Metal and semiconducting nanocrystals have received a great deal of attention from fundamental scientists and application-oriented researchers due to their physical and chemical properties, which differ from those of bulk materials. Nanocrystals are essential building blocks in the development of nanostructured devices for energy conversion. Colloidal metals and metal chalcogenides have been developed for use as nanocrystal inks to produce efficient solar cells with lower costs. All high-performing photovoltaic nanocrystals contain toxic elements, such as Pb, or scarce elements, such as In; thus, the production of solution-processable nanocrystals from earth-abundant materials using environmentally benign synthesis and processing methods has become a major challenge for the inorganic semiconductor-based solar field. This dissertation, divided into two parts, addresses several aspects of these emerging challenges. The first portion of the thesis describes the synthesis and characterization of nanocrystals of antimony sulfide, which is composed of non-scarce and non-toxic elements, and examines their performance in photovoltaic devices. The effect of various synthetic parameters on the final morphology is explored. The structural, optical and morphological properties of the nanocrystals were investigated, and Sb2S3 nanocrystal-based solid-state semiconductor-sensitized solar cells were fabricated using different deposition processes. We achieved promising power conversion efficiencies of 1.48%. The second part of the thesis demonstrates a novel method for the in situ synthesis and patterning of nanocrystals via reactive inkjet printing. The use of low-cost manufacturing approaches for the synthesis of nanocrystals is critical for many applications, including photonics and electronics. In this work, a simple, low-cost method for the synthesis of nanocrystals with minimum size variation and waste using reactive inkjet printing is introduced. As a proof of concept, the method was used for the in situ synthesis of gold nanoparticles as a model system. Relatively monodisperse gold nanoparticles were produced. The size and shape of gold nanoparticles can be controlled by the gold precursor and surfactant concentration in the ‘ink.’ This approach can be extended to the synthesis of other nanocrystals and is thus a truly impactful process for the low-cost synthesis of materials and devices incorporating nanocrystals.

This thesis represents a major contribution to wideband and high gain inkjet-printed antennas on paper. This work includes the complete characterization of the inkjet printing process for passive microwave devices on paper substrate as well as several ultra-wideband and high gain antenna designs. The characterization work includes the electrical characterization of the permittivity and loss tangent for paper substrate through 10 GHz, ink conductivity data for variable sintering conditions, and minimum feature sizes obtainable by today’s current inkjet processes for metallic nanoparticles. For the first time ever, inkjet-printed antennas are demonstrated that operate over the entire UWB band and demonstrate gains up to 8dB. This work also presents the first fractal-based inkjet-printed antennas with enhanced bandwidth and reduced production costs, and a novel slow wave log periodic dipole array which shows minimizations of 20% in width over conventional log periodic antennas.

No description available.

The subject of this diploma thesis is the preparation of conductive structures by electroless plating of an extruded precursor. The experimental part deals with the preparation of standard patterns based on the length of immersion time in a coppering bath. The precursor layers were applied with Fujifilm Dimatix to various receiver substrates. The individual substrates with the precursor layer were immersed in the copper solution within different time intervals. The structure of the layers of grown copper and their thickness was characterized by a profilometer.

The thesis considers a change in the manufacturing technology of a fan impeller from welding to 3D printing. The wish of the manufacturer was to investigate if such a change is possible and financially profitable and decide on a further approach to manufacturing. Models were created using information from the manufacturer and using them, conditions for manufacturing the impeller in the 1:1 ratio were derived. Based on the new technological process and the experience from prints a new price calculation for the fan impeller using 3D printing was created.

Minimally invasive spine surgery (MISS) has proven to be advantageous over traditional open surgery as it minimizes the likelihood of tissue damage and infections. During MISS, surgeons create small incisions to allow access to the surgery site, however, opting for smaller incisions decreases the surgeon’s field of vision. To compensate, surgeons rely on preoperative and intraoperative ionizing imaging technologies for guidance. Conventional localization of the spine, registration of digital images to the patient during surgery, depends heavily on the surgeon’s anatomical knowledge and their experience. Preoperative images are typically created using 3D technology while intraoperative images use 2D technology. While the integration of preoperative 3D images and intraoperative 2D images can provide valuable assistance, patient’s preoperative and intraoperative positions do not coincide leading to additional use of ionizing imaging. The objective of this research was to propose a workflow that assists with image registration for MISS. The main component of the workflow was the creation of a script that automatically generates patient-specific digital guides, which will then be manufactured, to align the patient’s intraoperative and preoperative body position. By aligning the patient’s positions, the 3D printed surgical guide serves as a shared feature between the preoperative digital image and the actual patient. This allows for the intraoperative image to be registered to the preoperative image more accurately. Additionally, the guide acts as an attachment site for any additional instrument guides/supports. The surgical guide generating script utilizes the skin contour of patient’s torso region, extracted from medical images, to automatically produce the guide’s horizontal and vertical components. Adjustments are made to the components using CAD software before proceeding to manufacturing, via 3D printing, and assembly of the guide. To validate the workflow, more specifically the script’s ability to automatically generate surgical guides that fit over the patient’s back, a guide was created for a mannequin. The maximum gap between the mannequin and the horizontal components was 0.8 cm and 1.5 cm for the vertical component.

<p>A key aspect of color change is altering perceived value or intensity. This dissertation presents a methodology to achieve value change through mechanical means via the deflection of bistable structures. We create the Mechxel, two methods of mechanical pixel-based, reversible color change using 3D printed switchable multistability and bistable switch panels that augment the projected area a viewer perceives which enables the creation of image and character tessellation.</p> <p>Switchable multistability (SMS) arises from the combination of pre-strain and shape memory, allowing us to access multiple elastically programmed shapes at elevated temperatures with fast morphing and low actuation forces, while retaining high stiffness at room temperature. We design and manufacture SMS Mechxels using fused deposition modeling (FDM) 3D printing on the Ultimaker 3D printer in a bilayer layup of polylactic acid (PLA) with a [90/0] print direction while iteratively miniaturizing the physical size to enhance the resolution while also reducing the size of the overall tessellated display. Leveraging SMS properties programmed into each Mechxel, the projected area to a viewer will vary between the unit’s stable states, creating a difference in perceived value of coloration due to changes in area. To ease the tessellation process, we also introduce a tessellation user interface that maps images to their tessellated equivalent to reduce tessellation trial and error. This interface also calculates the number of Mechxels required in their respective states and the final physical size of the display. We then carry out image processing to justify this change in value between stable states and run preliminary optical character recognition.</p> <p>Inspired by mechanical bistable mechanisms, the bistable switch Mechxels utilize changes in a surface’s projected area to a viewer via changes in the angle of a bistable tile using a 5-by-5 grid for character replication and display. Comprising of three main components – two bistable switches, a colored tile and a base, design considerations were made to create an easy to assemble and replaceable 3D printed grid system that could be interacted with by audiences or easily electromechanically actuated. Using pixel-by-pixel comparisons and Sorensen-Dice coefficient, characters using the typeface Silkscreen were documented on these tiled grids yielding high similarity and low error when compared to their digital reference images in various positions and orientations. We also experiment with transitional waves as a promising means of actuation to change the Mechxel between their stable states.</p> <p>The Mechxels considered in this research introduce a new means of purely mechanical color change, character, and image display either leveraging the elastic properties of shape memory polymers (SMPs) or bistable mechanisms. With potential applications in passive morphing architecture, adaptive camouflage, and interactive aesthetic, Mechxels opens the door to limitless design possibilities through a new perspective into color change.</p>

In this report, my work on 3D-printing will be presented. This project is what constitutes my examination project in the education of industrial design engineering.   3D-printers are tools that have undergone great development in recent years. Through this development, the machines have become increasingly accessible to private individuals thanks to reduced prices, easyer use and higher quality. Through an increased use of the tool on a more private level, new opportunities are created for how we manufacture products, as well as how our attitude to its components are viewed.   The purpose of the work was to investigate how 3D-printing can be used to create more efficient and sustainable products with a focus on users, manufacturers and the environment. The goal was to develop an approach to utilize the function of a 3D-printer in a way that contributes to higher sustainability and efficiency, where the end result should contribute to this without forcing the user to make any decisive sacrifices.   The work has been carried out with a three-part process, divided into the phases Inspiration, Ideation and implementation, which together constitute an iterative design process. Initially in the inspiration phase, inspiration was created for the work with the help of a literature study, theory collection and a context analysis. Then began the ideation phase, whose purpose was to start creating ideas and conceptualize the inspiration that has previously been collected in the inspiration phase. To implement these ideas and concepts, the implementation phase was carried out to achieve a more completed and implemented concept.   The work resulted in the concept TonePrint. TonePrint is a speaker and a pair of headphones that work together in a form of ecosystem to make the interaction smoother for the user when changing audio source. The product TonePrint is a product that the user 3D-prints by oneself. This contributes to a more efficient and sustainable product as well as production. The product is designed in a way that enables the user to configure the product based on their own needs, which contributes to increased personalization. It allows the user to reuse components from previous devices that would otherwise be discarded, or select components based on their own liking and taste. / I den här rapporten kommer mitt arbete rörande 3D-printeing presenteras. Det här projektet är det som utgör mitt examensarbete i utbildningen högskoleingenjör inom teknisk design.   3D-printers är verktyg som har genomgått stor utveckling de senaste åren. Genom den här utvecklingen har maskinerna blivit allt mer tillgängliga för privatpersoner tack vare lägre priser, smidigare användning och högre kvalitet. Genom en ökad användning av verktyget på mer privata plan skapas nya möjligheter för hur vi tillverkar produkter, samt hur vi ser på produkter och dess uppbyggande komponenter.   Syftet med arbetet var att undersöka hur 3D-printing kan användas för att skapa mer effektiva och hållbara produkter med fokus på användare, tillverkare och miljön. Målet var att ta fram ett tillvägagångssätt att nyttja de egenskaper en 3D-printer medför på ett sätt som bidrar till en högre hållbarhet och effektivitet, där det slutliga resultatet ska bidra till detta utan att tvinga användaren att göra några avgörande uppoffringar.    Arbetet har genomförts med en tre delad process, indelad i faserna Inspiration, Ideation och implementation som tillsammans utgör en iterativ designprocess. Initialt i inspirationsfasen skapades inspiration för arbetet med hjälp av en litteraturstudie, teoriinsamling samt en kontextanalys. Därefter påbörjades ideationsfasen, vars syfte var att börja skapa idéer och konceptualisera den inspirationen som tidigare blivit insamlad i inspirationsfasen. För att implementera dessa idéer och koncept utfördes implementationsfasen för att nå ett mer färdigställt och förverkligat koncept.   Arbetet resulterade i konceptet TonePrint. TonePrint är en högtalare och ett par hörlurar som samverkar i ett form av ekosystem för att göra interaktionen smidigare för användaren vid byte av ljudkälla. Produkten TonePrint är en produkt som användaren själv 3D-printar. Detta bidrar till en mer effektiv och hållbar produkt samt produktion. Produkten är utformad på ett sätt som möjliggör för användaren att konfigurera produkten utifrån eget behov vilket bidrar till en ökad personalisering. Det möjliggör för användaren att återanvända komponenter från tidigare enheter som annars skulle slängas, eller välja komponenter utifrån eget tycke och smak.

Measurement of circulating protein biomarkers associated with disease can facilitate early detection, help guide treatment strategies and improve patient outcomes beyond current standards of care. The combination of inexpensive 3D-printed flow cells and electrochemical biosensors has recently emerged as a viable platform for low-cost, reliable biomarker measurements. Here, we report an electrochemical immunoassay system based on simple graphite electrode arrays, 3D-printed flow cells, and signal-generating magnetic bead bioconjugates for simultaneous detection of three biomarker proteins (cancer antigen 125 (CA-125), midkine (MK) and osteopontin (OPN)) associated with pediatric soft tissue sarcomas (PSTS). Magnetic bead bioconjugates are functionalized with large amounts of antibody and enzyme labels, electrode arrays are modified with gold nanoparticles and antibodies for specific capture of bioconjugate-labeled biomarkers, and 3D-printed flow cells facilitate their amperometric detection. Using this system, detection limits for CA-125, OPN and MK are 100 times lower than those obtained with commercial enzyme-linked immunosorbent assay (ELISA).

The diploma thesis deals with light dosimeters and modern printing and coating techniques for thin-film formation. The subject of experimental study is the optimization of photosensitive compositions for the preparation of disposable, printed and thin-film dosimeters for visible light. Sensitivity, reproducibility and irreversibility of their color change were optimized. Compositions were calibrated for desired light dose. Functional samples for gallery were fabricated and stability of functional samples were tested at high temperatures of storing.