Sliceforms: Deployable structures from interlocking slices

A sliceform is a volumetric, honeycomb-like structure assembled from an array of cross-sectional planar slices that are interlocked via pairs of complementary slots placed along each intersection. If the slices are thin, these slotted intersections function as revolute joints, and the sliceform is foldable if the geometry of the embedded spatial linkage permits it, for example a lattice sliceform (LS) is bi-directionally flat-foldable. This thesis concerns a study of such sliceforms toward the design of novel deployable structures. A sliceform torus, composed of two sets of inclined slices arranged at regular intervals about a central axis of symmetry, has been discovered to exhibit a surprising and intriguing folding action whereby its incomplete form can be collapsed to a flat-folded stack of coplanar slices. On deployment, the assembly expands smoothly about an arc until the slices have rotated to their design inclination, then, without reaching any apparent physical limit, abruptly ‘locks out’. With a full complement of slices, the outermost intersections can be interlocked to complete and rigidify the ring. The torus is an example of a rotational sliceform (RS), and analysis of these structures proceeds by noting that their structural geometry comprises an array of pyramidal cells that is commensurate to a spherical scissor grid. The conditions for flat-foldability are determined by examination of the intrinsic geometry of each cell; the incompatibility of the slices with apparent rigid-folding revealed by assessment of the extrinsic motion of the slices. Investigation of their compliant kinematics reveals the articulation to be a bistable transition admitted by small transverse deflections of the slices. This structural form is generalised by development of a technique for generating sliceforms along a smooth spatial curve – curve sliceforms (CS). Their synthesis is more involved than for an RS, but a range of sliceform ‘tubes’ are generated and manufactured. Each example retains the flat-foldable, deployable characteristic of an RS, despite the apparent intrinsic rigidity of each constituent skew cell. Examination of the small-scale models indicates that deployable motion is achieved via imperfect action of the slots, and a simple model of the articulation of a single cell is constructed to investigate how this proceeds, verifying that motion is kinematically admissible via local deformations

Water-soluble rotaxanes : identifiying suitable building blocks for molecular daisy chains

Structurally diverse rotaxane-based systems have been investigated extensively for applications as molecular machines and functional nanomaterials. Although the vast majority of functional molecules were assembled and function in organic solvents, to date the most efficient and sophisticated molecular machines are biomolecules which function in aqueous media. Many vital processes, such as protein folding and assembly, rely on hydrophobic interactions and are only possible in aqueous environment. From a supramolecular chemistry perspective, the hydrophobic effect is an appealing driving force for host-guest association as it potentially leads to high complexation affinities and no extra binding sites need to be installed into the respective components. Appealing macrocyclic candidates for the preparation of mechanically interlocked molecules in aqueous media are the synthetically modifiable, water-soluble cyclophanes developed and comprehensively studied by Diederich et al.. The focus of this doctoral thesis was to identify suitable guest molecules for Diederich-type cyclophanes, allowing for the assembly of rotaxanes and also molecular daisy chains. The first part of the thesis describes the investigation of the aggregation behavior of amphiphiles based on OPE guests which are potentially capable of forming molecular daisy chains (Chapter 2). A deeper insight into the system was obtained through a series of rotaxane model compounds, basically relying on the main components of the previously examined amphiphiles (Chapter 3). The investigation of an extended scope of potential guest molecules via 1H NMR complexation studies resulted in an optimization of the molecular guest design and revealed some important features of suitable candidates (Chapter 4). Based on these results a water-soluble 2,6-disubstituted naphthalene derivative was found to function as (pseudo)rotaxane axle and enabled the isolation and characterization of a [2]rotaxane (Chapter 5). The results obtained throughout this doctoral thesis allow to obtain guidelines for the successful preparation of interlocked molecular daisy chains

Microscopic evaluation of two-photon activated molecular nanomachines for next generation targeted cancer therapeutics

Unidirectional molecular nanomachines are small organic molecules consisting of two distinct halves; a stator, and rotor, connected by a sterically overcrowded carbon-carbon double bond. When excited with specific wavelengths of light, commonly used 355 and 365 nm, a cis-trans isomerisation occurs, resulting in a unidirectional 360° rotary mechanism capable of overcoming Brownian motion. This has previously been exploited to mechanically damage the outer membranes of cells, triggering an acceleration of irreversible necrotic cell death. Herein a series of systematic live-cell fluorescence microscopy studies are reported evaluating the capability of new functionalised molecular nanomachines to induce premature cell death. Specifically, work has been carried out to develop methodology and instrumentation capable of activating these molecules with more biologically favourable NIR wavelengths by way of two-photon activation - utilising pulsed (fs) laser light. In addition, experiments aimed at assessing newly developed families of molecular nanomachines capable of crossing the phospholipid bilayer and activating confined and controlled rotary mechanism from within the cell are presented. Key findings are presented showing how functionalisation of molecular nanomachines, with diamine moieties of various levels of methyl substitution, is able to induce a bathochromic shift in activation wavelength. Specifically, a greater level of amine substitution by electron donating alkyl chains is shown to increase this effect when attached to the rotor half of the nanomachine. Activation of polyethylene glycol functionalised nanomachines by way of a two-photon process is also illustrated both when in solution and, importantly, from within the cell. This is also extended to nanomachines functionalised with the mitochondrial targeted triphenylphosphine addend. These developments are then combined. Using attempts to activate internalised molecular nanomachines functionalised with triphenylphosphine from withinside cells. Specifically using therapeutically favourable, less phototoxic, 710 nm NIR wavelengths to induce more biologically compatible routes towards cell death, such as apoptosis. Miscopy images are presented illustrating that with the combination of these techniques, with short precisely designed windows of laser exposure, it is possible to observe clear morphological features of cell death without the addition of fluorescent signs of necrosis. These results represent a significant step forward towards the development of next generation targeted cancer therapeutics, but also leave a clear avenue for further work within the field. Suggestions are presented on how to extend this research, specifically on methods to measure the multiphoton cross section of photomechanical compounds, such as molecular nanomachines, more accurately. As well as methods for measuring apoptosis caused by nanomechanical damage, and importantly, how to distinguish this from necrotic processes

Lineages of the Hegemon - Constructing Dutch Hegemony, XIV-XVII

It is a study aiming at understanding the historical development of a world power within the capitalist world-system , which is also a would-be general perspective or framework of analysis to fathom how a world hegemon emerges out of the history of its own. In a nutshell: it is to be argued that the hegemon is a regime of accumulation wherein state, capital and society work hand in glove with a particular degree of coherence developed within the legal boundaries of its territorial sovereignty. This internal structure of power breeds hegemony, that is, the projection of power unto and onto world space, and into the international system of states and markets. Hence, this study represents an attempt to glean the connection between the internal composition of a regime of accumulation and the propensity and force of the same regime to expand its scale and scope of operation in world space – what Joshua Goldstein calls «lateral pressure» . However, what will be essayed is not the customary inquiry into the projection of power onto the system which a powerful regime engendered, and whose manifestation is what we call hegemony, but an investigation into the inner source and morphology of power whence such a projection primary feeds off. The nub of this study is the hegemon: to understand its path of development, its composition and how it works. More to the point, we will delve into Dutch history to substantiate historically such a perspective. At the end of the sixteenth century a new state called United Provinces stepped into the limelight of European and world history. It emerged out of the war for the independence from the most powerful Empire of the early modern era, the Spanish world power. This war contributed to shape Dutch history. But the United Provinces were more than a development of the sixteenth century. Their historical complexion, as it is to be argued, originated from a past made of unruly ecology and incipient ecological and human commodification. The historical foundations – not their operational organization – arose during the late middle ages, and more precisely in the span of time that went from the XIV to the XVI century. The Dutch Republic, as it was called, became thereby the first hegemon of the modern era through the organized expansion and sovereign structuring of the medieval space of wealth, accumulation and power. In particular, it was the first hegemon of the modern world-system, a capitalist world-economy, the current world historical-social system . The present study is, in general, a very long-run analysis and synthesis of Dutch history to understand the overall movement of power, wealth and capital that characterized the Northern Low Countries from the XIV century to the XVII. The analysis will focus on the power relations, structures, processes, networks, institutions, agents and agencies which developed, operated and changed during this span of tim

On toroidal knots, chirality, and molecules

The inspiration for this thesis came from two sources: the book When topology meets chemistry: a topological look at molecular chirality, by Erica Flapan [7], which discusses topologically interesting molecules; and the paper All toroidal embeddings of polyhedral graphs in 3-space are chiral, by T. Castle et al., which proves that toroidal embeddings of polyhedra are chiral. Their proof is examined in detail. A possible application of this work, as discussed by the team, would be in molecules which have the structure of a toroidal polyhedral embedding. Various methods of seeking such an example are attempted and discussed

Towards a Semantic Knowledge Management Framework for Laminated Composites

The engineering of laminated composite structures is a complex task for design engineers and manufacturers, requiring significant management of manufacturing process and materials information. Ontologies are becoming increasingly commonplace for semantically representing knowledge in a formal manner that facilitates sharing of rich information between people and applications. Moreover, ontologies can support first-order logic and reasoning by rule engines that enhance automation. To support the engineering of laminated composite structures, this work developed a novel Semantic LAminated Composites Knowledge management System (SLACKS) that is based on a suite of ontologies for laminated composites materials and design for manufacturing (DFM) and their integration into a previously developed engineering design framework. By leveraging information from CAD/FEA tools and materials data from online public databases, SLACKS uniquely enables software tools and people to interoperate, to improve communication and automate reasoning during the design process. With SLACKS, this research shows the power of integrating relevant domains of the product lifecycle, such as design, analysis, manufacturing and materials selection through the engineering case study of a wind turbine blade. The integration reveals a usable product lifecycle knowledge tool that can facilitate efficient knowledge creation, retrieval and reuse, from design inception to manufacturing of the product

New Designs for Wearable Technologies: Stretchable e-Textiles and e-Skin

This dissertation comprises research efforts in addressing the challenges of integration of different materials with mechanical mismatches in stretchable e-textiles and e-skin, with a major focus on the design and fabrication of stretchable e-textiles. Chapter 2 describes the solution-based metallization of a knitted textile that conformally coats individual fibers with gold, leaving the void structure intact. The resulting gold-coated textile is highly conductive, with a sheet resistance of 1.07 ohm/sq in the course direction. The resistance decreases by 80% when the fabric is stretched to 15% strain and remains at this value to 160% strain. This outstanding combination of stretchability and conductivity is accompanied by durability to wearing, sweating, and washing. Low-cost screen printing of a wax resist is demonstrated to produce patterned gold textiles suitable for electrically connecting discrete devices in clothing. The fabrication of electroluminescent fabric by depositing layers of device materials onto the gold-coated textile is furthermore demonstrated, intimately merging device functionality with textiles for imperceptible wearable devices. Chapter 3 presents a new textile-centric design paradigm in which we use the textile structure as an integral part of wearable device design. Coating the open framework structure of an ultrasheer knitted textile with a conformal gold film using solution-based metallization forms gold-coated ultrasheer electrodes that are highly conductive (3.6 ± 0.9 ohm/sq) and retain conductivity to 200% strain with R/R0 \u3c 2. The ultrasheer electrodes produce wearable, highly stretchable light-emitting e-textiles that function to 200% strain. Stencil printing a wax resist provides patterned electrodes for patterned light emission; furthermore, incorporating soft-contact lamination produces light-emitting textiles that exhibit, for the first time, readily changeable patterns of illumination. Chapter 4 demonstrates the strategic use of a warp-knitted velour fabric in an “island-bridge” architectural strain-engineering design to prepare stretchable textile-based lithium ion battery (LIB) electrodes. The velour fabric consists of a warp-knitted framework and a cut pile. We integrate the LIB electrode into this fabric by solution-based metallization to create the warp-knitted framework current collector “bridges”, followed by selectively deposition of the brittle electroactive material CuS on the cut pile “islands”. As the textile electrode is stretched, the warp-knitted framework current collector elongates, while the electroactive cut pile fibers simply ride along at their anchor points on the framework, protecting the brittle CuS coating from strain and subsequent damage. The textile-based stretchable LIB electrode exhibited excellent electrical and electrochemical performance with a current collector sheet resistance of 0.85 ± 0.06 ohm/sq and a specific capacity of 400 mAh/g at 0.5 C for 300 charging-discharging cycles, as well as outstanding rate capability. The electrical performance and charge-discharge cycling stability of the electrode persisted even after 1000 repetitive stretching-releasing cycles, demonstrating the protective functionality of the textile-based island-bridge architectural strain-engineering design. Chapter 5 demonstrates the engineering of metal cracking patterns using the topography from acid-oxidized PDMS. Oxidizing the surface of PDMS with aqueous acid mixture created hierarchical topographies. Coating the surface of acid-oxidized PDMS with copper using electroless deposition produced stretchable conductors with a sheet resistance of ~1.2 ohm/sq. The cracking patterns of copper films with strain were tuned by simply adjusting the composition of acid mixture to change the topography of PDMS, which affects the resistance change of copper films with strain. The Cu films with an optimal cracking pattern on acid-treated PDMS remain conductive to 85% strain with R/R0 less than 20

Bio-Inspired Synthesis Of Nanostructured Materials On Substrates For Environmental And Energy Applications

It is still a challenging task to develop simple methods for facile synthesis of functional nanostructures on substrates under mild conditions without using expensive instruments. We have successfully developed a bio-inspired method using simple diaphragm-assisted system to synthesize functional nanostructures on various substrates under mild conditions. We have systematically studied the effects of experimental parameters on the formation of nanostructures under controlled conditions. The fundamental mechanism involved has been systematically studied and revealed. By growing the unique networks of nanostructures on a piece of substrate, a double-rough surface, with structures at both nanoscale and microscale, has been achieved, showing interesting roughness-induced superhydrophobicity in air and superoleophobicity in water. The double rough substrates will find important environmental applications. Additionally, nanostructures formed on substrates have been used as integrated and binder-free electrodes for energy storage. The unique structures with a large exposed surface enable the electrodes to demonstrate dramatically improved performances. Moreover, some chemically active substrates were used to build up composite materials to enhance their applications. The method and ideas outlined in the dissertation, based on diaphragm-assisted systems, will have impacts, in principle, on the synthesis of numerous functional materials or precursors under mild conditions

Innovative Tokyo

This paper compares and contrasts Tokyo's innovation structure with the industrial districts model and the international hub model in the literature on urban and regional development. The Tokyo model embraces and yet transcends both industrial districts and international hub models. The paper details key elements making up the Tokyo model-organizational knowledge creation, integral and co-location systems of corporate R&D and new product development, test markets, industrial districts and clusters, participative consumer culture, continuous learning from abroad, local government policies, the national system of innovation, and the historical genesis of Tokyo in Japan's political economy. The paper finds that the Tokyo model of innovation will continue to evolve with the changing external environment, but fundamentally retains its main characteristics. The lessons from the Tokyo model is that openness, a diversified industrial base, the continuing development of new industries, and an emphasis on innovation, all contribute to the dynamism of a major metropolitan region.Labor Policies,Environmental Economics&Policies,Public Health Promotion,ICT Policy and Strategies,Agricultural Knowledge&Information Systems,ICT Policy and Strategies,Environmental Economics&Policies,Health Monitoring&Evaluation,Agricultural Knowledge&Information Systems,Innovation