Enabling new functionally embedded mechanical systems via cutting, folding, and 3D printing

Wei Gao, Purdue University

Abstract

Traditional design tools and fabrication methods implicitly prevent mechanical engineers from encapsulating full functionalities such as mobility, transformation, sensing and actuation in the early design concept prototyping stage. Therefore, designers are forced to design, fabricate and assemble individual parts similar to conventional manufacturing, and iteratively create additional functionalities. This results in relatively high design iteration times and complex assembly strategies. Stemmed from an ancient paper craft originating from Japan, Origami has been naturally contextualized in a variety of applications in the fields of mathematics, engineering, food packaging, and biological design. The computational and manufacturing capabilities today urge us to develop significantly new forms and processes of folding to create functional enclosures", where full functionalities can be easily pre-synthesized and pre-embedded on flat. Furthermore, The external skin shapes are allowed to be "coated" over enclosures using 3D printing process. In the first phase of this thesis, by introducing line cuts into crease patterns and creating folded hinges across ''Basic Structural Units" (BSUs), typically not done in origami, we achieve a new multi-primitive folding framework using tetrahedral, cuboidal, prismatic, and pyramidal components, called "Kinetogami". The mathematical and folding theories are established to construct closed-loop(s) polyhedral mechanisms with multi-degree-of-freedom and self-deployable characteristics using a single sheet of material. The explicit 2D fabrication layout and construction rules are visually parameterized for geometric properties to ensure a continuous and intersection-free folding motion. Next, the study presents the prototypical results from a variety of foldable polyhedral mechanisms to the locomotive hexapod robots, using the tetrahedral module derived from Kinetogami. We also investigate the kinematic interpretation of reconfiguration between the folds and material selection of substrates and hinges. The last phase of this thesis focuses on combining functionally-embedded design along with the shape creation by embedding components during 3D printing. By modifying a standard low-cost FDM printer with a revolving and foldable cuboidal platform, and printing partitioned geometries around cuboidal facets, we achieve a multi-directional additive prototyping process, called "RevoMaker". A wide range of customized and fully-functional product prototypes, such as computer mice and wind-up toys are demonstrated in our prototyping results. Therefore, via integrating dimensions of folding, cutting and 3D printing, we achieve a shape-to-form-to-function design and prototyping framework that provides affordance for a new genre of functionally-embedded mechanical products and systems.

Degree

Ph.D.

Advisors

Cipra, Purdue University.

Subject Area

Mechanical engineering

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