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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Controlled Sideways Assemblies of Dynamic DNA Origami Nanodevices and Gold Nanoparticle - DNA Origami Composites

Huang, Kehao 28 October 2022 (has links)
No description available.
22

An Approach for Designing Origami-Adapted Products with Aerospace Mechanism Examples

Morgan, Jessica 01 September 2015 (has links)
The objective of this research is to develop a design process for origami-adapted products and demonstrate it using aerospace mechanism examples. Origami-adapted design is a type of origami-based design. Origami-based design ranges from abstract to concrete applications of origami to design and includes: origami-inspired design, origami-adapted design, and origami-applied design. Origami-adapted design adapts origami fold patterns into products while preserving functionality. Some of the desirable attributes of origami that are sought after in design include: 1) reduced number of parts, 2) stowability, 3) deployability, 4) transportability, 5) manufacturability from a flat sheet of material, 6) ease of miniaturization, 7) a single manufacturing technique (folding) and 8) low material volume and mass. The proposed origami-adapted design process has four steps: define the problem, identify an origami solution, modify the fold pattern, and integrate. Intermediate steps apply tools to analyze and modify the origami fold pattern according to the design requirements. The first step defines whether origami is a viable solution by evaluating a set of starting criteria. Once it has been determined that origami is a viable solution, the design process guides the designer through a series of steps that modify the origami crease pattern until the final design is reached. The origami-adapted design process is applied to the design of three aerospace mechanism examples: an origami bellows, an expandable habitat, and a deployable parabolic antenna. The design process is followed throughout the design of these aerospace mechanisms. The origami bellows is designed and tested as a highly compressible origami bellows for harsh environments. It can be designed to endure 100,000+ cycles in fatigue and underwent testing for thermal cycling, abrasion, and radiation. The second example is a proof-of-concept expandable habitat for implementation as a module on the International Space Station. The design process aides in selecting an origami crease pattern and modifying it for thick, rigid materials. The last example is a deployable parabolic antenna. It is based on the flasher fold pattern with a wedge of the pattern removed to create curvature. It is experimentally verified to be approximately parabolic. The examples are shown to follow the origami-adapted design process and that the design process is flexible to accommodate a design's needs.
23

Methods for Creating Rigid Foldability in Origami-Inspired Deployable Mechanisms

Yellowhorse, Alden Daniel 01 July 2018 (has links)
Because origami has proved to be a tremendously rich source of inspiration in engineering, interest in solving some of the challenges that affect origami-inspired design has been significant. One such challenge involves ensuring that origami-inspired mechanisms are rigid-foldable or capable of moving without requiring links to bend or distort. Because rigid-foldability is essential in mechanisms that are constructed using rigid materials, access to methods of engineering this characteristic are highly desirable. This research addresses this need by developing methods for the design of origami-inspired mechanisms that are rigid-foldable. Methods for modifying crease patterns to achieve this are described and compared. Methods for achieving rigid-foldability using thick materials are also developed. Proofs of a process for generating new variations of existing thick-origami models are developed and demonstrated on multiple models. The possibility of using compliant panels to create rigid-foldability is also studied.Because of the relationship between mechanism stiffness and rigid-foldability, means of managing the pattern stiffness are also examined. The design of compliant, deployable stiffeners is studied to permit a comparison of different stiffener types. This comparison is used to identify dominant configurations that are most advantageous for a deployable mechanism. The use of thick-origami models are also considered. The geometry of two varieties of a cantilever tube are optimized to support a cantilever beam.
24

Kinematics of spatial linkages and its applications to rigid origami / La cinématique des mécanismes spatiaux et ses applications à l'origami rigide

Feng, Huijuan 30 May 2018 (has links)
La thèse conduit une analyse cinématique des mécanismes spatiaux allant de mécanismes sphériques aux mécanismes spatiaux sur-contraints basés sur la méthode matricielle D-H et l’applique pour explorer le comportement rigide de pliabilité et de mouvement des modèles d’origami. Dans ce processus, la pliabilité rigide du motif origami en torsion triangulaire est d’abord examinée sur la base de la cinématique du réseau de mécanismes 4 R sphériques et de nouveaux mécanismes 6 R sur-contraints dérivés par la technique du kirigami. Ensuite, la cinématique du mécanisme de Bricard 6 R plan-symétrique est analysée et ses variations de bifurcation sont discutées. Après cela, les résultats sont appliqués pour étudier le pliage symétrique de l’origami de la waterbomb à six plis à panneau épais, qui est modélisé sous laforme d’un réseau de mécanismes de Bricard 6 R plan-symétriques. Le comportement de mouvement de sa tessellation correspondante de feuille de zéro-épaisseur est démontré par unréseau de mécanismes 6 R sphériques. Enfin, le comportement de mouvement de la forme cylindrique fermée de l’origami de la waterbomb est analysé à travers une étude paramétrique, en le modélisant comme un réseau fermé de mécanismes 6 R sphériques. Ces études aident à approfondir la compréhension de la cinématique des mécanismes spatiaux et du mouvement rigide de l’origami, et à jeter les bases des applications techniques des mécanismes spatiaux et des motifs d’origami rigides. / This dissertation conducts kinematic analysis of spatial linkages ranging from spherical linkages to overconstrained linkages based on the D-H matrix method, and applies it to explore the rigid foldability and motion behaviour of origami patterns. In this process, the rigid foldability of triangle twist origami pattern is firstly examined based on the kinematics of spherical 4 R linkage network and new overconstrained 6 R linkages are derived by kirigami technique. Then the kinematics of the plane-symmetric Bricard 6 R linkage is analyzed and its bifurcation variations are discussed. After that, the results are applied to study the symmetric folding of six-crease thick-panel waterbomb origami, which is modelled as a network of planesymmetric Bricard 6 R linkages. The motion behaviour of its corresponding tessellation of zerothickness sheet is demonstrated by a network of spherical 6 R linkages. Finally, the motion behaviour of the closed cylindrical form of waterbomb origami is investigated through a parametric study, by means of modelling it as a closed network of spherical 6 R linkages. These studies help to deepen the understanding of spatial linkage kinematics and rigid origami motion, and lay the foundation for engineering applications of spatial linkages and rigid origami patterns.
25

A gênese do espaço projetivo e as interações socias nos jogos de regras e de construção

Farias, Stela Maris Vaucher January 2006 (has links)
Resumo não disponível.
26

Art to Engineering: Curved Folding and Developable Surfaces in Mechanism and Deployable Structure Design

Nelson, Todd G 01 June 2018 (has links)
This work investigates how curved-crease origami and the developable surfaces which compose it can be transitioned to engineering design. Methods for creating flexible, tailorable-property surfaces that function as thick panels in place of paper are presented. Concepts from curved-crease origami and developable surfaces that can describe and extend engineering applications are discussed and demonstrated. These concepts are particularly beneficial to applications where curved surfaces are integral to the function, deployability is desired, and planar manufacturing could be beneficial.The first part of this work uses arrays of compliant elements to create flexible-tailorable property surfaces. The key feature to these arrays is the alignment of the most flexible bending axis of the individual elements to the ruling line arrangement of a developable surface. This alignment can enable bending of thick panels while maintaining lower stresses, a quality necessary for the transitioning of curved-crease origami into thick materials. The stiffness and stress of these arrays is modeled and physical prototypes are demonstrated. Additionally, shape factors are developed for these compliant arrays (CAs) to facilitate material selection for the panels and understand how the geometry of the array changes the effective properties of the panel. The second part of this work describes and demonstrates several concepts of curved-crease origami and developable surfaces that can benefit mechanism and structure design, particularly in the context of rolling-contact mechanisms. The design of a rolling-contact joint connected by flexible bands similar to a Jacob's Ladder toy is extended through incorporating curved creases into the design. The resulting design is deployable from a compact state to a functional state and can be manufactured from a single plane and folded into shape. Mathematical formulations are presented to describe the classes of developable surfaces in terms of properties which are frequently important in mechanism design. These natural equations for a single class of developable surface are conducive to modeling the folding motion of rigid-ruling developables, developables whose ruling lines do change location in a surface during folding. These formulations are used to generalize the design of rolling-contact joints to a family of joints capable of single degree of freedom spatial motions, being manufactured from a plane, and exhibiting a tailorable force response. Finally practical design suggestions for the implementation of rolling-contact joints is given. These include methodology to create sunken flexures which serve to increase the normal force between rolling bodies to prevent slip.
27

Developing Hybrid Thickness-Accommodation Techniques for New Origami-Inspired Engineered Systems

Tolman, Kyler Austin 01 May 2017 (has links)
Origami has become a source of inspiration in a number of engineered systems. In most systems, non-paper materials where material thickness is non-negligible is required. In origami-inspired engineered systems where thickness is non-negligible, thickness-accommodation techniques must be utilized to overcome the issue of self-intersection. Many thickness-accommodation techniques have been developed for use in thick-origami-inspired-engineered systems. In this work several thickness-accommodation techniques are reviewed and discussed. New thickness-accommodation techniques including hybrid thickness-accommodation techniques and the split vertex technique are presented and discussed. These techniques enable new capabilities of thickness-accommodation in origami adapted design. Thickness-accommodation techniques have been developed in the context of developable origami patterns and the application of these techniques to non-developable patterns is introduced here. The capability of non-developable thick origami is demonstrated in an application example of a deployable locomotive nose-fairing.
28

DNA Origami Stabilized and Seeded with 4'-Aminomethyltrioxsalen for Improved DNA Nanowire Fabrication

McDowell, Matthew Paul 01 July 2015 (has links)
A fast emerging technology in the microelectronics field is bottom-up self-assembly of computer circuitry. A promising method to develop nanoelectronic devices through bottom-up self-assembly is the implementation of DNA-based technologies. Using DNA to create nanoelectronic devices is advantageous because of its already well understood base-paring and annealing qualities. These base-pairing and annealing qualities can be used to design and construct DNA nanostructures called DNA origami. DNA origami are specially designed structures made from single stranded DNA. Short single stranded DNA oligonucleotides called staple strands attach to a large single stranded DNA called a DNA scaffold. DNA staple strands and DNA scaffold anneal to each other and fold into DNA origami. Constructing DNA origami is advantageous because structures can be made in a single folding step. In particular, bar-shaped DNA origami has proven to be a promising structure for nanoelectronics fabrication. Here, I present new research done to improve bar-shaped DNA origami design and fabrication for constructing bottom-up self-assembled templates for nanomaterial surface attachment. Furthermore, this work presents new methods for DNA origami agarose gel purification with the help of the DNA stabilizing molecule, 4'-aminomethyltrioxsalen (AMT). AMT is a photoreactive molecule that intercalates DNA and creates covalent crosslinks when irradiated by short wavelength ultraviolet light. Also, this work contains new research on a synthesized crosslinker and its role with AMT in nanoparticle surface seeding on DNA origami nanowire templates. Through its crosslinking properties, AMT serves as a DNA origami stabilizing molecule and also shows potential for seeding nanomaterials.
29

Developing New Classes of Thick-Origami-Based Mechanisms: Conceal-and-Reveal Motion and Folding Printed Circuit Boards

De Figueiredo, Bryce Parker 01 November 2017 (has links)
Origami-adapted mechanisms form the basis of an increasing number of engineered systems. As most of these systems require the use of non-paper materials, various methods for accommodating thickness have been developed. These methods have opened new avenues for origami-based design. This work introduces approaches for the design of two new classes of thick-origami systems and demonstrates the approaches in hardware. One type of system, called "conceal-and-reveal,'' is introduced, and a method of designing these mechanisms is developed. Techniques are also developed for designing folding printed circuit boards which are fabricated from a single sheet of material. This enables areas of regional flexibility, leaving other areas stiff. This allows components to be attached to stiff regions and folding to occur at flexible regions. An optimization method is presented to design the geometry of surrogate hinges to aid in monolithic origami-based mechanisms such as flexible PCBs. Examples are shown which demonstrate each of these new techniques.
30

Strukturer : Experiment med hantverkstekniker

Andersson, Mari, Rovin, Elin January 2012 (has links)
I vårt examensarbete har vi experimenterat medtraditionella hantverkstekniker i syfte att hitta nya sättatt använda oss av dem i inredningar och på möbler.Som tapetserare var vi intresserade av att utgå ifråndessa tekniker för att upptäcka nya sätt att skapaspännande strukturer i klädselarbetet på möbler. I den inledande delen går vi in på de frågor vi villundersöka samt vad som är målet med vårt arbete.Därefter följer huvuddelen där de praktiska testernaredovisas. Här har vi praktiskt testat och arbetatutifrån ett stort antal tekniker för att se vilka som harpotential att användas för vårt syfte. Dessa har tillstörsta delen varit väl beprövade hantverksteknikersom vi har försökt förnya till exempel genom attanvända oss av andra material än vad som vanligtvisanvänds, ändra dimension eller enbart genom attsätta in tekniken i ett nytt sammanhang. I denavslutande delen beskriver vi utvecklingen ochresultatet av ett fåtal tekniker som vi arbetat vidaremed. Vi avslutar med en sammanfattning och enreflekterande diskussion. Det har varit en otroligt spännande och kreativprocess som har utmynnat i många intressanta idéeroch objekt.

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