Additive manufacturing is a growing field dominated by printing processes that soften and re-solidify material, depositing this material layer by layer to form the printed shape. Increasingly, researchers are pursuing new materials to enable fabrication of a wider variety of associated capabilities. This includes fabrication with high-viscosity materials of many new classes of material compositions, such as doping for magnetic or electrically conducting polymers. These additives complicate the materials deposition process by requiring complex, non-linear calibration to synchronize these new candidate materials with the additive manufacturing software and hardware. In essence, additive manufacturing is highly dependent on identifying the delicate balance between materials properties, hardware, and software-which is currently realized via a time-consuming and costly iterative calibration process. This thesis is concerned with reducing this cost of calibration, in particular by providing a time-based metric based on material viscosity for material retraction at the conclusion of each extrusion. It presents a novel non-contact method of determining the material retraction rate (during reversal of extrusion), by measuring the variation in laser intensity resulting from the deformation of the material reservoir due to change in material pressure. Commercially available laser measurement systems cost more than $20,000 and are limited to 1 μm at a 300 ms (3 Hz) sampling rate. The experimental setup presented in this thesis costs less than $100 and is capable of taking measurements of 1 - 2 μm at a 0.535 ms (1870 Hz) sampling rate. For comparison, the stepper motor driving the material extruder operates at 0.667 ms (1500 Hz). Using this experimental setup, an inverse correlation is shown to exist between the viscosity of a material and the rate at which the material is retracted. Using this correlation and a simplified material analysis process, one can approximate the retraction time necessary to calibrate new materials, thereby significantly improving initial estimated calibration settings, and thus reducing the number of calibration iterations required to ready a new material for additive manufacturing. In addition, the insight provided into the material response can also be used as the basis for future research into minimizing the calibration process. / Master of Science / Additive manufacturing is a growing field with an ever-expanding base of materials used in the printing process. Two types of material gaining popularity in the commercial and academic communities are pastes and liquids. These materials require a different method of printing, and users need to take into account other considerations, such as viscosity and pressure, for their precise control. Traditionally, a new material would require a time consuming or costly calibration process to properly print. To decrease the investment required for calibration, this thesis presents a new non-contact method of measuring the pressure of the liquids using a laser to detect a dimensional change in the size of the container. This measurement technique enables an initial calibration estimate that is closer to the optimal setting, potentially allowing for better printing results when working with new materials for additive manufacturing.

OBJECTIVES: This study aims to determine the accuracy of 3D printed models after different storage conditions using two different material/printer systems. METHODS: A STL file of a full-arch maxillary cast was used to print 30 models from two different technologies, Carbon 3D and Formlabs 3 printers. The models were printed at 50 micrometers layer thickness. These printed models were randomized into 3 groups per printer (n=5) for storage: Room-temperature (22 ± 2 °C), low-temperature (~4 ± 1 °C), and High-temperature (50 ± 2 °C). Each of the models was scanned at a designated storage time to generate STL files, which were imported into a 3D inspection software for superimposition and evaluation of deviations using 3D comparison, points of reference, and inter-tooth distances. The trueness in this project was the absolute tooth distance difference between the reference and the testing scan. Precision in this project was the standard deviation of the tooth distances among the measurement of duplicate models within each subgroup. A regression model was used to compare the differences among the groups. RESULTS: The trueness and precision of the printed models were found significantly affected by the two printer types and different storage temperatures. Dimension changes were found to be more on the gingiva and the tooth surface of the molar area. Models under high temperatures showed expansion, while models under low temperatures presented shrinkage. Models under room temperature did not show significant distortions in general. Carbon 3D printed models showed higher in-tolerance percentages compared to Formlabs 3. CONCLUSIONS: Different printer types and storage conditions significantly affect the dimension accuracy of 3D printed dental models. Carbon 3D printed models showed less deviation compared with Formlabs 3 in terms of trueness and precision. Storage of 3D printed models at higher temperatures should be avoided to prevent dimension distortion. Lower temperature storage for the Carbon model is recommended.

Yes / This paper presents an improved mathematical model for calculation of distortion vectors of two aligned surface meshes. The model shows better accuracy when benchmarked to an existing model with exceptional mathematical conditions, such as sharp corners and small radii. The model was implemented into a developed distortion compensation digital tool and applied to an industrial component. The component was made of Inconel 718 and produced by laser powder bed fusion 3D printing technology. The digital tool was utilised to compensate the original design geometry by pre-distortion of its original geometry using the developed mathematical model. The distortion of an industrial component was reduced from approximately ±400 µm to ±100 µm for a challenging thin structure subjected to buckling during the build process.

Recently, 3D printing has received increasing attention for the fabrication and assembly of electrodes for batteries due to the freedom of creating structures in any shape or size, porosity, flexibility, stretchability, and chemistry. Particularly, zinc ion batteries (ZIBs) are favored due to high safety, cheap materials cost, and high volumetric capacity (5,849 mAh/cm3), however, rapid evaporation of Zn due to low melting temperature has limited its 3D printability via conventional laser-based additive manufacturing technique. Here, we develop a printable ink for the fabrication of flexible and 3D printed Zn anode with varied surface areas using the direct ink writing (DIW) method. Our 3D printed porous and high surface area Zn anode structures effectively suppressed the dendrite growth while providing high Zn ion diffusion towards the cathode to significantly enhance the performance of ZIB. By varying filament distancing and path, we 3D printed zinc anode structures with different active surface areas, surface area to volume ratio, porosity, flexible and multiple layer structures that can be incorporated on any device. Carbon in the composite improved conductivity, and mechanical stability of 3D printed zinc anode. Our 3D printed composite anodes allowed flexible designing of batteries surpassing conventional battery designs such as coin cells or pouch cells and can be used to design printed energy storage systems.

3D-skrivare har många användningsområden och de har blivit vanliga i många industrier.Idag talas det om att denna teknik kan vara en möjlig väg till mer hållbart byggande.Tekniken anses lovande inom byggproduktion bland annat för att det visat sig att den kanreducera materialspillet och ge kortare byggtider. Till viss del används tekniken redan förbyggnadstillverkning, men då främst med betong.Målet med arbetet är att beskriva nuvarande kunskap rörande 3D-printing medträbaserad massa, samt att undersöka möjligheten till att använda en träbaserad massabestående av sågspån, vatten och lignin vid 3D-printing.För att kunna nå målet användes en kombination av litteratursökning och laborativaexperiment. Litteratursökningen användes både för att undersöka tidigare genomförda studiergällande träbaserade material i samband med 3D-printing, samt som inspiration för deingredienser och proportioner som används i de laborativa experimenten.Enbart studier om träbaserad 3D-printing studerades. De testobjekt som togs fram i delaborativa experimenten utvärderades i hållfasthet, dimensionsstabilitet och vidhäftning.Resultaten av det laborativa arbetet tyder på att det framtagna materialet går att extrudera,men att det har låg draghållfasthet. Lagren bands samman bra för samtliga tester, medantryckhållfastheten gav varierande resultat. Högst tryckhållfasthet gavs av den blandning somhade högst andel lignin, samt torkades under längst tid.Slutsatsen är att materialet kan vara till nytta, men att rätt användningsområde börbestämmas, då materialet inte tål alltför stora laster. / 3D printers have many uses and they have become common in many industries. Today, thistechnology is seen as a possible route to more sustainable construction. The technology isconsidered promising in construction engineering, among other things because it has beenshown that it can reduce material waste and provide shorter production times. To someextent, the technology is already being used for building construction, but then mainly withconcrete.The aim of this study is to describe current knowledge regarding 3D printing with woodbasedpulp and to investigate the possibility of using a wood-based pulp consisting ofsawdust, water and lignin for 3D printing.In order to reach the goal, a combination of literature search and laboratory experiments wasused. The literature search was used both to investigate previously conducted studiesregarding wood-pulp based materials in 3D printing and as inspiration for the ingredients andproportions used in the laboratory experiments.Only studies on wood-based 3D printing were studied. The test objects produced in thelaboratory experiments were evaluated in strength, dimensional stability and adhesion. Theresults of the laboratory work indicate that the produced material can be extruded, but that ithas low tensile strength. The layers bonded well for all tests, while the compressive strengthresults varied. The highest compressive strength was given by the mixture with the highestproportion of lignin and the longest drying time.The conclusion is that the material might be useful, but that the correct area of use should bedetermined, as the material cannot withstand excessive loads.Keywords:

FDM 3D printing is an additive manufacturing technology that is widely used, mainly for rapid prototyping. It is also one of the cheapest and most accessible AM technologies for consumers. FDM printers, and especially cheaper alternatives, can have problems with creating high quality prints. Reasons include poor design, inaccurate construction, cheap components, and improper tuning. Input shaping is a control technique that may help mitigate defects caused by poor mechanical design or construction. The “ringing” defect may be eliminated by applying this solution. To perform an evaluation in sub-optimal mechanical conditions a 3D printer was constructed with a cantilever design mainly using plastic prints for mechanically important parts. Printing tests were done with and without input shaping. The results that were produced showed a direct effect of input shaping in 3d printers. / FDM 3D-printing är en additiv tillverkningsteknik som är mycket använd, främst för snabb prototypering. Det är också en av de billigaste och mest tillgängliga AM-teknikerna för konsumenter. FDM skrivare, och särskilt billigare alternativ, kan ha problem med att skapa högkvalitativa utskrifter. Orsaker inkluderar dålig design, konstruktionfel, billiga komponenter och felaktig justering. Input shaping är en kontrollteknik som kan hjälpa till att mildra defekter som orsakas av dålig mekanisk design eller konstruktion. "Ringning" defekten kan elimineras genom att tillämpa denna lösning. För att utföra en utvärdering i dåliga mekaniska förhållanden konstruerades en 3D-skrivare med en fribärande design som använder plastutskrifter för mekaniskt viktiga delar. Utskriftstester gjordes med och utan input shaping. Resultaten som framställdes visade på en uppenbar förbättring av print kvalité som en direkt effekt av input shaping.

Saab Surveillance in Järfä̈lla constructs complex products, such as radars and electronic support measures. Saab sees an advantage in manufacturing details with additive manufacturing as it enables a high level of complexity. Additive manufacturing is relatively new in the industry and consequently there are uncertainties regarding the process. The purpose of this bachelor thesis was to improve the knowledge of the repeatability of additive manufactured parts as well as compare additive manufactured test rods in two different directions, horizontally and vertically, to subtractive manufactured test rods with a vibration test. The vibration test was conducted to simulate the operative environment where the additive manufactured parts might be implemented in the future. Before the vibration test could be performed, the test rods were designed in a 3D-modeling program and analysed with a finite element method to achieve the required natural frequency range of 100 - 200 Hz and a maximal bending stress of 60 - 80 MPa in the notched area of the test rod. It was concluded that the subtractive manufactured test rods had the highest repeatability. The horizontally additive manufactured test rods had a higher repeatability than the vertically additive manufactured test rods, but the vertically additive manufactured test rods had the highest overall strength. It was also concluded that more studies are needed to ensure that additive manufactured parts can be produced with high repeatability while maintaining the structural integrity. / Saab Surveillance i Järfä̈lla konstruerar komplexa försvarsprodukter som till exempel radarsystem. Additiv tillverkning i metall möjliggör tillverkning av produkter med hög komplexitet, men då tillverkningsprocessen är relativt ny i industrin finns det en stor osäkerhet kring processen. Syftet med detta kandidatexamensarbete var att få en bättre förståelse för repeterbarheten hos additivt tillverkade delar samt att jämföra additivt tillverkade provstavar konstruerade i två olika riktningar, horisontellt och vertikalt, med svarvade provstavar med hjälp av ett vibrationstest. Vibrationstestet genomfördes för att simulera den operativa miljön där de additivt tillverkade detaljerna skulle kunna implementeras i framtiden. Innan vibrationstestet kunde utföras simulerades provstavarnas design i en mjukvara för 3D-modellering. En finit element-analys utfördes även fö̈r att få en egenfrekvens inom intervallet 100 - 200 Hz och en maximal böjspänning mellan 60 - 80 MPa i anvisningen på provstaven. Slutsatsen drogs att de traditionellt bearbetade stavarna hade den högsta repeterbarheten. De horisontellt additivt tillverkade stavarna hade högre repeterbarhet än de vertikalt additivt tillverkade stavarna, men att de vertikalt additivt tillverkade stavarna hade ett längre utmattningsliv. Det kunde även konstateras att fler studier inom ämnet behövs för att kunna säkerställa repeterbarheten hos additivt tillverkade delar utan att behöva kompromissa med hållfastheten.

Modern research in prosthetic devices and other assistive technologies are constantly pushing boundaries. While the technology is impressive, it is still inaccessible for the greater part of the people in need of it. Advanced devices are often extremely expensive and require regularly maintenance from professionals. Enabling the Future is a global network of volunteers and was founded to face these problems. They design and 3D-print mechanical prosthetics for people in need all over the world. Most of the designs used by Enabling the Future are purely mechanical and do not implement motors. The purpose of this thesis was to take a new approach to the design and construction of low-cost motorized prosthetic hands. By distancing all the electronic components from the hand, including the motor, the project aimed to create a device compatible with all current designs of the Enabling the Future community. To conceptualize this approach a demonstrator was constructed and tested. It utilized a muscle sensor which allowed users to control the hand by tightening their muscles. The distance between the electronic components and the prosthetic hand measured approximately one and a half meters and still transfered enough force, from the motor to the hand, to deliver an adequate grip strength. / Modern forskning inom protestillverkning och andra handikapphjälpmedel gör kontinuerligt stora framsteg. Trots att tekniken är imponerade är den fortfarande otillgänglig för den största del människor som behöver den. Avancerade hjälpmedel är ofta extremt dyra och kräver kontinuerligt underhåll från yrkesverksamma. Enabling the Future, ett globalt nätverk av volontärer, grundades för att utmana dessa problem. De konstruerar och tillverkar 3D-skrivna mekaniska proteser för människor med behov över hela världen. De flesta konstruktioner som används av Enabling the Future är helt mekaniska och använder inga motorer. Syftet med detta kandidatexamensarbete var att med nya tillvägagångssätt konstruera en billig motoriserad handprotes. Genom att placera all elektronik på en distans från handen, inklusive motorn själv, var tanken att skapa ett system som är kompatibelt med de konstruktioner som Enabling the Future använder. För att förverkliga detta konstruerades en prototyp som testats. Prototypen använde sig av en muskelsensor som lät användaren kontrollera proteshanden genom att spänna sin arm. Distansen mellan de elektriska komponenterna och protesen var ungefär en och en halv meter, samtidigt som tillräckligt stor kraft kunde transporteras för att stänga handen med ett tillräckligt grepp.

The concept of a robotic manipulator is widely used throughout many industries. In this project, a manipulator of the type SCARA, selective compliance articulated robot arm, is constructed. The aim was to examine how such a robot could be constructed using 3D-printing and how accurate it would be. Other than 3D-printing, parts in the form of guiding rods, lead screw, bearings, pulleys and timing belts were used. Together with a microcontroller, the robot operates using three stepper motors. In the end it resulted in a SCARA with reasonable accuracy considering the methods used, more specifically the largest average error was 3.6cm in the X direction and 2.3 cm in the Y direction. The largest drawback of the final construction was the negative balance between tightening the belts and friction in the inner joint. Tightening the belts meant larger friction and thereby undesired movement properties. Doing the opposite meant that the belts could start slipping and enabled backlash. / Konceptet av en robotarm används brett inom många industrier. Detta projekt syftar till att konstruera en robot avtypen SCARA, selective compliance articulated robot arm. Målet var att undersöka hur en sådan robot kan 3D-printas och dess precision. Förutom 3D-printade delar användes även guidestänger, kullager, kamremmar och remskivor. Robotens rörelser styrs tillsammans med en mikrokontroller och tre stegmotorer. Med tillvägagångssätten i åtanke resulterade projektet in en SCARA med rimlig precision. Mer specifikt var medelfelet 3.6 cm i X-led och 2.3 cm i Y-led. Den största nackdelen med den slutgiltiga konstruktionenvar den negativa jämvikten mellan att spänna kamremmarna och friktionen i den inre armleden. Att spänna kamremmarna innebar en ökning i friktion och därmed oönskade rörelseegenskaper. Att göra tvärtom innebar att bältena löpte större risk att glida ur och möjliggjorde dödgång.

A key component of biological research is cell culture technology, which allows researchersto examine the behavior and functionality of cells in controlled environments. Conventionalcell culture monitoring frequently necessitates taking the cultures out of their incubators tomake observations under a microscope. This exposes them to pollutants and changes in thesurrounding environment and may jeopardize the integrity of the experiment.This thesis presents the development of a cost-effective, miniaturized microscope designedfor imaging of cell cultures directly within incubators. By integrating simple, inexpensiveglass lenses and 3D-printed components and focusing on the ESP32-CAM module for digitalimaging, the project explores various optical setups to optimize image quality while minimizingdisruption to cell environments.Central to the research was the identification and testing of diverse optical configurations todetermine the most effective arrangement for both brightfield and fluorescence microscopy.The design features a baseplate for stability, a filter plate for fluorescence imaging, and afocus adjustment mechanism using magnets. Iterative enhancements led to a side illuminationtechnique using an economical LED, removing the need for a beamsplitter and simplifying theoptical path.The final microscope demonstrated successful brightfield imaging and weak fluorescenceimaging of Madin-Darby Canine Kidney (MDCK) II cell cultures marked with Green FluorescentProtein (GFP), using a magnification ratio of 2.5:1 through an infinity-corrected optical system.The findings illustrate the potential of developing an economical, functional microscope thatcan be readily replicated and scaled for use in cell culture technology. / En central del av biologisk forsking är användningen av cellkulturer, vilket tillåter forskare attutforska beeendet och funktionerna av celler i kontrollerade miljöer. Konventionell bevakning avcellkulturer kräver ofta att de tas ut från deras inkubatorer för att observeras under ett mikroskop.Detta kan utsätta dem för föroreningar och förändringar i omgivningen vilket kan äventyra helaexperimentet.Det här examensarbetet beskriver utvecklingen av ett kostnadseffektivt, miniatyriserat mikroskopanpassat för att avbilda cellkulturer inuti inkubatorer. Genom att integrera enkla, billigaglaslinser och 3D-printade komponenter, samt ESP32-CAM modulen för bildtagning, utforskardetta arbete olika optiska system för att optimera bildkvalitet och minimera störningar i cellernasmiljö.En väsentlig del av forskningen involverade identifiering och testning av olika optiska konfigurationerför att bestämma det mest effektiva arrangemanget för både brightfield- och fluorescensmikroskopi.Designen inkluderar en basplatta för stabilitet, en filterplatta för fluorescensavbildning ochen fokusjustering som utnyttjar magneter. Iterativa förbättringar ledde till utvecklingen av enbelysningsteknik med en billig LED, vilket tog bort behovet av en stråldelare och förenkladeden optiska banan.Det slutgiltiga mikroskopet uppvisade framgångsrik avbildning med brightfield och begränsadavbildning med fluorescens av MDCK II cellkulturer märkta med GFP. En förstoringsfaktor2.5:1 användes genom ett oändlighetskorrigerat optiskt system. Resultaten demonstrerar potentialenav att utveckla ett ekonomiskt och funktionellt mikroskop som kan replikeras för användninginom cellkulturforskning.