Idag är den traditionella tillverkningsprocessen för benproteshylsor som främst begränsar amputerade individer i olika länder från protesförsörjning på grund av att processen är både tidskrävande och kostsam för att producera högkvalitativa och anpassade proteshylsor. Syftetmed arbetet är att studera möjligheterna att använda 3D-skanning och additiv tillverkning (3Dprinting) för att skapa benproteshylsor med hjälp av dessa 3D-tekniker. Studien fokuserar på skanningsnoggrannhet och effektivitet samt två olika svarvariabler (ytjämnheten och maximalabelastningen) för 3D-printade benproteshylsor, där två olika processparametrar (lagerhöjd och infilltäthet) testas på två olika nivåer med en centrumpunkt genom att driva printingsprocessen systematiskt med hjälp av experimentell design (22-faktoriell design). Hårdvarorna Artec Eva, Artec Space Spider och Prusa MK4 användes för att utföra skanningsprocessen och printingsprocessen. Ett Polylacitic Acid-filament användes under printingsprocessen.Svarvariablerna togs fram med hjälp av två olika metoder (kompressionstest och ytjämnhetsmätning) som sedan analyserades för att visa variationen och undersöka hur processparametrarna kan påverka ytjämnhet (Artimetisk medelhöjd) och maximal belastninghos den 3D-printade proteshylsan. Artec Eva var snabbare och effektivare och kunde fånga upp 1990 bilder per sekund på cirka 164 sekunder. Testresultaten och analysen av svarvariablerna och processparametrarna visar att en ökning/minskning av lagerhöjden kan påverka ytjämnheten, samt att en ökning/minskning av infilltätheten kan påverka maxlasten.

Background: Manufacturing sectors are focusing on developing new manufacturing strategies and improving technologies since there has been a decrease in productivity in recent times. This has led to a massive growth in AM but also due to the benefits of implementing AM technologies. However, there are some challenges to overcome with AM implementation.  Purpose: The purpose of this study is to explore the AM implementation to achieve sustainability in manufacturing companies.   Research questions:  ·      What are the challenges in achieving sustainability with AM implementation for manufacturing companies? ·      How can manufacturing companies achieve environmental and economic sustainability with AM implementation through an industrial technology center?  Method: This study is based on a qualitative method with an abductive approach. The theoretical framework has been gathered through a literature review and the empirical data is based on interviews at the case company. The analysis is based on a thematic analysis method.  Conclusion: This thesis concluded that challenges in achieving sustainability with AM implementation are related to inaccuracies of produced parts and components and geometric complications. This was based on design complexities and printer capabilities. The other conclusion made was that there are aspects that contribute to environmental and economic sustainability through AM implementation such as enhancing process efficiency and low setup costs.

Metal additive manufacturing is an important tool for the creation of cost effective and environmentally friendly components for the future of the aerospace industry. Newly developed methods such as Direct Energy Deposition, Laser Beam Wire (DEDLB/w) have the potential to quickly and effciently manufacture aircraft engine components of high quality when utilising the correct set of process parameters. Establishing these parameters is a challenging task as product defects can be diffcult to detect and localise during the DEDLB/w process. This thesis explores the possibility of detecting crack type defects during the additive manufacturing of Nickel-Based Superalloy components using in process acoustic emission inspection and hierarchical clustering to evaluate DEDLB/w process parameter sets. After observing numerous material depositions made using DEDLB/w, crack-like signals were observed and clustered using features derived from Acoustic Emission (AE) data. The results were then evaluated and validated using X-Ray and X-Ray Computed Tomography (µCT) inspection. Crack-like acoustic emissions were recorded from depositions in which cracks were later found using X-rayand µCT inspection, and these emissions were successfully clustered over multiple depositions using statistical analysis and agglomerative clustering.

Yes / Three dimensional printing (3DP) was used to engineer novel oral drug delivery devices, with specialised design configurations loaded with multiple actives, with applications in personalised medicine. A filament extruder was used to obtain drug-loaded - paracetamol (acetaminophen) or caffeine - filaments of polyvinyl alcohol with characteristics suitable for use in fused-deposition modelling 3D printing. A multi-nozzle 3D printer enabled fabrication of capsule-shaped solid devices, containing paracetamol and caffeine, with different internal structures. The design configurations included a multilayer device, with each layer containing drug, whose identity was different from the drug in the adjacent layers; and a two-compartment device comprising a caplet embedded within a larger caplet (DuoCaplet), with each compartment containing a different drug. Raman spectroscopy was used to collect 2-dimensional hyper spectral arrays across the entire surface of the devices. Processing of the arrays using direct classical least squares component matching to produce false colour representations of distribution of the drugs showed clearly the areas that contain paracetamol and caffeine, and that there is a definitive separation between the drug layers. Drug release tests in biorelevant media showed unique drug release profiles dependent on the macrostructure of the devices. In the case of the multilayer devices, release of both drugs was simultaneous and independent of drug solubility. With the DuoCaplet design it was possible to engineer either rapid drug release or delayed release by selecting the site of incorporation of the drug in the device, and the lag-time for release from the internal compartment was dependent on the characteristics of the external layer. The study confirms the potential of 3D printing to fabricate multiple-drug containing devices with specialized design configurations and unique drug release characteristics, which would not otherwise be possible using conventional manufacturing methods. / The full-text of this article will be released for public view at the end of the publisher embargo on 10 Oct 2016.

Yes / Three-dimensional printing (3DP) has demonstrated great potential for multi-material fabrication because of its capability for printing bespoke and spatially separated material conformations. Such a concept could revolutionise the pharmaceutical industry, enabling the production of personalised, multi-layered drug products on demand. Here, we developed a novel stereolithographic (SLA) 3D printing method that, for the first time, can be used to fabricate multi-layer constructs (polypills) with variable drug content and/or shape. Using this technique, six drugs, including paracetamol, cffeine, naproxen, chloramphenicol, prednisolone and aspirin, were printed with dfferent geometries and material compositions. Drug distribution was visualised using Raman microscopy, which showed that whilst separate layers were successfully printed, several of the drugs diffused across the layers depending on their amorphous or crystalline phase. The printed constructs demonstrated excellent physical properties and the different material inclusions enabled distinct drug release profiles of the six actives within dissolution tests. For the first time, this paper demonstrates the feasibility of SLA printing as an innovative platform for multi-drug therapy production, facilitating a new era of personalised polypills.

Denna rapport detaljerar ett examensarbete där användbarheten på en lokalt skapad 3D-skrivare förbättrats i syfte av att tillåta skrivarens användning av studenter på KTH Södertälje. Skrivarens har ursprungligen byggts för att agera som ett pågående projekt som kan återupptas som examensarbete, varav detta är det tredje. Skrivaren i fråga är en FFF-skrivare i ”box” stil med utskriftsvolymen 400 x 400 x 375 mm. Vid projektstart är skrivaren i nominellt användbart skick men saknar dokumentation, processrutiner och användbara slicerprofiler. Skrivaren besitter även hårdvaran för att tillåta utskrifter med två material men denna funktion har aldrig implementerats. Framtagningen av slicerprofiler har tagit upp majoriteten av arbetet och har utförts genom iterativ testning där inställningar modifieras och testas, vartefter positiva ändringar implementeras för att gradvis eliminera defekter och minska haveririsk. Projektet har levererat en full slicerprofil som tillåter pålitliga utskrifter med två olika PLA-filament samt en användarmanual till skrivaren. Utöver användarverktygen så detaljeras även de reparationsarbeten och hårdvaruändringar som gjorts. Profil, manual, rådata och filer för utskrivna komponenter är tillgängliga i en projektmapp som kan hittas från en länk i början av kapitel 4. / This report details a thesis project for getting a 3D-printer internally built at KTH Södertälje into a state where it can be used by other students for unrelated projects. The printer acts as an ongoing project that can be used for thesis work, with this project in particular being the third in line. The printer in question is an FFF-printer with the ”box” configuration and a print volume of 400 x 400 x 375 mm. At project start, the printer is nominally in working condition but lacks any documentation for proper handling and slicer settings. Additionally, its multi-material function has never been successfully implemented. Adjustment of slicer settings is done using iterative testing, wherein settings are modified and tested, with positive changes being integrated and negative changes discarded with the intent of removing defects and minimizing risk of print failure. The project has delivered a slicer profile for Cura capable of reliably printing with two different PLA filaments as well as a user manual. Hardware upgrades and repair work has also been detailed. The profile, user manual, raw data and object files for upgrades and spares can be found through a link in the beginning of chapter 4.

[pt] A manufatura avançada, mais especificamente a manufatura aditiva, tem sido explorada cada vez mais, desde o surgimento da chamada Indústria 4.0. As técnicas de impressão 3D, incluindo a grande diversidade de tecnologias e de materiais que podem ser utilizados, permitem uma grande gama de aplicações. Com o intuito de explorar mais e aprofundar os estudos ligados a este tema, esta pesquisa investigou as propriedades mecânicas do aço inoxidável PH1, fabricado numa impressora EOS M280 através do processo de sinterização de camadas por laser. Buscou-se explorar as características do material, identificando influências da forma de fabricação e comparando as suas propriedades medidas, com as que são informadas pelo fabricante da impressora e com materiais laminados similares encontrados no mercado. Os ensaios de tração, rugosidade, dureza, impacto, M.E.V. e fadiga foram selecionados considerando a obtenção das propriedades mais relevantes do material para a indústria das peças produzidas pela tecnologia. Os resultados medidos foram comparados com os obtidos pela manufatura tradicional, para que fosse possível analisar a viabilidade e confiabilidade de substituição do método de fabricação. Estes indicam que o material impresso é resistente e pode substituir peças obtidas pela manufatura tradicional, mas deve ser utilizado com algumas considerações pois este sofre grande influência da orientação de impressão. Adicionalmente, foi desenvolvido um roteiro de fabricação digital de peças de reposição, para permitir a fabricação de peças que, juntamente com os ensaios mecânicos realizados, permite a avaliação do caminho a ser seguido dentro da manufatura aditiva para cada peça. / [en] Advanced manufacturing, more specifically additive manufacturing, has been increasingly explored since the emergence of the so-called Industry 4.0. 3D printing techniques, including the great diversity of technologies and materials that can be used, allow a wide range of applications. In order to further explore and deepen the studies related to this topic, this research investigated the mechanical properties of PH1 stainless steel, manufactured in an EOS M280 printer through the laser layer sintering process. The characteristics of the material were explored, identifying influences of the form of manufacture and comparing its measured properties with those reported by the printer manufacturer and with similar laminated materials found on the market. The tensile, roughness, hardness, impact, M.E.V. and fatigue tests were selected considering obtaining the most relevant properties of the material for the industry of the parts produced by the technology. The measured results were compared with those obtained by traditional manufacturing, so that it was possible to analyze the feasibility and reliability of replacing the manufacturing method. These indicate that the printed material is resistant and can replace parts obtained by traditional manufacturing, but it must be used with some considerations as it is greatly influenced by the printing orientation. Additionally, a script for the digital manufacturing of spare parts was developed, to allow the manufacture of parts that, together with the mechanical tests performed, allows the evaluation of the path to be followed within the additive manufacturing for each part.

This thesis performs closed-loop control of a 3D printed soft bending actuator with feedback from a 3D printed strain sensor. This process utilizes the Finite Element Method (FEM) to design a bellow type pneumatic bending actuator that can handle pressures up to 4 bar. The developed actuator is produced with a Fused Deposition Modeling (FDM) 3D printer method with the elastic filament NinjaFlex. Soft sensors are 3D printed with the conductive filament Eel and their strain-resistive performance in hysteresis, linearity, and repeatability are investigated by testing 3D printed sensors with different shapes. The optimal sensor design is then selected and applied onto the soft actuator and the resistance signal from the sensor is used as the shape feedback signal for the soft actuator. Two different controllers are applied for the shape control of the soft actuator using the feedback from the sensor and the controller performance is compared experimentally. A gripper composed of three closed-loop controlled soft actuators is developed to perform complex grasping tasks. / Denna avhandling konstruerar ett 3D-skrivet mjukt ställdon som återkopplas med en 3D-skriven böjsensor. Arbetet använder Finita Elementmetoden (FEM) för att skapa ett böjande bälgställdon som klarar av 4 bar av lufttryck. Det framtagna ställdonet är tillverkad av det elastiska filamentet NinjaFlex med 3D-skrivarmetoden Smält Deponeringsmodellering (FDM). Dem mjuka sensorerna är 3D-skrivna med det elektriskt ledande filamentet Eel. Sensorernas ansträgning-resistiva prestanda med avseende på hysteres, linjäritet, och repeterbarhet är undersökta genom att utföra experiment med olika former. Den optimala sensorformen är sedan applicerad på det mjuka ställdonet och dess resistiva signal från sensorn används för återkoppling av det mjuka ställdonets böjning. Med den applicerade sensorn utvärderas två olika kontrollmetoder för att kontrollera böjningen av det mjuka ställdonet, kontrollmetodernas prestanda jämförs sedan experimentellt. Ett gripdon som består av tre återkopplade, mjukaställdon är sedan konstruerad för att utföra komplexa grepp.

This thesis investigates additive manufacturing as an alternative method for producing casting patterns in sand casting processes. Traditionally, casting patterns are manufactured using CNC milling, which entails long lead times, high manufacturing costs, and negative environmental impacts. Surface finish plays a significant role in casting pattern production and is one of several critical factors in assessing a method's suitability. By examining additive manufacturing, its potential and suitability for casting pattern production can be evaluated. A key aspect of the study is the examination conducted to assess the surface finish of radius and draft angles on casting patterns fabricated through FDM and SLS printing. Surface finish was evaluated by measuring the Sa value using a digital microscope. Achieving high-quality surfaces on casting patterns is crucial for ensuring smooth and uniform sand mold patterns. The investigation resulted in moderately rough surfaces on the radius and draft angles of the casting patterns, with the Sa value varying depending on the casting pattern's layer thickness, angle, and radius. The conclusion of this study is that FDM technology holds potential for casting pattern production but may require optimization to overcome existing challenges. Introducing 3D printing into foundries could lead to a more efficient and sustainable production process while reducing manufacturing costs for casting patterns.

<p dir="ltr">Maxillofacial and oral defects originate from congenital conditions such as cleft palate, diseases such as osteosarcoma that cause malignancies, and from injuries due to blasts or vehicular accidents. These defects lead to complications for the patient, including challenges with speech, infections, as well as damaging psychological effects owing to the patient’s distorted physical appearance. The current standard of care uses particulates of freeze-dried auto- or allografts covered by a titanium mesh secured in place by screws. This approach is limited by: 1) variability; 2) the length of time the patient is exposed to potential infection during surgery; and 3) overpacking, often leading to diminished bone regeneration as blood vessels may fail to form. Prior research has demonstrated the benefits of using 3D printed titanium covers to protect the core particulate. Benefits such as reduction in surgical times, more reproducible than an in vitro human design, and patient specific. However, these covers do lead to an increased degree of stress shielding, since 3D printed titanium covers are thicker than the current titanium meshes on the market. Additionally, this does not address the issues that can occur with an overpacked core. To address these fallbacks, we designed a 3D printable, biodegradable, and implantable device with patient-specific shape and a porous core-cover structure. We hypothesized that a 3D printed porous cover-core bone graft, with controlled porosities, would enhance infiltration and osteointegration. By using finite element analysis and in vitro modeling, we fine-tuned the design to withstand possible masticatory forces while designing the hydrogel to maximize cell viability. First, we optimized the FEA model and demonstrated the feasibility of 3D printing the cover and core design. Our results demonstrated that a polycaprolactone (PCL) cover with 1 mm pores, secured with buccal screws, minimized stress shielding while providing stresses within a range that would promote osteogenesis. Additionally, we developed a hybrid core composed of methacrylated alginate, methacrylated gelatin (AlgGelMa), and tricalcium phosphate (TCP), which provided elastic properties within the range of the FEA model, promoted cell infiltration, supported growth factor sequestration and demonstrated osteogenesis through RT-PCR. Overall, we demonstrated the feasibility of a patient-specific resorbable osteoprotective cover with a hydrogel core that facilitates stress propagation and improves bone healing outcomes.</p>