This thesis is the result of the investigation and solution of a mechanicalproblem regarding flywheel malfunctions. A flywheel is, in short, a devicethat relies on a rotating object’s moment of inertia to store energy overshort time spans. This project is part of the development of a fourthflywheel prototype at the division for electricity at Uppsala university,which uses magnetic levitation to keep a hollow cylinder rotating at veryhigh speeds inside a vacuum chamber. Should the magnets fail however, orsome other error occur that leads to an uncontrolled state of rotation, thecylinder needs to be stabilized mechanically by a device usually referredto as ‘back-up bearing’. This contraption might, like an airbag of a car,never be used but needs to be included if an emergency occurs to protectother parts of the flywheel which would otherwise be destroyed by theunrestrained rotor. A theoretical pre-study was conducted to determine what challenges andrespective solutions the design of such a device would encounter, forexample the amount of energy in the rotor and possible ways to dissipate itin the event of a malfunction. The benefits and downsides of materials andmachine elements such as bearings were investigated in order to design aset of backup bearings. The modelling was done using SolidWorks, which wasalso used to conduct thermal and mechanical simulations on differentconcepts. MatLab was used for calculations, using formulae from themanufacturers and from different websites. The project concluded that the sheer energy of the flywheel at top speedpresents considerable thermodynamic difficulties. A solution capable ofhandling this was however achieved, albeit barely. Unfortunately onlysimulations and calculations confirm this result as no practicalexperiments could be conducted, therefore caution is advised in futureexperiments where the flywheel speed approaches maximum levels.

O presente trabalho trata do projeto e da fabricação de uma mini máquina para usinagem de esferas cerâmicas verdes. Esferas de cerâmicas avançadas encontram grande aplicação em componentes de alta precisão como rolamentos híbridos ou como a cabeça de próteses de quadril. A grande demanda pelas esferas de cerâmicas avançadas nesses componentes se deve à combinação única de suas propriedades tais como: alta estabilidade dimensional, alta dureza, baixo coeficiente de expansão térmica, biocompatibilidade (bioinerte) e alta resistência mecânica à compressão. No entanto o alto desempenho só será alcançado se as esferas tiverem tolerâncias estreitas (dimensão e forma) e acabamento superficial ultrafino. Esse trabalho objetiva o projeto e a fabricação de um protótipo de mini máquina para usinagem de esferas cerâmicas prensadas de até 30 mm de diâmetro. O desenvolvimento do projeto foi dirigido por uma metodologia de projeto mecânico e após definição do conceito foi gerado um pré-projeto virtual seguido da fabricação de um protótipo, o conceito é composto por três rebolos, sendo dois de arraste que, tendo velocidades e direções de giro variáveis, promovem a variação do eixo de giro das esferas, parâmetro necessário para atingir baixo desvio de esfericidade. Blanks esféricos em zircônia foram conformados por prensagem isostática e usinados no protótipo construído. As esferas passaram pela caracterização metrológica através da medição de esfericidade, circularidade e acabamento superficial. / This work deals with the design and manufacturing of a mini machine for grinding of green ceramic balls. Balls of advanced ceramics find wide application in high-precision components such as hybrid bearings or as bearings of hip prostheses. The large demand for advanced ceramic balls in these components is due to their unique combination of properties such as high dimensional stability, high hardness, low coefficient of thermal expansion, biocompatibility (bio inert) and high compressive strength. However the high performance can only be achieved if the balls have narrow tolerances (size and shape) and ultra-fine surface finish. This work aims to design and manufacture a mini prototype machine to obtain a green ceramic balls up to 30 mm in diameter. The project development was driven by a mechanical design methodology and after the concept generation a virtual pre-design has been generated followed by manufacturing a prototype, the initial concept is composed of three wheels, two of drag that having variables turning speeds and directions, promote a random orbital effect in the balls necessary to reduce the sphericity error. Spherical zirconia blanks were shaped by isostatic pressing and machined in the built prototype. The balls were characterized by measuring sphericity error and surface roughness.

Flexible electronics have demonstrated potential in a wide range of applications including wearable sensors, photovoltaics, medical devices and more, due to their properties of extreme adaptability while also being lightweight and highly robust. The main challenge standing in the way of progress in this field is the difficulty of large-scale manufacturing of these flexible electronics compared to their rigid counterparts. Microcontact printing is a form of soft lithography in which an elastomeric stamp is used to transfer sub-micron scale surface patterns onto a flexible substrate via ink monolayers. The integration of microcontact printing into a roll-to-roll (R2R) system will enable continuous printing of flexible electronics and scale it up for massive manufacturing. The proposed thesis outlines a novel mechanical design for a microcontact printer which utilizes flexural motion stages with integrated position and force sensors to control the print process on a R2R system. The printhead is designed to fit the available space on the pre-installed UMass Amherst Intelligent Sensing Laboratory test table and breadboard. The R2R system includes motorized rollers for winding/unwinding the PET (polyethylene terephthalate) web substrate, and idler rollers for guiding a web through the print system. As the central element to this design, two matching plate flexures are designed on the two ends of the printer roller to control the tilting and positioning of the print roller. Flexure mechanisms rely on bending and torsion of flexible elements: this allows them to achieve much higher precision in positioning compared to conventional mechanisms which rely on surface interaction between multiple moving parts. The print resolution target for this design is 500 nm (linewidth), based on current state-of-the-art designs [1, 2]. In the initial version of the printhead design, a total of 33 parts are custom fabricated for assembly and installation in the R2R system lab setup. These include everything from the components of the print roller, specially adapted air-bearing mounts, support structures, and connectors. The design and 4 fabrication process for every component is outlined here along with the functionality, as every component was designed with the system objectives and constraints in mind. Using SolidWorks simulation, FEA (finite element analysis) is performed for every part of the assembly that is subjected to stress in the real system, so that predictions can be made about the displacement of the motion stages and the frequency of vibration. These predictions are evaluated by comparation with the experimental results from tests conducted on the real system hardware and used to assess the quality of the fabricated assembly. The work performed in this thesis enables advancements in the assembly of an updated, optimized R2R system and has led to an experimentally functioning lab setup that is ripe for further improvements. Completion and calibration of this augmented R2R system will, in future, enable UMass Amherst in-house production of large-area flexible electronics which may be used in a wide range of applications, including medical sensors, solar cells, displays, and more. In addition to microcontact printing, this R2R system may also be applied to nanoimprint lithography, another contact-based print method, or integrated with inkjet printing, a non-contact method.

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Possible modern application of piston steam engine is electricity production using steam made by solar energy. This diploma thesis focuses on designing such piston steam engine Described solution would be effective as an off grid electricity generator, because alternative source of steam could be added for occasions, when sunlight is not powerfull enough for steam production.

For Raman spectroscopy is a need to introduce a laser light into an optic fiber and analyze a collected light at the same time. Therefore it was proposed a specialized optical system. This system can also be used to measure other spectroscopy methods such as photoluminescence. In the theoretical part of this theses, was discussed both mentioned methods and their instrumentations. In addition to the Raman spectroscopy, was also shown some special cases of Raman spectroscopy for enhanced measurement of Raman scattering. The problem of weak signal detection and its reading is also discussed in the theoretical part of the thesis. In the practical part of this thesis was discussed the mechanical design of the optical system and the choice of optical elements that are used in the system. Next, is introduced the manufactured system, which design is based on the parameters of the chosen optical elements. The practical part of the thesis ends with an assembly and testing of the proposed system.

The continuously increasing demand of the customer requires equivalent response from the industry. This phenomenon of lean supply chain has also been seen in the paper and textile industries. TEXO AB produces customized weaving looms for the paper and textile industries. As every machine is redesigned to the customer requirements, TEXO needed to make the process efficient and effective. Once again the application of new computing technologies comes in handy. The practice of parametric design is applied to the TEXO’s FSX concept, which is one of the three weaving loom machine series supplied by TEXO. The frequent customization of FSX concept for each customer has created the need for faster redesign, better communication and quick order to suppliers. The automation is done on Autodesk Inventor using its iLogic and Shrinkwrap features. The parametric model is complete where all components to be customized are included. An excel sheet with design calculations, parameters and possible machine modules is developed together with the model. The feasibility of the automated design has been shown by the complete conformance of the model to the requirement. The excel sheet is very useful for improving the internal and external communications. After the completion of this project the redesign time is significantly reduced and the communication is simplified. It is also now possible to identify customization and module opportunities for future machines.

As a large generation ages, the collective financial and ethical responsibility to prevent egregious bodily harm through fall prevention and gait assistant exoskeleton devices increases. Risk for falls increases with age and the severity of the fall does as well. To support this elderly population, motorized exoskeletons can both increase stability as well as respond faster to fall scenarios, but current models do not more around the existing biological framework. Giving participants a range of motion in key pelvic areas can closely approximate synchronous rotation around the femoral head, while limiting an increase in their sagittal profile. Utilizing 3D printed components while incorporating existing orthic methods provide short production times on modular designs. Although primarily mechanically based, these designs consider electronic requirements and are capable for supporting movement for a 200 lbs. user at a brisk walking pace for 1 hour.

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