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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.
121

Origami e robótica : do plano ao tridimensional /

Moraes, Daniel Seda Pereira de. January 2018 (has links)
Orientador(a): Rosangela da Silva Leote / Banca: José Spaniol / Banca: Almir Almas / Resumo: Nesta dissertação, eu discuto algumas das relações entre arte, ciência e tecnologia a partir da conexão entre o papel e a eletrônica. O foco da dissertação é como o papel, tecnologia ancestral, pode ganhar outras aplicações, especialmente na arte, ao se conectar a sistemas de código aberto para robótica. O conhecimento teórico e experimental sobre o tema converte-se na produção de uma série de objetos cinéticos apresentados em uma exposição junto com o texto final desta dissertação, que contém também um tutorial abrindo o código das obras realizadas, permitindo a sua replicação por outras pessoas / Abstract: In this text, I discuss relations between art, science and technology starting from the connection between paper and electronics. The focus is how paper, ancestral technology, can gain other applications, especially in art, when connecting to open source systems for robotics. Theoretical and experimental knowledge on the subject compose a series of kinetic objects presented in an exposition along with the final text of this dissertation, which also contains a tutorial opening the code of the works carried out, allowing their replication by other people / Mestre
122

Inserção da técnica de origami no processo de projetação de embalagens

Blum, Arina 31 March 2010 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-04-01T16:47:41Z No. of bitstreams: 1 Arina Blum_.pdf: 6104334 bytes, checksum: 8c18d6b9bf68975576609eff819cffa3 (MD5) / Made available in DSpace on 2016-04-01T16:47:41Z (GMT). No. of bitstreams: 1 Arina Blum_.pdf: 6104334 bytes, checksum: 8c18d6b9bf68975576609eff819cffa3 (MD5) Previous issue date: 2010-03-31 / Nenhuma / O presente trabalho apresenta a pesquisa que teve por objetivo avaliar a influência da inserção da técnica de origami no processo de projetação de embalagens. O estudo baseou-se na análise das características do origami e de sua analogia estética com determinados formatos de embalagens e, ainda, na descrição e confrontação de onze diferentes métodos projetuais. A investigação delineou-se por uma pesquisa qualitativa de natureza experimental, onde quatro grupos – compostos cada um por três profissionais atuantes na área do design – foram instigados, num ambiente de workshop, à resolução de um mesmo briefing para desenvolvimento projetual de uma embalagem. Dois destes grupos foram observados como caráter de controle e os outros dois receberam o tratamento experimental através de uma oficina de origami. Os resultados apontam para o mapeamento do processo de projeto utilizado nos workshops e sua relação com a solução projetual apresentada e o uso do origami no processo. O estudo destaca a confirmação de que o conhecimento da técnica de dobradura de papel pode gerar alternativas influenciadoras no processo de projeto de embalagens e, em contrapartida, abre indicativos para continuação desta pesquisa. / This paper presents the research that had as a goal to evaluate the influence of the inclusion of the origami technique at the package design process. The research is based on the analysis of origami's characteristics and his aesthetic analogy with certain forms of packages and, also, on the description and confrontation of eleven different projecting methods. The investigation was outlined by a qualitative study of an experimental nature, on which, four groups - each one composed by three professionals working in the design area - were instigated, at a workshop environment, to appoint a solution to the same briefing document for a projectual development of a package. Two of these groups were observed for control and the other two received the experimental treatment trough a origami workshop. The results point to the mapping of the design process used in workshops and their relationship with the given projectual solution and the use of origami in the process. The study highlights the confirmation that the knowledge of the paper folding technique may create influent alternatives in the package design process and therefore opens indicative to the continuation of this research.
123

DNA nanotechnology and nanopatterning : biochips for single-molecule investigations

Huang, Da January 2017 (has links)
The controlled organization of individual molecules and nanostructures with nanoscale accuracy is of great importance in the investigation of single-molecule events in biological and chemical assays, as well as for the fabrication of the next generation optoelectronic devices. In this regard, the precise patterning of individual molecules into hierarchical structures has attracted substantial research interest in recent years. DNA has been shown to be an ideal structural material for this purpose, due to the specificity of its programmability and outstanding chemical flexibility. DNA origami can display a high degree of positional and precise binding sites, allowing for complex arrangements and the assembly of different nanoscale architectures. In this project, we present a novel platform based on the use of DNA scaffolds for the organization of individual nanomoieties (with nanoscale spatial control), and their selective immobilisation on surfaces for single-molecule investigations. In particular, semiconductor quantum dots (QDs), fluorescence molecules, linear small peptides, and structural proteins were tethered with single-molecule accuracy on DNA origami; their subsequent organization in array configuration on nanopatterned surfaces allowed us to fabricate and test different platforms for single-molecule studies. In particular, we developed a Focused Ion Beam (FIB) nanofabrication strategy and demonstrated its general applicability for the assembly of functionalised DNA nanostructures in highly uniform nanoarrays, with single-molecule control. In addition, we further explored this nanofabricated platform for biological investigations at the single-molecule level, from protein-DNA interactions to cancer cell adhesion studies with single-molecule control. Investigations have been carried out via fluorescence microscopy, scanning electron microscopy (SEM), Focused Ion Beam (FIB) and atomic force microscopy (AFM). By and large, combining the programming ability of DNA as a scaffolding material with a one-step lithographic process, we have developed a platform of general applicability for the fabrication of nanoscale chips that can be employed in a variety of single-molecule investigations.
124

Selecting Surrogate Folds for Use in Origami-Based Mechanisms and Products

Allen, Jason Tyler 01 April 2017 (has links)
Origami-based design is increasing in popularity as its benefits and advantages become better understood and explored. However, many opportunities still exist for the application of origami principles to engineered designs, especially in the use of non-paper, thick sheet materials. One specific area utilizing thick sheet materials that is especially promising is origami-based mechanisms that require electrical power transfer applications. Many of these opportunities can be met by the use of surrogate folds. This thesis provides methods and frameworks that can be used by engineers to efficiently select and design surrogate folds for use in origami-based mechanisms and products. Surrogate folds are a means of achieving fold-like behavior, offering a simple method for achieving folding motions in thicker materials. A surrogate fold is a localized reduction in stiffness in a given direction allowing the material to function like a fold. A family of surrogate folds is reviewed, and the respective behaviors of the folds discussed. For a specified fold configuration, the material thickness is varied to yield different sizes of surrogate folds. Constraint assumptions drive the design, and the resultant configurations are compared for bending motions. Finite element and analytical models for the folds are also compared. Prototypes are made from different materials. This work creates a base for creating design guidelines for using surrogate folds in thick sheet materials. As mechanisms with origami-like movement increase in popularity, there is a need for conducting electrical power across folds. Surrogate folds can be used to address this need. Current methods and opportunities for conducting across folds are reviewed. A framework for designing conductive surrogate folds that can be adapted to fit specific applications is presented. Equations for calculating the electrical resistance in single surrogate folds as well as arrays are given. Prototypes of several conductive joints are presented and discussed. The framework is then followed in the design and manufacture of a conductive origami-inspired mechanism.
125

Metallization of Self-Assembled DNA Templates for Electronic Circuit Fabrication

Uprety, Bibek 01 June 2017 (has links)
This work examines the deposition of metallic and semiconductor elements onto self-assembled DNA templates for the fabrication of nanodevices. Biological molecules like DNA can self-assemble into a variety of complex 2-D and 3-D architectures without the need for expensive patterning tools. In addition, self-assembled DNA templates can be designed to controllably place functional nanomaterials with molecular precision. These characteristics make DNA an attractive template for fabricating electronic circuits from biological molecules. However, electrically conductive structures are required for electronic applications. While metallized DNA nanostructures have been demonstrated, the ability to make thin, continuous wires that are electrically conductive still represents a formidable challenge. DNA-templated wires have generally been granular in appearance with a resistivity approximately two to three orders of magnitude higher than that of the bulk material. An improved method for the metallization of DNA origami is examined in this work that addresses these challenges of size, morphology and conductivity of the metallized structure. Specifically, we demonstrated a metallization process that uses gold nanorod seeds followed by anisotropic electroless (autocatalytic) plating to provide improved morphology and greater control of the final metallized width of conducting metal lines. Importantly, growth during electroless deposition occurs preferentially in the length direction at a rate that is approximately four times the growth rate in the width direction, which enables fabrication of narrow, continuous wires. The electrical properties of 49 nanowires with widths ranging from 13 nm to 29 nm were characterized, and resistivity values as low as 8.9 x 10-7 Ω-m were measured, which represent some of the smallest nanowires and the lowest resistivity values reported in the literature. The metallization procedure developed on smaller templates was also successfully applied to metallize bigger DNA templates of tens of micrometers in length. In addition, a polymer-assisted annealing process was discovered to possibly improve the resistivity of DNA metal nanowires. Following metallization of bigger DNA origami structures, controlled placement of gold nanorods on a DNA breadboard (~100 x 100 nm2) to make rectangular, square and T-shaped metallic structures was also demonstrated. For site-specific placement of nanorods to a DNA template, we modified the surface of the gold nanorods with single-stranded DNA. The rods were then attached to DNA templates via complementary base-pairing between the DNA on the nanorods and the attachment strands engineered into the DNA "breadboard" template. Gaps between the nanorods were then filled controllably via anisotropic plating to make 10 nm diameter continuous metallic structures. Finally, controlled placement of metal (gold) - semiconductor (tellurium) materials on a single DNA origami template was demonstrated as another important step toward the fabrication of DNA-based electronic components. The combination of molecularly directed deposition and anisotropic metallization presented in this work represents important progress towards the creation of nanoelectronic devices from self-assembled biological templates.
126

Origami Reconfigurable Electromagnetic Systems

Yao, Shun 09 November 2017 (has links)
With the ever-increasing demand for wireless communications, there is a great need for efficient designs of electromagnetic systems. Reconfigurable electromagnetic systems are very useful because such designs can provide multi-functionality and support different services. The geometrical topology of an electromagnetic element is very important as it determines the element’s RF performance characteristics. Origami geometries have significant advantages for launch-and-carry electromagnetic devices where devices need to fold in order to miniaturize their size during launch and unfold in order to operate after the platform has reached orbit. This dissertation demonstrates a practical process for designing reconfigurable electromagnetic devices using origami structures. Four different origami structures are studied and the integrated Mathematical-Computational-Electromagnetic models of origami antennas, origami reflectors and origami antenna arrays are developed and analyzed. These devices provide many unique capabilities compared with the traditional designs, such as band-switching, frequency tuning, polarization adjustment and mode reconfigurability. Prototypes are also manufactured to validate the performances of the designs. These designs change their geometry naturally, and they can be compactly packaged into small volume, which make them very suitable for spaceborne and satellite communication. Origami antennas and origami electromagnetics are expected to impact a variety of applications related to communications, surveillance and sensing.
127

Origami Antennas for Novel Reconfigurable Communication Systems

Liu, Xueli 21 March 2018 (has links)
Antennas play a crucial role in communication systems since they are the transmitting/receiving elements that transition information from guided transmission to open-space propagation. Antennas are used in many different applications such as aerospace communications, mobile phones, TVs and radios. Since the dimensions of antennas are usually physically proportional to the wavelength at their operating frequencies, it is important to develop large antennas and arrays that can be stowed compactly and easily deployed. Also, it is important to minimize the number of antennas on a platform by developing multifunctional antennas. The first aim of this research is to develop new deployable, collapsible, light-weight and robust reconfigurable antennas based on origami principles. All designs will be validated through simulations and measurements. Paper as well as other substrates, such as, Kapton and fabric, will be used to develop our origami antennas. The second aim of this research is to derive integrated analytical and simulation models for designing optimal origami antennas for various applications, such as, satellite or ground communications. This dissertation presents research on origami antennas for novel reconfigurable communication systems. New designs of reconfigurable monofilar, bifilar and quadrifilar antennas based on origami cylinders are developed and validated. Novel fabrication methods of origami antennas are presented with detailed geometrical analysis. Furthermore, multi-radii origami antennas are proposed, analyzed, fabricated and validated and they exhibit improved circular polarization performance and wide bandwidths. An actuation mechanism is designed for these antennas. For the first time, a low-cost and lightweight reconfigurable origami antenna with a reflector is developed here. In addition, an array is developed using this antenna as its element. Finally, a kresling conical spiral antenna and a spherical helical antenna are designed with mode reconfigurabilities.
128

Packing Sheet Materials Into Cylinders and Prisms Using Origami-based Approaches

Bruton, Jared Thomas 01 August 2016 (has links)
Packing sheet materials into cylinders and prisms using Origami-based approaches (Soft Origami or traditional Origami) is of interest in fields where sheet materials need folded into cylinders or prisms. Fully-dense packing has application in fields where a sheet material is to be folded with minimal gaps into a cylinder or prism. Partially-dense packing is applicable to fields where gaps are required between packed surfaces or where hollow volumes are to be filled, such as in fluid filter design. Soft Origami is explored as a method for folding soft-sheet materials into fully-dense cylinders. Two fold patterns, the "flasher'' and the "inverted-cone fold,'' are explored for packing soft-sheet materials into cylindricals. An application to driver's side automobile airbags is successfully performed, and deployment tests are completed to compare the influence of packing method and origami pattern on deployment performance. In total, two origami patterns and six packing methods are examined for folding soft-sheet materials into fully-dense cylindrical prisms, and it is shown that modifying the packing method impacts deployment performance. A special case of the Miura-ori, the ninety-degree case, is briefly explored as a traditional Origami method for packing arbitrary-shaped sheet materials into fully-dense arbitrary prisms. Examples are shown and it is concluded that this pattern can be used to configure a large number of fully-dense packed prisms with configurable characteristics.Finally, patterns that fold into partially-dense cylindrical prisms are examined using traditional Origami approaches and their efficiency compared. Efficiency is defined as the ratio of the surface area of a pattern compared to an idealized high-surface-area model. Patterns include traditional (non-Origami-based) fluid filter patterns (the Basic Pleat and M-pleat) and cylindrical Origami patterns (the Accordion and Kresling). An offset crease method is used to modify the Accordion and Kresling Origami patterns so the comparison is objective. Results are presented that determine which individual pattern variations have the highest efficiency at different outside-to-inside diameter ratios. Ranges over which each pattern is most efficient are presented. It is concluded that based purely on geometry, the M-pleat provides the highest overall efficiency, but depending on other factors each pattern is viable for different purposes.
129

Advancing DNA-based Nanotechnology Capabilities and Applications

Marchi, Alexandria Nicole January 2014 (has links)
<p>Biological systems have inspired interest in developing artificial molecular self-assembly techniques that imitate nature's ability to harness chemical forces to specifically position atoms within intricate assemblies. Of the biomolecules used to mimic nature's abilities, nucleic acids have gained special attention. Specifically, deoxyribonucleic acid is a stable molecule with a readily accessible code that exhibits predictable and programmable intermolecular interactions. These properties are exploited in the revolutionary structural DNA nanotechnology method known as scaffolded DNA origami. For DNA origami to establish itself as a widely used method for creating self-assembling, complex, functional materials, current limitations need to be overcome and new methods need to be established to move forward with developing structures for diverse applications in many fields. The limitations discussed in this dissertation include 1) pushing the scale of well-formed, fully-addressable origami to two and seven times the size of conventional origami, 2) testing cost-effective staple strand synthesis methods for producing pools of oligos for a specified origami, and 3) engineering mechanical properties using non-natural nucleotides in DNA assemblies. After accomplishing the above, we're able to design complex DNA origami structures that incorporate many of the current developments in the field into a useful material with applicability in wide-ranging fields, namely cell biology and photonics.</p> / Dissertation
130

Dynamic DNA motors and structures

Lucas, Alexandra January 2016 (has links)
DNA nanotechnology uses the Watson-Crick base-pairing of DNA to self-assemble structures at the nanoscale. DNA nanomachines are active structures that take energy from the system to drive a programmed motion. In this thesis, a new design for a reversible DNA motor and an automatically regenerating track is presented. Ensemble fluorescence measurements observe motors walking along the same 42nm track three times. A second new motor was designed to allow motors on intersecting tracks to block each other, which can be used to perform logical computation. Multiple design approaches are discussed. The chosen approach showed limited success during ensemble fluorescence measurements. The 'burnt bridges' motor originally introduced by Bath et al. 2005 was also sent down tracks placed along the inside of stacked origami tubes that are able to polymerise to micrometre lengths. Preliminary optical microscopy experiments show promise in using such a system for observing micrometre motor movement. Scaffold-based DNA origami is the technique of folding a long single-stranded DNA strand into a specific shape by adding small staple strands that hold it in place. Extended staple strands can be modified to functionalise the origami surface. In this thesis, the threading of staple extensions through a freely-floating origami tile was observed using single-molecule Förster resonance energy transfer (smFRET). Threading was reduced by bracing the bottom of the extension or by using a multilayered origami. smFRET was also used to investigate the process of staple repair, whereby a missing staple is added to a pre-formed origami missing the staple. This was found to be successful when the staple is single-stranded, and imperfect when partially double-stranded. Finally the idea for a new "DNA cage", a dynamic octahedron called the "Holliday Octahedron", is presented. The octahedron is made of eight strands, one running around each face. Mobile Holliday junctions at each face allow the stands to rotate causing a conformational change.

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