Soft pneumatic actuators produce more energy output per unit mass than conventional rigid pneumatic actuators and are safer for applications involving physical contact with users or fragile objects. The design, modelling, fabrication, and optimization of origami-inspired soft pneumatic actuators (OSPA) are investigated in this thesis. A novel fabrication method employing heat shrinkable polymers conforming to reusable 3D printed molds is proposed. It is rapid, cost-effective, and more systematic than prior OSPA fabrication methods. A nonlinear finite-element analysis (FEA) model for an OSPA based on the accordion crease pattern is developed for predicting the actuator's folding behavior and blocked force. The model includes a nonlinear hyperelastic model of the heat shrink material’s behaviour (obtained empirically) and nonlinear frictional contacts. It is validated with experimental results and is shown to predict the blocked force with a 5.7% maximum error. Prototypes of two OSPA designs (accordion and Yoshimura patterns) are fabricated. Isometric, isobaric, isotonic, and cyclic fatigue tests are performed on the accordion pattern OSPA. The tests demonstrate that it can lift more than 124 times its own weight, and had no decrease in performance after 150,000 contraction/extension cycles with a payload of 2 kg. This durability is superior to existing OSPA. Lastly, a FEA model-based design optimization approach is proposed. A multi-objective genetic algorithm (MOGA) is used to find the origami design parameters that maximize the accordion pattern OSPA's work output. The optimized design is validated experimentally. Although this research focuses on the accordion pattern OSPA, the proposed fabrication, modelling and optimization approaches can be easily adapted to other OSPA designs. In addition to linear force and motion, these actuators can be combined to produce different motions, e.g., a pair of actuators can be connected by a cable to a pulley in an agonist-antagonist arrangement to produce a bidirectional rotary actuator. / Thesis / Doctor of Philosophy (PhD) / Soft pneumatic actuators are lighter than conventional rigid pneumatic actuators and are safer for applications involving physical contact with users or fragile objects. The design, modelling, fabrication, and optimization of origami-inspired soft pneumatic actuators (OSPA) are investigated. A novel fabrication method that is rapid, cost-effective, and more systematic than prior OSPA fabrication methods is proposed. A nonlinear model is developed and shown to predict the OSPA’s output force with a 5.7% maximum error. An extensive series of tests are performed on OSPA prototypes. The accordion pattern OSPA can lift more than 124 times its own weight, and had no decrease in performance after 150,000 contraction/extension cycles with a payload of 2 kg. This durability is superior to existing OSPA. Lastly, a model-based approach for optimizing the OSPA design is presented and validated experimentally. The proposed fabrication, modelling and optimization approaches can be easily adapted to other OSPA designs.

Submitted by Samanta Aline Teixeira null (laranjasat@gmail.com) on 2017-03-30T11:46:07Z No. of bitstreams: 1 Dissertação Design do Origami.pdf: 20794490 bytes, checksum: 9b24019a67986dcaaa22f60facdf2b60 (MD5) / Rejected by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A versão final da dissertação/tese deve ser submetida no formato PDF (Portable Document Format) e o arquivo não deve estar protegido. Por favor, corrija o arquivo PDF e realize uma nova submissão com o arquivo desprotegido. Agradecemos a compreensão. on 2017-04-07T18:11:01Z (GMT) / Submitted by Samanta Aline Teixeira null (laranjasat@gmail.com) on 2017-04-08T19:17:31Z No. of bitstreams: 1 Dissertação digital DESIGN DO ORIGAMI.pdf: 9074846 bytes, checksum: ef1639468e0bb5a7a46290d0b5875d6e (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-11T18:31:46Z (GMT) No. of bitstreams: 1 teixeira_sa_me_bauru.pdf: 9074846 bytes, checksum: ef1639468e0bb5a7a46290d0b5875d6e (MD5) / Made available in DSpace on 2017-04-11T18:31:46Z (GMT). No. of bitstreams: 1 teixeira_sa_me_bauru.pdf: 9074846 bytes, checksum: ef1639468e0bb5a7a46290d0b5875d6e (MD5) Previous issue date: 2017-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A presente pesquisa busca investigar o papel científico e projetual que o origami, arte de dobrar papel, está desempenhando globalmente e como o design de dobras pode contribuir para o processo criativo e às inovações tecnológicas. Para tal, são consideradas três principais vertentes: 1) investigar o estado da arte do origami, desde o seu surgimento histórico até a evolução cronológica de pesquisa científica, processos de comunicação e segmentos estéticos; 2) analisar diferentes publicações do design do origami, as técnicas envolvidas e áreas de atuação; 3) desenvolver estudos de caso em prototipagem baseados no material estudado. Através do método indutivo-confirmável, o estudo possui dois momentos: pesquisa teórica bibliográfica e pesquisa prática experimental. O estudo teórico baseia-se na leitura e seleção de artigos de periódicos, publicações de congressos e livros que elucidem as diferentes possibilidades de ação projetual das dobraduras como a técnica do crease pattern e as vertentes do design de origami adaptado. O estudo experimental trata-se da construção de protótipos para a comprovação prática das técnicas e segmentos estudados. O objetivo de pesquisa está na compreensão da importância do design de origami em diferentes áreas do conhecimento teórico e aplicado e como as dobraduras são reapropriadas para gerar novas formas de construção e modelagem com os materiais e estruturas. Busca-se uma contribuição geral no sentido de solidificar mais e melhor os conceitos e pesquisas com o design do origami no Brasil. / The present research aims to investigate the projetual and scientific role that origami, folding paper art, is performing globally and how folds design can contribute to the creative process and to technological innovations. To this end, three main aspects are considered: 1) to investigate the state of origami’s art, from its historical emergence to the chronological evolution of scientific research, communication processes and aesthetic segments; 2) analyze different publications of origami design, the techniques involved and acting areas; 3) to develop case studies with prototyping based on the material studied. Through the inductive-confirmatory method, this study has two moments: theoretical bibliographic research and practical experimental research. The theoretical study is based on reading and selection of articles from journals, congress publications and books that elucidate the different possibilities of folds design as crease pattern technique and origami-adapted design. The experimental study is based on prototypes construction for practical verification of techniques and segments studied. The research objective is to understand the importance of origami design in different areas of theoretical and applied knowledge, and how foldings are reappropriated to generate new forms of construction and modeling with materials and structures. A general contribution is considered to solidify more and better the concepts and researches with origami design in Brazil.

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There are times when it is desirable for devices to be stowed compactly, ``transported'' to the location of their desired use, and then deployed to another stable shape or configuration to perform their designed function. Origami-based mechanisms are beneficial in these cases due to their compact, folded nature and large deployments. Unlike traditional mechanical design, compliant mechanism and origami-based design approaches inherently have coupled characteristics, creating complex design problems. The research presented here discusses metrics, methods, and designs to aid in the design of origami-adapted and compliant mechanisms, focusing on the design case of deployable space systems. First, the hexagonal twist origami pattern is used to develop performance metrics for next-generation deployable space arrays. These are shown using five different thickness accommodation techniques. The concepts are demonstrated through two applications: a deployable reflectarray antenna and a LiDAR telescope. Second, a highly compact stowable deployment is presented with the Deployable Euler Spiral Connectors (DESCs). These are compliant deployable flexures that can span gaps between segments in a mechanism and then lay flat when under strain in a stowed position. Additionally, a metamaterial is shown based on the combination of Euler spiral flexures (ESFs) to provide unique behaviors difficult to obtain in traditional materials, such as high compactability, decoupled motion and stiffness, tailorable Poisson's ratio, and multi-directional deployment. Third, this work presents a method for creating hinge-like motion for origami-adapted mechanisms using internal membranes attached between rigid panels. The goal is to remove adhesive requirements, preserve panel volume for use as hard stops, and reduce parasitic motion experienced by other membrane joint types, while keeping the stress in the membrane below the stress limits. Lastly, specific applications and examples of each of the above are shown throughout the work with a specific chapter highlighting more concise examples of creating metrics to determine the best origami patterns and to create compatible hinges. The presented techniques stand to greatly benefit the origami-adapted mechanisms design community.

Un origami, ou encore une surface à petits carreaux, est l'exemple le plus simple d'une surface de translation. Il s'obtient en collant entre eux un nombre fini de carreaux identiques. Le point le plus intéressant est l'étude du flot linéaire sur un origami, qui est un système dynamique continu lié à la dynamique des billards ou encore celle des échanges d'intervalles. Nous pouvons aussi nous intéresser au stabilisateur de l'action naturelle du groupe spécial linéaire sur les origamis, que nous appelons groupe de Veech de l'origami. Le but de cette thèse est l'étude de ces deux notions sur des exemples d'origamis infinis, obtenus en collant une infinité dénombrable de carreaux entre eux. Ces exemples sont obtenus comme revêtement galoisiens d'origamis finis, avec comme groupe de Galois des groupes abéliens, nilpotents ou plus compliqués. / An origami, or a square-tiled surface, is the simplest example of translation surface. An origami can be viewed as a finite collection of identical squares, glued together along their edges. We can study the linear flow on this origami, which is the geodesic flow for this kind of surfaces. This dynamical system is related to the dynamical system of billiard, or interval exchange transformations. We can also study the Veech group of an origami. The special linear group acts on the space of translation surface, and the Veech group of an origami is the stabilizer of this origami under this action. We know in particular that the Veech group is a fuchsian group. In this thesis, we work on some example of infinite origamis. These origamis are constructed as Galois covering of finite origamis. In these examples, the deck group will be an abelian group, a niltpotent group or something more difficult.

This thesis considered three types of new and improved high-performance energy absorbing devices for either compression or bending applications. These improvements were achieved by only altering their initial geometries for desired failure modes.

The cytoskeletal molecular motors kinesin-1 and cytoplasmic dynein drive many diverse functions within eukaryotic cells. They are responsible for numerous spatially and temporally dependent intracellular processes crucial for cellular activity, including cytokinesis, maintenance of sub-cellular organization and the transport of myriad cargos along microtubule tracks. Cytoplasmic dynein and kinesin-1 are processive, but opposite polarity, homodimeric motors; they each can take hundreds of thousands of consecutive steps, but do so in opposite directions along their microtubule tracks. These steps are fueled by the binding and hydrolysis of ATP within the homodimer's two identical protomers. Individual motors achieve their processivity by maintaining asynchrony between the stepping cycles of each protomer, insuring that at least one protomer always maintains contact with the track. How dynein coordinates the asynchronous stepping activity of its protomers is unknown. We developed a versatile method for assembling Saccharomyces cerevisiae dynein heterodimers, using complementary DNA oligonucleotides covalently linked to dynein monomers labeled with different organic fluorophores. Using two-color, single-molecule microscopy and high-precision, two-dimensional tracking, we found that dynein has a highly variable stepping pattern that is distinct from all other processive cytoskeletal motors, which use "hand-over-hand" mechanisms. Uniquely, dynein stepping is stochastic when its two motor domains are close together. However, coordination emerges as the distance between motor domains increases, implying that a tension-based mechanism governs these steps. Many cellular cargos demonstrate bidirectional movement due to the presence of ensembles of both cytoplasmic dynein and kinesin-1. To investigate the mechanisms that coordinate the interactions between motors within an ensemble, we constructed programmable synthetic cargos using three-dimensional DNA origami. This system enables varying numbers of DNA oligonucleotide-linked motors to be attached to the synthetic cargo, allowing for control of motor type, number, spacing, and orientation in vitro. In ensembles of one to seven identical- polarity motors, we found that motor number had minimal effect on directional velocity, whereas ensembles of opposite-polarity motors engaged in a tug-of-war resolvable by disengaging one motor species.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Matemática, 2014. / Submitted by Ana Cristina Barbosa da Silva (annabds@hotmail.com) on 2014-11-14T11:41:14Z No. of bitstreams: 1 2014_MarcondesSaboiaSilva.pdf: 1323450 bytes, checksum: 0baf9c652b3eaff3aa29de1ce6dfbb7c (MD5) / Approved for entry into archive by Patrícia Nunes da Silva(patricia@bce.unb.br) on 2014-11-17T11:19:43Z (GMT) No. of bitstreams: 1 2014_MarcondesSaboiaSilva.pdf: 1323450 bytes, checksum: 0baf9c652b3eaff3aa29de1ce6dfbb7c (MD5) / Made available in DSpace on 2014-11-17T11:19:43Z (GMT). No. of bitstreams: 1 2014_MarcondesSaboiaSilva.pdf: 1323450 bytes, checksum: 0baf9c652b3eaff3aa29de1ce6dfbb7c (MD5) / O objetivo principal desse trabalho é analisar o quanto a técnica do Origami influencia no processo ensino-aprendizagem da Geometria Euclidiana no Ensino Fundamental, em particular no 9º ano. Para isso foram elaborados um questionário para professores e uma avaliação diagnóstica para os alunos do 9º ano com conceitos básicos de Geometria, referentes a séries anteriores. Foi feita uma experiência em sala de aula, na qual cinco turmas do 9º ano foram divididas em dois grupos. Um dos grupos estudou Geometria com o auxílio do Origami e o outro grupo teve o mesmo conteúdo, mas de forma tradicional. Depois houve uma análise e uma comparação de resultados entre os dois grupos. __________________________________________________________________________ ABSTRACT / The main objective of this paper is to analyze how the technique of origami influences on the teaching-learning process of Euclidean geometry in elementary school, particularly in the 9th grade. For this a questionnaire for teachers and a diagnostic assessment for students in 9th grade with basic concepts of geometry relating to previous series were produced. We made in the classroom, in which five groups of the 9th grade were divided into two groups was made. One of the groups studied geometry with the aid of Origami and the other group had the same content but in a traditional way. Then there was an analysis and comparison of results between the two groups.

Paper folding is an underappreciated method with a number of interesting applications in real life. From Japanese traditional origami we moved to today's use in space research or medicine, all thanks to the application of mathematical principles on it. The work explains the basic rules of paper geometry and its difference from Euclidean geometry. The problems of doubling the cube or trisection of the angle, which cannot be solved in Euclidean geometry, can be solved quite easily by translating the paper. The thesis contains ideas for mathematics teachers from elementary school to high school on how to use paper folding directly in mathematics teaching. Among the ideas we can find a simple verification of the Pythagorean theorem and the construction of conic sections. Physical handling of paper helps to consolidate the topic, develops spatial imagination and dexterity.

No description available.