Tissue paper is a type of soft, absorbent, and lightweight paper with several applications for hygiene and kitchen use. Embossing is an operation during the converting stage of the tissue production process which creates relief designs on tissue. Other than producing designs for aesthetic purposes, embossing increases bulk which improves absorbency and softness but reduces mechanical strength and stiffness. A computational model using the finite element method is developed to simulate the embossing of tissue paper. A tool for fitting an appropriate material model for tissue to its experimental test data is implemented. The material model is subjected to a verification test and it works sufficiently well to model the in-plane elastic and plastic anisotropic behavior of tissue. Two validation tests are conducted to check the embossing model against experimental test data where it is observed that the model works well. Firstly, it provides an idea about the amount of pressure required to be applied during loading to reach a certain embossing level. Secondly, it predicts the tensile strength of embossed tissue sheets although it provides a slight underestimate. Potential reasons for the shortcomings in the tensile strength are suggested and recommendations for further improving the model are provided. Lastly, parametric studies are conducted to investigate the influence of embossing pattern geometry on the mechanical performance of embossed tissue.  After passing the verification and validation stages, the model is ready to serve as a convenient, less time-consuming, and cost-effective alternative to experimental testing to study the embossing process. It can also be used as a tool to examine the effect of one or more model parameters on embossing by simply changing them and studying the new results. / Mjukpapper är ett mjukt och absorberande papper med låg ytvikt för hygien- och köksändamål. Prägling är en operation under konverteringsstadiet av produktionsprocessen som skapar reliefmönster på mjukpapperet. Förutom att skapa mönster för estetiska ändamål, ökar präglingen bulken som förbättrar absorptionskapacitet och mjukhet men den minskar mekanisk styrka och styvhet.En beräkningsmodell med finita element-metoden utvecklas för att simulera prägling av mjukpapper och ett verktyg för att koppla en lämplig materialmodell för mjukpapper till dess experimentella testdata implementeras. Materialmodellen genomgår ett verifieringstest och det fungerar tillräckligt bra för att modellera det elastisk-plastiska anisotropiska beteendet hos mjukpapper i planet. Två valideringstester utförs för att kontrollera präglingsmodellen mot experimentella testdata där det observeras att modellen fungerar bra. För det första ger den en uppfattning om mängden tryck som behöver appliceras för att nå en viss präglingsnivå. För det andra förutspår den draghållfastheten hos präglade mjukpappersark även om det ger en liten underskattning. Potentiella orsaker för bristerna i draghållfasthet föreslås och rekommendationer för ytterligare förbättringar av modellen ges. Slutligen genomförs parametriska studier för att undersöka påverkan av präglingsmönstergeometri på den mekaniska prestandan hos präglat mjukpapper. Efter att ha klarat verifierings- och valideringsstegen är modellen redo att fungera som ett lätthanterligt, mindre tidskrävande och mer kostnadseffektivt alternativ till experimentell testning för att studera präglingsprocessen. Det kan också användas som ett verktyg för att undersöka effekten av en eller flera modellparametrar på prägling genom att helt enkelt ändra dem och studera de nya resultaten.

<p>U disertaciji su predstavljena istraživanja uticajnih parametara u procesu izrade alata za utiskivanje tehnikom aditivne proizvodnje, tačnije tehnikom deponovanja istopljenog materijala (FDM). Izrađena je kontrolna grupa alata za utiskivanje konvencionalnom tehnikom hemijskog nagrizanja i SLA tehnikom 3D štampe. Cilj istraživanja je definisanje optimalnih procesnih parametara izrade alata za<br />utiskivanje FDM tehnikom štampe. Ustanovljena je metodologija za karakterizaciju proizvodnih parametara koja se može primeniti na ostale tehnike aditivne proizvodnje. Analizom dobijenih rezultata i zaključaka istraživanja ustanovljena su ograničenja i mogućnosti zamene konvencionalnih alata za utiskivanje alatima izrađenim tehnikama 3D štampe.</p> / <p>The study of the influencing parameters in the production process of embossing dies using Fused Deposition Modelling (FDM) additive manufacturing technique, was investigated in this dissertation. Embossing dies, produced using conventional chemical etching and vat photopolymerization technique, were developed as a control group. This research aims to define the optimal process parameters of Fused Deposition Modelling (FDM) in embossing dies manufacturing. A new methodology for the characterisation of production parameters, which can be applied to other additive production techniques, has been established. By analysing the results and the conclusions of this research, the possibility of replacing<br />conventional embossing dies produced using 3D printing techniques has been established as well as its limitations.</p>

<p>The interest for miniaturisation in chemical and biological analysis has increased in recent years. In this work, the design, fabrication and characterisation of tools for microanalysis have been studied. The focus is set on polymer microchips for applications in chemical analysis. The work consists of three parts: design and fabrication of paraffin microactuators, design and fabrication of polymer microchips as interfaces in electrospray ionisation mass spectrometry (ESI-MS), and characterisation of conducting films for fused silica capillaries as interfaces in ESI-MS.</p><p>The principle of the paraffin actuators is based on the volume increase resulting from paraffin melting. Paraffin expansion is utilised to cause membrane deflection. The first plastic microactuator using paraffin as the actuator material was successfully demonstrated.</p><p>The microchips as interfaces in ESI-MS have been designed with the objective that the interface should be as much a part of the microchip as possible, and as to as large extent as possible, be fabricated in the same step as the microchannels. Sheathless electrospray from microchips was demonstrated for the first time. In addition a simplified fabrication process for ESI-MS interfaces in poly(dimethyl siloxane) (PDMS) was developed.</p><p>The degradation of conductive coatings for sheathless ESI-MS on fused silica capillaries was studied. It was shown that electrochemical experiments could successfully be used to simulate the electrospray conditions and predict the failure of different gold coatings.</p><p>It was concluded that a common issue in the fabrication of thermoplastic microchips is the crucial sealing of microchannels and cavities. From this point of view, PDMS is a more advantageous material in microfluidics.</p>

The interest for miniaturisation in chemical and biological analysis has increased in recent years. In this work, the design, fabrication and characterisation of tools for microanalysis have been studied. The focus is set on polymer microchips for applications in chemical analysis. The work consists of three parts: design and fabrication of paraffin microactuators, design and fabrication of polymer microchips as interfaces in electrospray ionisation mass spectrometry (ESI-MS), and characterisation of conducting films for fused silica capillaries as interfaces in ESI-MS. The principle of the paraffin actuators is based on the volume increase resulting from paraffin melting. Paraffin expansion is utilised to cause membrane deflection. The first plastic microactuator using paraffin as the actuator material was successfully demonstrated. The microchips as interfaces in ESI-MS have been designed with the objective that the interface should be as much a part of the microchip as possible, and as to as large extent as possible, be fabricated in the same step as the microchannels. Sheathless electrospray from microchips was demonstrated for the first time. In addition a simplified fabrication process for ESI-MS interfaces in poly(dimethyl siloxane) (PDMS) was developed. The degradation of conductive coatings for sheathless ESI-MS on fused silica capillaries was studied. It was shown that electrochemical experiments could successfully be used to simulate the electrospray conditions and predict the failure of different gold coatings. It was concluded that a common issue in the fabrication of thermoplastic microchips is the crucial sealing of microchannels and cavities. From this point of view, PDMS is a more advantageous material in microfluidics.

This report outlines the conceptual, procedural and formal descriptions of the artistic development I have acquired over the course of the past three years. The current violent events caused by the War on Drugs in México –my home country- led me to this research. Beginning with the idea of erasure as language, I concentrated on the use of processes that are reductive in nature to create the bodies of work mentioned in this report. Thousands of people die in drug-related violence every year in México; by using metaphors and visual metonymies to tie together process and subject matter I explore the idea of perception, memory and transformation. I believe my work is derived from a need to find meaning in these brutal events that repositions the corpse in our field of vision, reminding us that our physical existence is finite. / text

The current trend in pushing photo lithography to smaller and smaller resolutions is becoming increasingly difficult and expensive. Extreme ultra-violet lithography is an alternate method that has the potential to provide feature sizes down to 30 nm, however, it will come at an even greater cost. Nanoimprint lithography (NIL) is another lithographic technique which is promising to provide very high resolutions at a relatively low cost. Imprinting works by using a mold with a surface patterned with the required nano structures and pressing it into a substrate coated with a deformable polymer. Due to its direct pattern replication technique, it is very capable of reproducing three-dimensional structures, however limited research has been performed on this to date. In this study, investigations have been performed into developing a reliable process for creating SiN molds with sub-100 nm structures with variable height control. The process relies on a negative tone electron beam resist which can be patterned to various thicknesses by varying the exposure dosage. This allows for the creation of complex multi-layer structures in a single electron beam lithography step. These patterns then have been transferred into the SiN substrate by a single reactive ion etch. From here the mold is ready for use in imprinting. Study has also been performed into imprinting process as well. This includes the development of an imprint press, the manner in which NIL works. Investigations have been performed into the imprinting performance of 3D molds. Thermal expansion issues have been found and addressed, as have adhesion problems. Some other aspects of 3D NIL which have not been addressed in this study have been outlined in future work for further investigation.

Ziel dieser Masterarbeit ist die Untersuchung neuartiger Prägeformkonzepte hinsichtlich ihres Prägeverhaltens. Die Konzepte weisen lokal unterschiedliche Materialeigenschaften auf, die zu einer verbesserten Ausprägung von Karton führen sollen. Die Konzepte sollen anhand der Prägeergebnisse und der Abformgenauigkeit evaluiert werden. Dabei ist ein weiteres Ziel der Arbeit, Methoden zur Quantifizierung der Abformgenauigkeit zu finden. Die Herstellung der Konzepte erfolgt mithilfe eines additiven Fertigungssystems, welches mehrere Materialien in einem Bauvorgang verarbeiten kann. Zur Datengewinnung werden Oberflächenscans der geprägten Kartonproben und Werkzeuge durchgeführt. Auf Grundlage dieser Scans werden drei Methoden zur Ermittlung der Abformgenauigkeit vorgeschlagen. Abschließend werden die Werkzeuge anhand der Prägeergebnisse und der ermittelten Abformgenauigkeit bewertet. Weiterhin werden die vorgeschlagenen Methoden miteinander verglichen und deren Vor- und Nachteile diskutiert. Dies gibt Auskunft darüber, unter welchen Bedingungen der Einsatz welcher Methode sinnvoll erscheint.:1. Einleitung 2. Theoretische Grundlagen 2.1 Umformprozesse 2.1.1 Prägen von Faserwerkstoffen 2.1.2 Einsatz von Niederhaltern beim Umformen von Blechen 2.1.2.1 Tiefenziehen 2.1.2.2 Tiefen 2.1.3 Einsatz von Niederhaltern beim Umformen von Karton 2.1.3.1 Ziehen und Pressformen 2.1.3.2 Hydroformen 2.2 Multi-Material-Verarbeitung in der additiven Fertigung 2.2.1 Materialextrusion 2.2.2 Badbasierte Photopolymerisation 2.2.3 Material Jetting 2.2.4 Pulverbettbasiertes Schmelzen 2.2.5 Workflow und Datenvorbereitung 2.3.6 Geeignete Dateiformate 2.3 Soll-Ist-Vergleich von 2.5D-Oberflächendaten 2.3.1 Berechnung von Flächeninhalten und Volumen 2.3.2 Registrierung und Abstandsberechnung von Punktwolken 3. Versuche und Messungen 3.1 Herstellung der Prägeformkonzepte 3.1.1 Beschreibung der Konzepte 3.1.2 Fertigungstechnologie und Materialwahl 3.1.3 Datenvorbereitung für die Polyjet-Fertigung 3.2 Prägeversuche und Datenverarbeitung 3.2.1 Prägeversuche 3.2.2 Oberflächenscan am Keyence 3D-Makroskop 3.3 Ermittlung der Abformgenauigkeit 3.3.1 Flächen- und Volumenberechnung in MatLab & CloudCompare 3.3.2 Abformgenauigkeit nach ICP-Algorithmus & Abstandsberechnung 4. Ergebnisse und Diskussion 4.1 Betrachtung der Prägewerkzeuge 4.2 Betrachtung der Kartonprägungen 4.2.1 Prägeergebnisse nach Flächeninhalt der Profilschnitte 4.2.2 Einfluss der Faserlaufrichtung auf Kartonprägungen 4.2.3 Prägeergebnisse nach Volumen der Punktwolken 4.3 Betrachtung der Abformgenauigkeit 4.3.1 Abformgenauigkeit nach Flächeninhalt & Volumen 4.3.2 Abformgenauigkeit nach ICP-Algorithmus & Abstandsberechnung 4.4 Bewertung der Methoden zur Ermittlung der Abformgenauigkeit 4.5 Beurteilung des Bedienereinflusses bei der Datenverarbeitung am Keyence 5. Zusammenfassung und Ausblick Literaturverzeichnis Eidesstattliche Erklärung / The aim of this master thesis is to investigate novel embossing die concepts with regard to their embossing behavior. The concepts have locally different material properties, which should lead to an improved embossing of cardboard. The concepts are to be evaluated on the basis of the embossing results and the impression accuracy. A further aim of the work is to find methods for quantifying the impression accuracy. The concepts will be manufactured using an additive manufacturing system that can process multiple materials in a single build process. Surface scans of the embossed cardboard samples and tools are performed to obtain data. Based on these scans, three methods are proposed to determine the impression accuracy. Finally, the tools are evaluated based on the embossing results and the determined impression accuracy. Furthermore, the proposed methods are compared with each other and their advantages and disadvantages are discussed. This provides information on the conditions under which the use of which method appears to be sensible.:1. Einleitung 2. Theoretische Grundlagen 2.1 Umformprozesse 2.1.1 Prägen von Faserwerkstoffen 2.1.2 Einsatz von Niederhaltern beim Umformen von Blechen 2.1.2.1 Tiefenziehen 2.1.2.2 Tiefen 2.1.3 Einsatz von Niederhaltern beim Umformen von Karton 2.1.3.1 Ziehen und Pressformen 2.1.3.2 Hydroformen 2.2 Multi-Material-Verarbeitung in der additiven Fertigung 2.2.1 Materialextrusion 2.2.2 Badbasierte Photopolymerisation 2.2.3 Material Jetting 2.2.4 Pulverbettbasiertes Schmelzen 2.2.5 Workflow und Datenvorbereitung 2.3.6 Geeignete Dateiformate 2.3 Soll-Ist-Vergleich von 2.5D-Oberflächendaten 2.3.1 Berechnung von Flächeninhalten und Volumen 2.3.2 Registrierung und Abstandsberechnung von Punktwolken 3. Versuche und Messungen 3.1 Herstellung der Prägeformkonzepte 3.1.1 Beschreibung der Konzepte 3.1.2 Fertigungstechnologie und Materialwahl 3.1.3 Datenvorbereitung für die Polyjet-Fertigung 3.2 Prägeversuche und Datenverarbeitung 3.2.1 Prägeversuche 3.2.2 Oberflächenscan am Keyence 3D-Makroskop 3.3 Ermittlung der Abformgenauigkeit 3.3.1 Flächen- und Volumenberechnung in MatLab & CloudCompare 3.3.2 Abformgenauigkeit nach ICP-Algorithmus & Abstandsberechnung 4. Ergebnisse und Diskussion 4.1 Betrachtung der Prägewerkzeuge 4.2 Betrachtung der Kartonprägungen 4.2.1 Prägeergebnisse nach Flächeninhalt der Profilschnitte 4.2.2 Einfluss der Faserlaufrichtung auf Kartonprägungen 4.2.3 Prägeergebnisse nach Volumen der Punktwolken 4.3 Betrachtung der Abformgenauigkeit 4.3.1 Abformgenauigkeit nach Flächeninhalt & Volumen 4.3.2 Abformgenauigkeit nach ICP-Algorithmus & Abstandsberechnung 4.4 Bewertung der Methoden zur Ermittlung der Abformgenauigkeit 4.5 Beurteilung des Bedienereinflusses bei der Datenverarbeitung am Keyence 5. Zusammenfassung und Ausblick Literaturverzeichnis Eidesstattliche Erklärung

Planar electronic devices represent an attractive approach towards roll-to-roll printed electronics without the need for the sequential, precisely aligned, patterning steps inherent in the fabrication of conventional ‘3D’ electronic devices. Self-switching diodes (SSDs) and in-plane-gate field-effect transistors (IPG-FETs) can be patterned using a single process into a substrate precoated with semiconductor.These devices function in depletion mode, requiring the semiconductor to be doped in order for the devices to function. To achieve this, a reliable and controllable method was developed for doping organic semiconducting polymers by the immersion of optimally deposited films in a solution of dopant. The process was shown to apply both semicrystalline and air-stable, amorphous materials indicating that the approach is broadly applicable to a wide range of organic semiconductors.Simultaneously with the development of the doping protocol specialised hot-embossing equipment was designed and constructed and a high-yielding method of patterning the structures of IPG-FETs and SSDs was arrived at. This method allowed for consistent and reliable patterning of features with a minimum line-width of 200nm.Following the development of these doping and patterning processes these were combined to fabricate controllably doped, functioning planar devices. SSDs showed true zero-threshold rectification behaviour with no observed breakdown in the reverse direction up to 100 V. IPG-FETs showed switching behaviour in response to an applied gate potential and were largely free of detectable gate leakage current, verifying the quality of the patterning process.Furthermore, high-performance semiconducting polymer PAAD was synthesised and characterised in field-effect transistors as steps towards its use in planar electronic devices. It was also shown that this material could be doped using the developed immersion doping protocol and that this protocol was compatible with top-gated device architectures and the use of fluoropolymer CYTOP as a dielectric.

Neste trabalho, diferentes tipos de microestruturas foram geradas por torneamento com ferramenta de diamante de ponta única e microendentação para serem replicadas através da prensagem a quente. Testes foram realizados para ser avaliada a geração destas microestruturas por dois métodos distintos: microdeformação e microusinagem, planejados para observar a replicação gerada por marca de endentação Vickers (piramidal) e, remoção de material (torneamento com ferramenta de diamante de ponta única). Uma revisão no processo de manufatura aplicada para a replicação de microestruturas é apresentada. Os materiais usados como molde e réplica foram o cobre eletrolítico e o polimetilmetacrilato (PMMA), respectivamente. Inicialmente, a usinabilidade do cobre eletrolítico foi avaliada sob diferentes condições de corte, a fim de determinar parâmetros apropriados de torneamento para obter um fino revestimento de superfície final (rugosidade). Observou-se que para avanços (f) de 10 mícrons por revolução e profundidade de corte (ap) de 5 mícrons, a superfície apresentou um baixo valor de rugosidade, isto é, 2,81 nm para rugosidade média (Ra) e 13,4 nm para rugosidade teórica (Rt). Além disso, observou-se que a microestrutura do material mostrou-se de fundamental papel na rugosidade, por conta da recuperação elástica dos grãos devido a anisotropia da estrutura policristalina do cobre. As microestruturas geradas para a replicagem foram: a) lente esférica, b) perfil senoidal e sulcos concêntricos. Os resultados mostraram que é viável a reprodução, com boa conformidade das microestruturas, por meio de prensagem a quente. Observou-se que as bordas e as superfícies finas com rugosidade em torno de 10 nm rms foram bem replicadas. / In this work, different types of microstructures were generated by single point diamond turning and microindentation for will replicated through the hot embossing. Tests were carried to evaluate the generation these microstructures by two distinct methods: micro-deformation and micro-machining, planned to observe the replication of the mark generated by the Vickers indenter (Pyramidal) and the latter by material removal (single point diamond turning). A review on several manufacturing processes applied to replication of microfeatures, is presented. The materials used as mould and replication workpiece were electroless copper and polymethylmethacrylate (PMMA), respectively. Initially, the machinability of electroless copper was evaluated under different cutting conditions to determinate appropriate turning parameters to obtain very fine surface finish (roughness). It was observed that for f = 10 microns of revolution (feed rate) and ap = 5 microns (depth of cut), the surface presented the roughness’ lowest value, i.e., 2,81 nm to medium roughness (Ra) and 13,4 nm to theoretical roughness (Rt). Moreover, it was observed that the microstructure of the material plays a fundamental role on roughness, because of the elastic recovery of grains due to the anisotropy of the polycrystalline structure of copper. The microfeatures generated were the following: a) spherical lens, b) sinusoidal profile and concentrical grooves. The results showed that it is feasible to reproduce, with good agreement, the microfeatures by means of hot embossing. It was observed that thin edges and fine surfaces with roughness around 10 nm rms were well replicated.

<p>This thesis comprises tribological studies of extremely well-defined surfaces of different designs. Both low-friction and high-friction surfaces were manufactured and experimentally evaluated.</p><p>In the low-friction studies, lithography and anisotropic etching of silicon was first used as a texturing technique. The textured surfaces were subsequently PVD coated with TiN or DLC to achieve tribologically relevant interfaces. The results showed that under starved lubricated conditions, fine surface textures lowered the coefficient of friction and the wear rate. It was shown that also the orientation of the texture is of major importance for the lubricating function.</p><p>Further, a novel embossing technique was developed, permitting texturing of steel and other materials. A micro mechanically designed diamond tool was used to emboss steel surfaces. The roller/piston contact from a hydraulic motor was simulated and introduction of an embossed texture on the piston decreased the level and the fluctuation of the friction. The effect of the texture was here similar to the effect of an additional polish step. However, in general it is not an easy task to substantially improve a boundary lubricated contact by introducing a texture. </p><p>Studies of high friction surfaces were performed on micro mechanically designed diamond surfaces equipped with sharp pyramids or ridges. Just as theory predicts, the coefficient of friction was dependent on the shape of the ploughing bodies, but not on the counter material or the load. The tested surfaces resulted in static coefficients of friction between 1.1 and 1.6, depending on surface design and orientation. These are extremely high values, and therefore very interesting for practical applications requiring a high static friction.</p><p>Conclusively, the present thesis shows that it is possible to design and produce surfaces both for improved lubrication in sliding contact and for substantially improved high friction performance in static contacts.</p>