Digital fabrication of custom interactive objects with rich materials

As ubiquitous computing is becoming reality, people interact with an increasing number of computer interfaces embedded in physical objects. Today, interaction with those objects largely relies on integrated touchscreens. In contrast, humans are capable of rich interaction with physical objects and their materials through sensory feedback and dexterous manipulation skills. However, developing physical user interfaces that offer versatile interaction and leverage these capabilities is challenging. It requires novel technologies for prototyping interfaces with custom interactivity that support rich materials of everyday objects. Moreover, such technologies need to be accessible to empower a wide audience of researchers, makers, and users. This thesis investigates digital fabrication as a key technology to address these challenges. It contributes four novel design and fabrication approaches for interactive objects with rich materials. The contributions enable easy, accessible, and versatile design and fabrication of interactive objects with custom stretchability, input and output on complex geometries and diverse materials, tactile output on 3D-object geometries, and capabilities of changing their shape and material properties. Together, the contributions of this thesis advance the fields of digital fabrication, rapid prototyping, and ubiquitous computing towards the bigger goal of exploring interactive objects with rich materials as a new generation of physical interfaces.Computer werden zunehmend in Geräten integriert, mit welchen Menschen im Alltag interagieren. Heutzutage basiert diese Interaktion weitgehend auf Touchscreens. Im Kontrast dazu steht die reichhaltige Interaktion mit physischen Objekten und Materialien durch sensorisches Feedback und geschickte Manipulation. Interfaces zu entwerfen, die diese Fähigkeiten nutzen, ist allerdings problematisch. Hierfür sind Technologien zum Prototyping neuer Interfaces mit benutzerdefinierter Interaktivität und Kompatibilität mit vielfältigen Materialien erforderlich. Zudem sollten solche Technologien zugänglich sein, um ein breites Publikum zu erreichen. Diese Dissertation erforscht die digitale Fabrikation als Schlüsseltechnologie, um diese Probleme zu adressieren. Sie trägt vier neue Design- und Fabrikationsansätze für das Prototyping interaktiver Objekte mit reichhaltigen Materialien bei. Diese ermöglichen einfaches, zugängliches und vielseitiges Design und Fabrikation von interaktiven Objekten mit individueller Dehnbarkeit, Ein- und Ausgabe auf komplexen Geometrien und vielfältigen Materialien, taktiler Ausgabe auf 3D-Objektgeometrien und der Fähigkeit ihre Form und Materialeigenschaften zu ändern. Insgesamt trägt diese Dissertation zum Fortschritt der Bereiche der digitalen Fabrikation, des Rapid Prototyping und des Ubiquitous Computing in Richtung des größeren Ziels, der Exploration interaktiver Objekte mit reichhaltigen Materialien als eine neue Generation von physischen Interfaces, bei

TOWARDS SYSTEMS ON CLOTH: THE DESIGN, MANUFACTURING, AND VALIDATION OF OPEN-SOURCE EMBROIDERED RESISTORS

This thesis is focused on advancing embroidered wearable electronics and textile electronics by creating open-source flexible resistors. Advancements in textile electronics could usher a new generation of smart devices that are entirely flexible. Current systems on cloth primarily use rigid components, which limits the flexibility and comfort of using the fabric devices. To advance this field, I propose a novel method of creating flexible electrical resistors with embroidery. To realize this technology, I created an open-source tool to create embroidery files for machine fabrication. This thesis details the methods and tools created for resistor fabrication. The resistors were tested to cover a range of conditions wearable electronic devices may be subjected to, then tested in an applied setting by being used in a touch sensing device. It is concluded that the embroidered resistors are a viable technology and warrant continued study, development, and use

Interactive tools for the preservation, dissemination and study of silk heritage : an introduction to the SILKNOW Project

Silk was a major factor for progress in Europe, mostly along the Western Silk Road's network of production and market centers. The silk trade also allowed for the exchange of ideas and innovations, having impacts at economic, technical, functional, cultural and symbolic levels. However, silk has today become a seriously endangered heritage. Although many European specialized museums are devoted to its preservation, they usually lack the size and resources to take advantage of state-of-the-art digital technologies. The aim of this paper is twofold; firstly, we introduce SILKNOW, an interdisciplinary project that has been recently funded by the H2020 Programme of the European Union in order to preserve and promote the heritage of silk textiles; secondly, we introduce a set of interactive tools related to the projec

Computational Design of Wiring Layout on Tight Suits with Minimal Motion Resistance

An increasing number of electronics are directly embedded on the clothing to monitor human status (e.g., skeletal motion) or provide haptic feedback. A specific challenge to prototype and fabricate such a clothing is to design the wiring layout, while minimizing the intervention to human motion. We address this challenge by formulating the topological optimization problem on the clothing surface as a deformation-weighted Steiner tree problem on a 3D clothing mesh. Our method proposed an energy function for minimizing strain energy in the wiring area under different motions, regularized by its total length. We built the physical prototype to verify the effectiveness of our method and conducted user study with participants of both design experts and smart cloth users. On three types of commercial products of smart clothing, the optimized layout design reduced wire strain energy by an average of 77% among 248 actions compared to baseline design, and 18% over the expert design.Comment: This work is accepted at SIGGRAPH ASIA 2023(Conference Track

A System for Programming Anisotropic Physical Behaviour in Cloth Fabric

We propose a method to alter the tensile properties of cloth in a user defined and purposeful manner with the help of computer controlled embroidery. Our system is capable of infusing non-uniform stiffening in local regions of the cloth. This has numerous applications in the manufacturing of high performance smart textiles for the medical industry, sports goods, comfort-wear, etc where pressure needs to be redistributed and the cloth needs to deform correctly under a given load. We make three contributions to accomplish this: a decomposition scheme that expresses user-desired stiffness as a density map and a directional map, a novel stitch planning algorithm that produces a series of stitches adhering to the input stiffness maps and an inverse design based optimization driven by a cloth simulator that automatically computes stiffness maps based on user specified performance criteria. We perform multiple tests on physically manufactured cloth samples to show how embroidery affects the resultant fabric to demonstrate the efficacy of our approach

Multiscale modelling of woven and knitted fabric membranes

Light-weight fabric membranes have gained increasing popularity over the past years due to their tailorable structural and material performances. These tailorable properties include stretch forming and deep drawing formability that exhibits excellent stretchability and drapeability properties of textiles and textile composites. Since the inception of computerised numerical control for three-dimensional textile-manufacturing machines, technical textiles paved their way to numerous applications, certainly not limited to; aerospace, biomedical, civil engineering, defence, marine and medical industries. Digital interlooping and digital interlacing technology in additive manufacturing greatly advanced the manufacturing processes of textiles. In this work, we consider two branches of technical fabrics, namely plain-woven and weft-knitted. Multiscale modelling is the tool of choice for homogenising periodic structures and has been used extensively to model and analyse the mechanical behaviour of woven and knitted fabrics. But there is a plethora of literature discussing the demerits of such conventional multiscale modelling. These demerits include higher computational costs, rigid numerical models, ineffcient algorithmic computations and inability to incorporate geometric nonlinearities. We propose a data-driven nonlinear multiscale modelling technique to analyse the complex mechanical behaviour of plain-woven and weft-knitted fabrics with a neat extension to fabric material designing. We show how the integration of statistical learning techniques mitigates the weaknesses of conventional multiscale modelling. Moreover, we discuss the avenues that will open in many potential fields with regard to material modelling, structural engineering and textile industries. In the proposed data-driven nonlinear computational homogenisation technique, we effi ciently integrate the microscale and macroscale using Gaussian Process Regression (GPR) statistical learning technique. In the microscale, representative volume elements (RVEs) are modelled using nite deformable isogeometric spatial rods and deformation is homogenised using periodic boundary conditions. This nite deformable rod is profi cient in handling large deformations, rod-to-rod contacts, arbitrary cross-section de finitions and follower loads. Respecting the principle of separation of scales, we construct response databases by applying different homogenised strain states to the RVEs and recording the respective incremental volume-averaged energy values. We use GPR to learn a model using a 5-fold cross-validation technique by optimising the log marginal likelihood. In the macroscale, textiles are modelled as nonlinear orthotropic membranes for which the stresses and material constitutive relations are predicted by the trained GPR model. This coupling between GPR and membrane models is achieved through a systematic and seamless nite element integration using C++ and Python environments. A neat extension to material designing is also discussed with potentials to extend the work into other related fi elds.Cambridge trust and Trinity Hall scholarshi

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

The application of new technologies in fashion and implementation of additive manufacturing in the apparel industry

The most diverse sectors were influenced by the democratisation of 3D printers. This is why fashion designers try to apply 3D printing to their creations and look for a viable way to implement the technique. The adoption of 3D printing on apparel not only brings new advantages but also changes the entire manufacture of the product and the design development, as well as the relationship with the consumer. The application of fashionable printing is still very much focused on accessories and footwear, yet to bring innovation. There is still a need to launch new materials and introduce more technologies, representing what many see as part of the fourth industrial revolution in the context of fashion, where smart or wearable textiles win more and more space in the market, and prosumers increase every day. While the introduction of this technique in the fashion industry is recent compared to the traditional methods of garment manufacturing, there has been significant progress and a growing number of enthusiastic designers who try to develop this type of product. However, while there are many materials designed for printing and designers to develop their parts, there is a recurring problem that translates into the rigidity of the components obtained and, consequently, the lack of comfort and usability. That is why 3D printing has developed more rapidly in the accessory industry (jewellery, bags ...). After extensive research on additive manufacturing technologies and its application in the fashion industry, it was possible to verify that footwear, jewellery, and other accessories were the ones that had better adherence. It was also observed that in the clothing sector the technology is still very much linked to conceptual fashion and that there are several obstacles to the implementation of the technique. It is also clear that there is a long way to go about the feasibility of solutions for the manufacture and the need to find means that allow more flexible and comfortable parts of good quality and with ample movement. It is necessary to have a material innovation that enables the creation of pieces in which comfort, mobility, and flexibility are prioritised since designers do not prioritise only the aesthetic appeal, but also the function and usability of the object. My project aims to address precisely the application of fashionable additive manufacturing and get a new approach on the materials used, the forms and machines for creating textiles and then clothing, to make the daily life of these pieces more viable.Os setores mais diversos foram influenciados pela democratização das impressoras 3D. Por essa razão os designers de moda tentam aplicar a impressão 3D às suas criações e procuram uma maneira viável de implementar a técnica. A adoção da impressão 3D no vestuário não apenas traz novas vantagens, mas também altera todo o fabrico do produto e o método de design, bem como o relacionamento com o consumidor. A aplicação da impressão na moda ainda é muito focada em acessórios e calçado, contudo para trazer inovação, é necessário lançar novos materiais e introduzir mais tecnologias, representando o que muitos consideram parte da quarta revolução industrial no contexto da moda, onde têxteis inteligentes ou vestíveis ganham cada vez mais espaço no mercado e os “prosumidores” aumentam a cada dia. Embora a introdução desta técnica na indústria da moda seja recente em comparação com os métodos tradicionais de fabricação de vestuário, houve um progresso significativo e um número crescente de designers entusiastas que tentam desenvolver este tipo de produto. No entanto, embora existam muitos materiais desenvolvidos para impressão e designers para desenvolver suas peças, há um problema recorrente que se traduz na rigidez das peças obtidas e, consequentemente, na falta de conforto e usabilidade. É por isso que a impressão 3D se desenvolveu mais rapidamente na indústria de acessórios. Após uma extensa pesquisa sobre tecnologias de manufatura aditiva e sua aplicação na indústria da moda, foi possível verificar que calçados, joias e outros acessórios foram os que tiveram melhor aderência. Observou-se também que no setor de vestuário a tecnologia ainda está muito ligada à moda conceitual e que existem vários obstáculos para a implementação da técnica. No entanto há ainda um longo caminho a percorrer em relação à viabilidade de soluções para a confeção e a necessidade de encontrar meios que permitam partes mais flexíveis e confortáveis de boa qualidade e com amplo movimento. É necessário ter uma inovação material que permita a criação de peças nas quais o conforto, o movimento e a flexibilidade sejam priorizados, uma vez que os designers não priorizam somente o apelo estético, mas também a função e usabilidade do objeto. Este projeto visa abordar precisamente a aplicação de manufatura aditiva na moda e obter uma nova abordagem sobre os materiais utilizados, as formas e as máquinas para criação de têxteis e posteriormente vestuário, de forma a tornar mais viável o quotidiano destas peças