without the need for auxiliary support structure; a fast thread deposition head and a fiber winding head for tunable compressive and tensile strength respectively; a portable cable-suspended paste droplet extrusion head for tunable drop size of paste material; and a chitosan gel extrusion head for tunable plasticity using biomaterials. Operating across the two trajectories of tunability and portability, this thesis argues that highly tunable, compact and portable extrusion heads developed within a Fab Lab environment can support variable property printing of one or more materials outside of commercial based systems. This capability will in the future enable the digital fabrication of larger-scale prototypes, sustainable products and architectural structures inspired by nature in Fab Lab settings.