Rapporten behandlar ett kandidatarbete i maskinteknik som utfördes tillsammans med Evomatic AB i Karlshamn. Syftet med detta examensarbete var att genom inlärda kunskaper under utbildningen utveckla och generera en lösning som möjliggör automatiskt utbyte av gripfingrar på ett gripdon som används i ett av Evomatics automatiserade robotsystem.  Genom en behovsanalys togs en kravspecifikation fram tillsammans med företaget som innehåller de krav och önskemål som företaget ställer på produkten. Kravspecifikationen beskriver specifikt och detaljerat de krav som ställs på produkten, i vårt fall var de främsta kraven att produkten skulle motstå ett visst vridmoment och hålla sig inom måtten för de anslutande delarna, huvudkravet var att produkten helt automatiserat utföra sin arbetsuppgift.  Efter att ha identifierat kundbehovet samt etablerat kravspecifikationen genomfördes en konceptgenerering där ett antal olika lösningskoncept togs fram genom brainstorming och brainwriting. De för- och nackdelar med respektive koncept ställdes mot varandra i en konceptsållningsmatris, för att tydliggöra slutsatsen om vilket koncept som var mest lämpligt och praktiskt genomförbart.  Det valda konceptet vidareutvecklades och tillverkades genom bl.a 3D-printing för att sedan genomgå ett funktionstest för att tydligt visa dess svagheter och styrkor i praktiken. Funktionstestet gav ett nära önskvärt resultat med bra respons från intressenten.  Slutsatsen som drogs utifrån det resultat som testet genererade var att konceptet i helhet fungerar som tänkt, med utrymme för förbättringar som uppmärksammades under testningstillfället. Dessa förbättringar implementerades i en slutlig version av konceptet för att möjliggöra framtagning av prisbild och jämförelse mot tidigare lösning. / This report represents a final degree project in mechanical engineering which was performed in cooperation with Evomatic AB, located in Karlshamn. The purpose of this thesis was to, through the knowledge learned during the education, develop and generate a solution that enables the automatic exchange of gripper fingers on a gripper unit used in one of Evomatic´s automated robot systems.  Through a needs analysis, a specification of requirements was generated together with the company, containing the requirements and wishes of the solution. This specification describes the requirements of the product in detail, in our case the main requirements were that the product should withstand a certain amount of torque, stay within the dimensions of the connecting components, but the main requirement was that the product would successfully perform its task automatically.  After having identified the customer need and established the specification of requirements, a concept development process was carried out where a number of different ideas were developed through brainstorming and brainwriting. The pros and cons with each concept were contrasted in a concept screening matrix, in order to clarify the conclusion of which concept was most suitable and practically feasible.  The chosen concept was further developed and manufactured through, among other things, 3D printing and then underwent a functional test to clearly show its weaknesses and strengths in practice. The functional test gave a close to desirable result with a good response from the company. Conclusively, the result generated by the test showed that the concept filled its function and purpose, with room for improvement, which was noted during the testing. These improvements were implemented in the final version of the concept as a 3D-model, to make it possible to produce a price point compared to the previous solution used.

Self-oscillating synthetic vocal fold (VF) models are often used to study human voice production. In this thesis, a method for fabricating multi-layer self-oscillating synthetic VF models using silicone 3D printing is presented. Multi-material 3D printing enables faster fabrication times with more complex geometries than traditional casting methods and builds a foundation for producing VF models with potentially more life-like geometries, materials, and vibratory characteristics. The printing method in this study used a custom dual extruder and slicing software to print UV-curable liquid silicone into a gel-like support matrix. The extruder was fabricated using high-torque stepper motors with high resolution leadscrews for precise extrusion and retraction. The custom slicing software accounted for challenges with printing a low-viscosity uncured silicone and was capable of allowing the user to visually observe the effects of print settings on print paths before finalizing the g-code. Three validation tests were conducted to demonstrate the 3D printer’s ability to print ultra-soft silicone with the desired range of stiffness, change between materials quickly, and print a material stiffness gradient. Two types of VF models were printed in this study, a previously-designed model with multiple distinct layers (“EPI” model), and the same model but with a vertical stiffness gradient (VSG) in the superficial lamina propria layer. The EPI model was chosen to demonstrate the ability to 3D print a multi-layer model, and the VSG model was chosen to demonstrate the ability to print multi-material VFs with geometric and material properties that are difficult to fabricate using traditional casting methods. Sixteen VFs (i.e., eight pairs) of each model type were printed, and their vibratory responses were recorded, including onset pressure, frequency, and glottal width. A micro-CT scanner was used to evaluate the external geometric accuracy of the models. One-centimeter cubes were 3D printed and tensile tested to characterize the material properties of each set of VF models. The material and phonatory properties of both the EPI and VSG VF models were found to be comparable to human data and to previous data acquired using synthetic VF models fabricated via other methods. In this thesis, the 3D printing methodology is summarized, the setup and results of the validation and VF model tests are reported and discussed, and recommendations for future work are provided.

Synthetic, self-oscillating vocal fold (VF) models are physical models whose life-like vibration is induced and perpetuated by fluid flow. Self-oscillating VF models, which are often fabricated life-size from soft silicone elastomers, are used to study various aspects of voice biomechanics. Despite their many advantages, the development and use of self-oscillating VF models is limited by the casting process used to fabricate the models. Consequently, this thesis focuses on the development of 3D printing processes for fabricating silicone VF models. A literature review is first presented which describes three types of material extrusion 3D printing processes for silicone elastomers, namely direct ink writing (DIW), embedded 3D printing, and removable-embedded 3D printing. The review describes each process and provides recent examples from literature that show how each has been implemented to create silicone prints. An embedded 3D printing process is presented wherein a set of multi-layer VF models are fabricated by extruding silicone ink within a VF-shaped reservoir filled with a curable silicone support matrix. The printed models successfully vibrated during testing, but lacked several desirable characteristics which were present in equivalent cast models. The advantages and disadvantages of using this fabrication process are explored. A removable-embedded 3D printing process is presented wherein shapes were fabricated by extruding silicone ink within a locally-curable support matrix then curing the silicone ink and proximate matrix. The printing process was used to fabricate several geometries from a variety of silicone inks. Tensile test results show that printed models exhibit relatively high failure strains and a nearly isotropic elastic modulus in directions perpendicular and parallel to the printed layers. A set of single-material VF models were printed and subjected to vibration testing. The printed models exhibited favorable vibration characteristics, suggesting the continued use of this printing process for VF model fabrication. A micro-slicing process is presented which is capable of creating gcode for 3D printing multiple materials in discrete and mixed ratios by utilizing a previously-sliced single-material shape and a material definition. An important advantage of micro-slicing is its ability to create gcode with a mixed-material gradient. Initial test results and observations are included. This micro-slicing process could be used in material extrusion 3D printing

Optical resonators are structures that allow light to circulate and store energy for a duration of time. This work primarily looks at the fabrication, characterization, and application of whispering gallery mode microresonators and the analysis of organic photonic crystal-like structures and simulation of their resonant effects. Whispering gallery mode (WGM) microresonators are a class of cylindrically symmetric optical resonator which light circulates around the equator of the structure. These resonators are named after acoustic whispering galleries, where a whisper can be heard anywhere along the perimeter of a circular room. These optical structures are known for their ultra high Q-factor and their low mode volume. Q-factor describes the photon lifetime in the cavity and is responsible for the energy buildup within the cavity and sharp spectral characteristics of WGM resonators. The energy buildup is ideal for non-linear optics and the sharp spectral features are beneficial for sensing applications. Characterization of microbubble resonators is done by coupling light from a tunable laser source via tapered optical fiber into the cavity. The fabrication of quality tapered optical fiber on the order of 1-2 μm is critical to working on WGM resonators. The measurement of Q-factors up to 2x10⁸ and mode spectra are possible with these resonators and experimental techniques. This work focuses on microdisk and microbubble WGM resonators. The microdisk resonators are fabricated by femtosecond laser micromachining. The micromachined resonators are fabricated by ablating rotating optical fiber to generate the disk shape and then heated to reflow the surface to improve optical quality. These resonators have a spares mode spectrum and display a Q factor as high as 2x10⁶. The microbubble resonators are hollow microresonators fabricated by heating a pressurized capillary tube which forms a bubble in the area exposed to heat. These have a wall thickness of 2-5 μm and a diameter of 200-400 μm. Applications in pressure sensing and two-photon fluorescence of dye in microbubble resonators is explored. Photonic crystals can have engineered resonant properties by tuning photonic band gaps and introducing defects to create cavities in the photonic structure. In this work, a natural photonic crystal structure is analyzed in the form of diatoms. Diatoms are a type of phytoplankton which are identified by unique ornamentation of each species silica shell, called a frustule. The frustule is composed of a quasi-periodic lattice of pores which closely resembles manmade photonic crystals. The diatom frustules are analyzed using image processing techniques to determine pore-to-pore spacing and identify defects in the quasi-periodic structure which may contribute to optical filtering and photonic band gap effects. The data gathered is used to simulate light propagation through the diatom structure at different incident angles and with different material properties and to verify data gathered experimentally.

The past decade spotlighted a trend, which is that of individual users taking the role of innovators and physically creating their own products by explooting model additive manufacturing techniques. This trend emphasized the need for facilities able to serve as a platform for passionate makers to share knowledge, meet others and provides opportunities to realize their ideas. One of these platforms is Karlskrona Makerspace (KMS). KMS is located at Blekinge Institute of Technology (BTH) and provides 3D printing service, CNC milling machine and other facilities to help companies and individuals build physical prototypes. The purpose of this thesis is to expand the business of KMS and offer their service to more people. The study collects customer needs from potential KMS customers and aims at obtaining a viable business model after ranking risks. The main methodology used for building a business model is Running Lean Methodology to clear up complex associations in a business. The result shows that the business model identifies target customers, and clarifies the solutions to increase funding for KMS.

A polygon mesh, or a 3D mesh, consisting of a collection of vertices, edges, and polygons in three-dimensional space, is the standard way of representing 3D objects. In practice, polygon meshes acquired from the 3D scanning process fail to meet the quality requirements for most practical applications. Mesh defects like holes, duplicate elements, non-manifold elements are introduced during the scanning process, which lowers the quality of the output meshes. In this thesis, we describe a complete mesh-repairing process that fixes all defects within a polygon mesh. This process is divided into two parts: the mesh-cleaning part and the hole-filling part. In the mesh-cleaning part, we describe the ways of repairing different types of mesh defects. In the hole-filling part, we discuss two main hole-filling approaches: the surface-based method and the volumetric. In addition, we present a hybrid algorithm by combining the surface-based approach and the volumetric approach. We compare the meshes created by different hole-filing algorithms and show that the new algorithm is a good alternative to the existing ones. / Thesis (Master, Computing) -- Queen's University, 2013-09-11 23:45:08.591

We analyse the problem of creating didactic material for teaching and evaluating mathematics in the first year of a School of Architecture. By using visual programming, science professor used codes (formulae) to represent in a software their proposals, instead of drawing them themselves. Through this experience we create a database of codes with computational solutions that allows faculty to modify, reuse, visualise and print in the same platform that she students will use while developing their designs. In this way we aim to maximise the link between mathematics and design as fundamental base for the control of complex shapes.

The ease of manufacturing using additive manufacturing (3D-Printing) reduces the overall production cost compared with the traditional manufacturing techniques. Because of the benefits of 3D printing technologies, it is proposed to be used in manufacturing of different products. But there are some flaws that are causing significant effect on 3D printed models which degrades the quality of the product. Hence in order to handle these defects, different measurement techniques are needed to quantify the defects that are seen on the surface of 3D-printed models. In our study there are two experimental setups. Experimental setup one was made to find out the proper coating timing to enable measurement using two good samples without defects in different colors blue and red with same material. Different 2D and 3D parameters were used for the surface measurements are collected and noted for further research. The Defective samples are measured using the state of the art equipment at Halmstad University. Experimental setup two was made to prepare the defective samples and measure the samples. The results obtained assisted to quantify the surface defects seen in the samples. This thesis studies some of the different methods that can be implemented to measure the surface defects on the 3D printed models. A little study on the various defects formed on the 3D printed models and what are the causes for the defects on the products were performed. The results suggest different method for the defects to be measured in both industrial and home or small scale office applications.

Master of Science / Department of Biological & Agricultural Engineering / Mei He / Anemia affects about 25% of the world’s population and causes roughly 8% of all disability cases. The development of an affordable point-of-care (POC) device for detecting anemia could be a significant for individuals in underdeveloped countries trying to manage their anemia. The objective of this study was to design and fabricate a 3D printed, low cost microfluidic mixing chip that could be used for the diagnosis of anemia. Microfluidic mixing chips use capillary flow to move fluids without the aid of external power. With new developments in 3D printing technology, microfluidic devices can be fabricated quickly and inexpensively. This study designed and demonstrated a passive microfluidic mixing chip that used capillary force to mix blood and a hemoglobin detecting assay. A 3D computational fluid dynamic simulation model of the chip design showed 96% efficiency when mixing two fluids. The mixing chip was fabricated using a desktop 3D printer in one hour for less than $0.50. Blood samples used for the clinical validation were provided by The University of Kansas Medical Center Biospecimen Repository. During clinical validation, RGB (red, green, blue) values of the hemoglobin detection assay color change within the chip showed consistent and repeatable results, indicating the chip design works efficiently as a passive mixing device. The anemia detection assay tended to overestimate hemoglobin levels at lower values while underestimating them in higher values, showing the assay needs to go through more troubleshooting.

In today’s world regulations to reduce vehicle emissions are only gettingtougher, from said regulations the concept of a Selective Catalytic Reduction(SCR) unit was born, designed to provide a healthy dose of ammonia (NH3)to reduce the NOx compound into harmless components such as water andnitrogen. In this thesis novel approaches where investigated, by combiningthe fast physical absorption and desorption properties of a highly porous ma-terial such as zeolites with the high storage capacity of metal chlorides wecan potentially improve NH3 dosing in the low temperature operating range,such as when vehicles have just been turned on. Additive manufacturing pro-vides a faster and convenient processing route, that can cut down costs andallows for an inexpensive prototyping phase. With the aid of 3D printing weprepared a prototype cage-like shape using zeolite 13X with a combination ofPVP, binders and solvent,this structures would be used in conjunction withMgCl2, the latter would be enclosed the cage and so that their volume ex-pansion could be contained. This approach provides a low temperature rangefriendly solution for the release of NH3 in a SCR unit. The experimentationand characterization of the composites mixed by mechanical process showedgreat promise of what it can be achieved by incorporating zeolites and metalchlorides for ammonia storage and dosing. In the end a successful formulaand process to 3D print zeolite 13X using a PAM approach was deliveredthat showed similar results to untreated 13X.