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Environmental issues related to the Electronic and Electrical Equipment industry lead companies to consider a new sustainability model to decouple economic growth from resource consumption and waste generation. A significant body of literature focuses on materials and process innovation in the field of Printed Circuit Board (PCB), simultaneously limited attention has been given to industry practices and circular economy strategies. This study aims to contribute insights into sustainable circular economy practices in the PCB industry; it examines the current integration of sustainability and circularity principles in PCB companies in Sweden and assesses the associated strengths, weaknesses, opportunities, and threats. Drawing on the strategies outlined in the Circular Electronic Roadmap, the study identified four main pathways relevant to design and development, procurement, and business model. The study, being exploratory and qualitative in nature, conducted semi-structured interviews with six PCB companies in Sweden. The results show that the concept of sustainability is dynamic, factors such as business nature, company size, market competitiveness, regulations, stakeholder’s expectations and priorities, and emerging frameworks are influencing the degree to which these practices are integrated into the companies. Numerous strengths include utilizing Life Cycle Analysis (LCA), adopting circular business model, sustainable technology innovation, and prioritizing environmental sustainability as an impact. Two main weaknesses are customers restriction and constrain in PCB design and upfront resource investment. Collaboration, local and regional innovation, active role of business association, and prospects for secondary market materials are discovered to serve as opportunities to advance the circular transition for companies Threats to sustainability practices include a lack of customer demand or interest, limited material information and traceability, and technical complexity of PCB. Overall, these findings could provide practical guidance for PCB companies and other stakeholders to support decision-making and actions to improve sustainability practices in the industry. / Miljöutmaningar relaterade till elektronisk- och elektrisk utrustningsindustri får företag att överväga en ny hållbarhetsmodell för att frikoppla ekonomisk tillväxt från resursförbrukning och avfallsgenerering. En betydande mängd litteratur fokuserar på material och processinnovation för tillverkningen av kretskort (eng. PCB), samtidigt som begränsad uppmärksamhet har ägnats åt industripraxis och strategier för cirkulär ekonomi. Den här studien syftar till att bidra med insikter om hållbar cirkulär ekonomi inom PCB-industrin. Den undersöker den nuvarande integrationen av hållbarhets- och cirkularitetsprinciper i PCB-företag i Sverige och bedömer associerade styrkor, svagheter, möjligheter och hot. Utifrån de strategier som beskrivs i färdplanen för cirkulär elektronik (eng. Circular Electronics Roadmap) identifierade studien fyra huvudområden som är relevanta för design och utveckling, upphandling och affärsmodell. I studien, som är explorativ och kvalitativ till sin karaktär, genomfördes semistrukturerade intervjuer med sex PCB-företag i Sverige. Resultaten visar att hållbarhetsbegreppet är dynamiskt, och att faktorer som typ av verksamhet, företagets storlek, marknadskonkurrens, regleringar, intressenternas förväntningar och prioriteringar, samt framväxande ramverk påverkar i vilken utsträckning dessa metoder integreras i företagen. Styrkor inkluderar användning av livscykelanalys (LCA), att anamma cirkulära affärsmodeller, hållbar teknikinnovation och prioritering av miljömässig hållbarhet. Två huvudsakliga svagheter är kundernas restriktioner i PCB-design samt resursinvesteringar i början av processen. Samarbete, lokal och regional innovation, aktiv roll för industriorganisationer och framtidsutsikter för återanvändning av material på den sekundära marknaden har upptäckts som möjligheter att främja den cirkulära övergången för företag. Hot inkluderar bristande efterfrågan eller intresse från kunderna, begränsad information och spårbarhet av material, samt PCB:s tekniska komplexitet. Sammantaget kan dessa resultat ge praktiska riktlinjer för PCB-företag och andra intressenter för att vägleda beslutsfattande och åtgärder för att förbättra hållbarhetsarbetet i industrin.

Additively manufactured fuels are becoming more common in the area of hybrid rockets due to the enhanced possibilities provided by computer aided design and improved additive material technology. When integrated with a highly compliant yet energetic paraffin wax, the additive manufactured material can help support the paraffin wax during the burn, and improve overall performance. This study investigates thin-walled acrylonitrile butadiene styrene structures that separate paraffin wax into azimuthally partitioned cells. The fuel grains are tested using a vertical test stand, custom nitrous system, and data acquisition system. The computer program Chemical Equilibrium with Applications is used to compare common hybrid fuels such as sorbitol, polybutadiene acrylic acid acrylonitrile, and poly(methyl methacrylate) along with the manufactured fuel. The experimental results indicate the promise of higher performance using paraffin. The analyses, however, show that refinements in grain design are necessary to fully realize the advantages of paraffin.

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Additive manufacturing technologies, including inkjet printing, have significantly transformed both research and industry, offering cost-effective and accessible solutions with innovative equipment capabilities. This study focuses on advancing p-type depletion and enhancement-mode poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) through molecular de-doping and rheological measurements, achieving a printing resolution of 30 μm. The versatility of these inks is demonstrated from three distinct perspectives. Firstly, the electrochemical stability of the enhancement-mode behavior opens new possibilities for low-power consumption, stable and sensitive platforms useful for detection of DopamineC and Ascorbic Acid at various concentrations. Secondly, we exemplify the democratization of in-house fabrication through fully printed, all-PEDOT:PSS, transparent, flexible, and bendable paper-based Organic Electrochemical Transistors (OECTs). This showcases the feasibility of employing inkjet printing to create functional electronic devices with ease. Lastly, we explore optimizations that enable deeper personalization by employing multiple material localizations and adjusting the electrical conductivity of OECTs. This engineering approach has resulted in the design of Organic Electrochemical Complementary Amplifiers (OECAs), we incorporated a second formulated enhancement-mode conducting polymer poly(benzimidazobenzophenanthroline) (BBL) as the n-type material to complement the PEDOT:PSS de-doped ink. These developments aim to foster global innovation, representing a significant leap forward in the field of organic electronics and in-house fabrication by complementing this engineering improvement from both fabrication and electrochemistry approaches.

Through qualitative interviews and secondary research, the emotional and ecological layers to a forest have been explored. Several studies and sources of data speak against Swedish forestry being sustainable, and the industry often views the forest through anthropocentric ethics with focus on economic value. The aim is to inform and inspire small-scale private forest owners in their decision making in forestry to consider more environmentally sustainable cultivation methods. There is a gap in communication between facts on forestry and small-scale private forest owners which the project aims to fill. The project looks at the forest holistically, through biocentric ethics and the Swedish folk art Kurbits, and covers ecological and cultural sustainability. This takes the shape of a booklet which uncovers a forest’s layers in both text and visuals.

The development of 5G and 6G entails new demandson antennas. This includes fast and reliable connections to a largenumber of devices. A wider area of coverage, and thus moreantennas are also expected, which is problematic for the expensiveantennas used today. To meet those demands, a geodesic lensantenna has been proposed. The antenna utilises several feedingports for beam forming. It is designed to operate at a frequencyof 8 to 12 GHz and is optimised to have an even coverage in thefar-field. The design is modulated with one fold to reduce theheight of the antenna. A prototype of the antenna is 3D printedwith PLA and coated with aluminium tape. The design has asimulated realised gain of 13.5 dBi and beam width of around30°. The 3D printed antenna could not be tested due to technicalproblems with the testing facilities, but is expected to have similarresults. / Med utvecklingen av 5G och 6G kommer stora krav på antenner. Flera enheter skall kunna vara uppkopplade och samtidigt krävs högre hastigheter med stabil uppkoppling. Utöver det ställs det även krav på en bred täckning vilket innebär att fler antenner behöver kopplas upp, vilka har höga kostnader idag. För att möta dessa krav har en design för en geodetisk linsantenn lagts fram. Antennen använder flera ingångar för att skapa en riktbar stråle. Den är designad för att operera inom frekvenserna 8 till 12 GHz och är optimerad för att få en jämn täckning i fjärrfältet. Designen nyttjar en vikning för att minska antennens höjd. En prototyp av antennen tillverkas med hjälp av 3D printad plast som beläggs med aluminiumtejp. Designen har en simulerad förstärking av 13.5 dBi och en strålbredd runt 30°. Den 3D printade antennen kunde inte testas på grund av tekniska problem med testutrustningen men förväntas ha liknande resultat som den simulerade. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to validate previous assumptions. Stereological relative density measurements showed that the as-printed material exhibited relative density in excess of 99%. Optical dimensional analysis found that the as-printed tensile specimens met ASTM E8 dimensional requirements in 14 out of 15 parts inspected. Baseline tensile tests indicated that the yield stress of the as-printed material is 24% higher than a cold-rolled alternative, while still achieving comparable ductility. The location of a tensile specimen on the build plate during the print was not found to have a significant effect on its mechanical properties. Theoretical behavior of notched tensile specimens based on finite element models matched experimental behavior in the actual specimens. Unique fracture behavior was found in both the unnotched reference and the most severe notch after microscopic inspection, and a root cause was proposed. Finally, extrapolating from previous studies and observing that experimental results matched theoretical models, it was determined that features inherent to SLM parts were not detrimental to the static performance of the as-printed material.

This work is an analysis of solutions to problems derived from inherent timing and signal integrity issues in the use and application of the IEEE 1149.1 Standard at the board level in conjunction with its test system. Setup or hold times violations may occur in a boundary scan chain using IEEE 1149.1 compliant devices. A practical study of the TDI-TDO scan data path has been conducted to show where problems may arise in relationship to a particular board topology and test system. This work points to differences between passing and failing scan path tests for problem characterization. Serial data flow is then analyzed and suitability is discussed. Within certain conditions, a solution is proposed. This work has been shown to work on the test system. Recommendations are made based on this experimental approach.