Modular origami

Abstract: This paper presents an origami-inspired cable-driven continuum manipulator module that offers low-cost, low-volume deployment, light weight, and inherently safe human interaction and collaboration. Each module has a mass of around 110 g and integrates the actuation, sensing, and control sub-systems necessary for operation. The origami structure has 7.311 Nm/rad (0.128 Nm/degree) torsional stiffness while being capable of bending in two directions and changing arc-length down to a fully collapsed state. A maximum contraction of 35 mm and bending angle of 35.5 degrees were achieved with 45 mm arc length. The module is capable of passively supporting a 1-kg mass at its tip, or 4 additional serially connected modules, bending approximately 6 degrees in the worst case. We also show that we can actively compensate for external moments by pre-compressing or pre-bending the module. We utilize an inverse kinematic control scheme and use it for both open and closed loop control following a circular trajectory. Our results indicate that the module motion follows the desired trajectory with an RMS error of 0.681 mm in the horizontal (x-y) plane and 0.373 mm in the z-axis with closed-loop control. We also assembled two origami modules in series and drove them independently, demonstrating the proof-of-concept of a modular origami continuum manipulator.

Abstract: Modular origami is a type of origami where multiple pieces of paper are folded into modules, and these modules are then interlocked with each other forming an assembly. Some of them turn out to be capable of large scale shape transformation, making them ideal to create metamaterials with tuned mechanical properties. In this paper, we examine 2D modular origami assemblies using mathematical tiling and patterns and carry out mechanism analysis, which leads to the development of various patterns consisting of interconnected quadrilateral modules. Due to the existence of 4R linkages within the patterns, they become transformable, and can be compactly packaged. Moreover, by the introduction of paired modules, we are able to adjust the expansion ratio of the pattern. Moreover, we demonstrate that transformable patterns with higher mobility exist for other polygonal modules. Our findings provide more design flexibility to achieve truly programmable metamaterials.

Abstract: This paper presents a novel modeling and fabrication technique of semi-soft mechanisms inspired by the origami twisted tower. The twisted tower is a modular origami structure consisting of multiple octagon-shaped layers. This structure can generate linear contraction, extension, and bending. A special geometric construct of this design allows each layer to fully collapse by twisting π/4°. Inspired by this unique feature, the design was further diversified to use any regular polygon with m sides, where m ≥ 3 and resulting maximum twisting within a single layer is 2π/m. This design diversification broadens potential applications of this mechanism. Such complex origami designs, however, faces one fundamental problem, i.e. manufacturability. There is no current manufacturing technique available for automating complex sequences of paper folding and assembling. To address this challenge, the twisted tower design was converted into a 3D printable model. 2-layer towers based on a triangle, square, pentagon, hexagon, and octagon were printed using the PolyJet™ 3D printing technology. For the octagon-based design, an additional 10-layer tower was printed to demonstrate the range of motions preserved from the hand-folded origami tower.

Abstract: This book presents origami techniques, examples and projects to stimulate, entertain and delight. It provides detailed advice on choosing appropriate paper, paperfolding techniques and base folds, and advanced techniques such as wet folding. It contains over 80 origami projects to fold, including traditional designs, animals and flowers, toys, games, action models, party tricks, decorative pieces and modular origami. It includes a feature gallery of some of the most highly regarded contemporary origamists. It is fully illustrated, step-by-step, with over 1,500 colour photographs. This practical guide combines a fascinating history of origami, an inspirational gallery featuring the work of the world's top origamists, detailed descriptions of paper to use, and over 80 step-by-step projects to challenge and delight. There are traditional Japanese models, toys, games and action origami, animals and flowers, practical origami for the home, party tricks, decorative models and stunning modular pieces. Each section begins with a simple project and progresses to models that will test your skills and reward you with a sense of accomplishment. With inspirational photography of each model and origami pieces to suit every ability, this book will ensure that you never look at a piece of paper in quite the same way again.