Inkjet printing technology has been developing rapidly during recent years, pressing the ink and paper manufacturers to develop a better understanding of the mechanism of fixation of inkjet dye into the substrate. The aim of the work described in this thesis was to investigate the three-dimensional distribution of inkjet dye in paper and the interaction between dye and paper using advanced fluorescence microscopy techniques, Confocal Laser Scanning Microscopy (CLSM), and Two-photon Fluorescence Lifetime Imaging Microscopy (2P-FLIM). It has been shown that CLSM is a valuable, non-destructive, rapid technique for threedimensional imaging of printed samples and evaluation of print quality. The intrinsic fluorescence of both the inkjet dye and the paper substrate can be used to determine the spread and penetration of ink droplets in different inkjet papers. The optical sectioning capability of CLSM enables the position of the ink layer relative to the paper surface and the penetration depth of the ink to be quantified. It was observed that while in the microporous type of inkjet paper the penetration depends on the quantity of ink in the printed sample, in the swellable type of inkjet paper the penetration is almost the same for different amounts of ink. 2P-FLIM has been employed to spatially map, in three-dimensions, fluorescence lifetimes by measuring the lifetime at each pixel in the image. Fluorescent molecules in both the ink and paper were analysed. Because the fluorescence lifetime is affected by the local molecular environment, the fluorescence lifetime maps provide information on the interaction between inkjet dye and paper. Analysis of fluorescence lifetime maps reveals the interaction between dye molecules and silica or alumina particles in the paper, variations of the molecular environment within a single ink dot and that interaction between dye and paper is affected by pH.

No description available.

One way of reducing the cost of crystalline silicon solar cell fabrication is by increasing the conversion efficiency of the device. However, most high efficiency solar cell designs require more complex fabrication methods that also increase the fabrication cost. Photolithography is an example of such an indispensable but costly process. The most common use for photolithography in solar cell fabrication is for dielectric patterning. In this thesis, inkjet printing is proposed as an alternative method for dielectric patterning in solar cell fabrication. There are two inkjet printing methods developed in this thesis. The indirect inkjet patterning method involves the deposition of a suitable plasticiser droplet onto an intermediate resin coating layer on top of the dielectric surface. Diethylene glycol and novolac resin are used as the plasticiser and coating layer respectively. The plasticiser changes the permeability of the affected region of the resin such that it becomes permeable to liquid dielectric etchants. When the resin layer is removed, the printed pattern is transferred to the dielectric layer. The optimised process produces round openings with diameters as small as 30-35 μm and continuous line patterns with width as narrow as 40-50 μm. The direct inkjet patterning method involves the deposition of liquid phosphorus dopant sources onto both silicon and dielectric surfaces. Two types of phosphorus sources are used: phosphoric acid and specially-formulated dopant sources. Narrow lines as wide as 15-20 μm are produced after appropriate surface treatments on both silicon and dielectric surfaces. Using this method, a process that simultaneously pattern the dielectric layer and diffuse the silicon underneath is developed. Various high efficiency solar cell structures such as selective emitter, localised contacts, surface texturing and edge isolation are demonstrated using the indirect inkjet patterning method. Both inkjet patterning methods are then used in the fabrication of a selective emitter solar cell. Fill factors in the range of 0.79-0.80 are shown to be achievable with both patterning methods, thus indicating the high quality metal-silicon contacts formed by these inkjet techniques.

[ES] La tesis que se presenta bajo el título Metodologías de transferencia mediante sistemas de impresión inkjet: Procesos para la creación gráfica digital, pretende mostrar desde una perspectiva conceptual y técnico-práctica la evolución en el desarrollo de procesos desde los sistemas de registro y reproducción electrónicos hasta las tecnologías de registro, producción y representación digital, mediante procesos híbridos, ampliando el campo para la creación de la gráfica digital especialmente con impresoras de inyección de tinta. Se analiza la situación contextual de la gráfica a través de un recorrido histórico que parte desde principios del siglo XX para comprender los cambios y planteamientos que se han producido en la concepción de la gráfica como un medio autosuficiente para la creación de obra de arte única. Además de la percepción de las imágenes a través de la tecnología y como esta ha repercutido en la reflexión de nuevos enfoques en el medio artístico. En este sentido, tratamos de conceptualizar el movimiento y la percepción que provoca el mundo digital sobre las imágenes a través de la transferencia, no solo como concepto que nos ayuda a comprender cómo influye la transmisión de códigos, sino también, como práctica artística para extraer y materializar el flujo digital, las imágenes intangibles y dotarlas de un estado háptico, convirtiéndolas en objetos físicos. Para dar corporeidad a las imágenes, en la investigación se propone una serie de procesos de transferencia realizados a partir de sistemas de impresión inkjet donde entran en juego factores como el soporte temporal, el medio reportador y el soporte definitivo, el cual se desvincula de la tradicionalidad gráfica, utilizando materiales diversos que aportan un valor añadido a la pieza. / [CA] La tesi que es presenta sota el títol Metodologies de transferència mitjançant sistemes d'impressió inkjet: Processos per a la creació gràfica digital, pretén mostrar des d'una perspectiva conceptual i tècnic-pràctica l'evolució en el desenvolupament de processos des dels sistemes de registre i reproducció electrònics fins a les tecnologies de registre, producció i representació digital, mitjançant processos híbrids, ampliant el camp per a la creació de la gràfica digital especialment amb impressores d'injecció de tinta. S'analitza la situació contextual de la gràfica a través d'un recorregut històric que parteix des de principis del segle XX per a comprendre els canvis i plantejaments que s'han produït en la concepció de la gràfica com un mitjà autosuficient per a la creació d'obra d'art única. A més de la percepció de les imatges a través de la tecnologia i com aquesta ha repercutit en la reflexió de nous enfocaments en el mitjà artístic. En aquest sentit, tractem de conceptualitzar el moviment i la percepció que provoca el món digital sobre les imatges a través de la transferència, no sols com a concepte que ens ajuda a comprendre com influeix la transmissió de codis, sinó també, com a pràctica artística per a extreure i materialitzar del flux digital, les imatges intangibles i dotar-les d'un estat hàptic, convertint-les en objectes físics. Per a donar corporeïtat a les imatges, en la investigació es proposa una sèrie de processos de transferència realitzats a partir de sistemes d'impressió inkjet on entren en joc factors com el suport temporal, el mig reportador i el suport definitiu, el qual es desvincula de la tradicionalitat gràfica, utilitzant materials diversos que aporten un valor afegit a la peça. / [EN] The thesis presented under the title Methodologies of transfer using inkjet printing systems: Processes for digital graphic creation, aims to show from a conceptual and technical-practical perspective the evolution in the development of processes from electronic recording and reproduction systems until digital recording, production and representation technologies, through hybrid processes, expanding the field for the creation of digital graphics. especially with inkjet printers. The contextual situation of graphics is analyzed through a historical journey that starts from the beginning of the 20th century to understand the changes and proposals that have occurred in the conception of graphics as a self-sufficient means for the creation of unique works of art. In addition to the perception of images through technology and how it has affected the reflection of new approaches in the artistic medium. These means that we try to conceptualize the movement and perception that the digital world provokes on images through transfer, not only as a concept that helps us understand how the transmission of codes influences, but also as an artistic practice to extract and materialize intangible images of the digital flow and endow them with a haptic state, turning them into physical objects. In order to give corporeality to the images, the research proposes a series of transfer processes carried out using inkjet printing systems where factors such as temporary support, informative support and definitive support come into play, which is detached from graphic traditionality, using different materials that provide added value to the piece. / Molina Guixot, C. (2023). Metodologías de transferencia mediante sistemas de impresión inkjet: Procesos para la creación gráfica digital [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/193072

An inkjet printer can deposit a very small volume of liquid with high positional accuracy, high speed and low cost. As a maskless, non-contact additive patterning method, inkjet printing technology is increasingly being explored as an alternative to lithography, etching and vapour deposition processes to pattern electrical conductors and thin films with applications in printed electronic devices. The functional inks used in many of the applications involve non-linear viscoelasticity and their behaviours in the context of inkjet printing have not been fully understood. This thesis aims to characterise Newtonian and non-Newtonian properties of inkjet fluids and identify the key parameters affecting drop impact and spreading processes. Various fluid characterisation techniques such as the filament stretching rheometer and piezoelectric axial vibrator are explored. We propose an experimental method to assess the jettability of non-Newtonian inkjet fluids, without using an inkjet print head. The oblique collision of two continuous liquid jets leads to the formation of a thin oval liquid sheet bounded by a thicker rim which disintegrates into ligaments and droplets. Under certain conditions the flow structure exhibits a remarkably symmetrical 'fishbone' pattern composed of a regular succession of longitudinal ligaments and droplets. Good correlation was found between the maximum included angle of the fishbone pattern and the maximum ligament length in the jetting experiments, which suggests that a test based on oblique impinging jets may be useful in the development of fluids for ink jet printing. High-speed imaging is used to analyse the impact and spreading of sub-30 μm drops of diethyl phthalate or polystyrene solutions in diethyl phthalate on to smooth glass surfaces with controlled wettability at speeds from 3 to 8 m s-1, under conditions representative of drop-on-demand inkjet printing. Data on drop height and spreading diameter are generated with high time and spatial resolution, over eight orders of magnitude in timescale. The effects of fluid viscosity and elasticity, which significantly affect jetting performance, are negligible throughout the whole deposition process, with no significant difference between spreading curves. The values of the fluid surface tension and the substrate wettability also have no effect on the kinematic, spreading or relaxation phases, but a marked influence on the wetting phase, in terms of the speed of expansion of the contact diameter and the final spreading factor.

Continuous InkJet (CIJ) printing is a common 2-Dimensional printing technique that creates jets of ink that breakup into drops as they are propelled towards a substrate to create a print. Inkjet printing has been used not only to print on paper, but to manufacture a variety of devices including OLEDs, solar cells and microfluidic devices. In many cases, the ‘ink’ consists of a polymer dissolved in a volatile solvent. As this ink is sprayed on to the substrate, the solvent evaporates, leaving the polymer behind as the print. The addition of the polymer alters the physics of the problem significantly enough that it varies greatly from jetting only a fluid with nothing dissolved in it. Polymers impart viscoelasticity to the solution, creating ink jets that are long-lived and difficult to break into droplets. In order to maintain the formation of drops in a repeatable, uniform fashion, a disturbance of known magnitude is imposed upon the jet. While jetting a liquid with no additives in it, this disturbance governed jet breakup leads to the formation of satellite drops, smaller drops of fluid in-between the main jet drops. Satellite drops are an undesirable occurrence in inkjet printing because of their unpredictable behavior and potential to affect the quality of the print. However, the addition of polymers to the liquid can control and potentially suppress the formation of these satellite drops, greatly improving the print quality. The elasticity of iv the polymer and its ability to influence the jet behavior and formation of satellite drops is highly dependent on multiple factors including the backbone rigidity, molecular weight and the concentration in which it is present in the fluid. Strongly viscoelastic effects have a marked effect on the jet and their presence can be quantified quite easily. However, some polymers show weak viscoelastic behavior while present in the ink fluids and may or may not affect the jetting process. The objective of this study is to examine such a class of polymeric fluids that are weakly viscoelastic in the context of inkjet printing and satellite drop formation. Firstly, the fluids are tested in an extensional rheology setup called Capillary Breakup Extensional Rheometry – Drop-on-Substrate (CaBER-DoS) to quantify their extensional properties. Then, they are tested in an emulated inkjet printing setup. The goal is to quantify the impact of the aforementioned factors on jetting and using satellite drop behavior as a guiding metric to understanding viscoelastic behavior in inkjet printing fluids.

Separation of hydrophilic inks such as pigmented inkjet and flexographic inks has been an issue in paper recycling since the beginning of their use. The use of inkjet printing is continuing to increase, and it does not appear that this increase will stop anytime soon. Because of this, it is essential to find an adequate method of deinking these inks for the recycling of paper products. There has been a significant amount of research on methods of improving deinking of these inks, but none have been effective up to this point. Additionally, there has been a significant amount of research studying the effects of deinking parameters on these inks, but there are still gaps in this knowledge. A thorough investigation of deinking chemicals and parameters was conducted in this research along with an investigation of the behavior of the hydrophilic inks during the paper recycling, such as the detachment and reattachment of the ink. Through this analysis, two novel deinking methods were developed to decrease the redeposition and improve the separation of these inks. These methods were adsorption deinking and Liquid Phase Plasma (LPP) treatment. Both of these methods were shown to improve the deinkability of hydrophilic inks. However, LPP treatment was also seen to have a negative impact when hydrophilic inks were mixed with traditional hydrophobic inks. It was hypothesized and shown that LPP treatment has a positive impact on deinking of hydrophilic inks but a negative impact on traditional inks, which led to the development of the adsorption deinking method that can deink both hydrophilic and traditional inks.

A high-speed, large-area technique capable of nanopatterning flexible substrates is highly desirable in several applications such as; 1) thin film photovoltaics (TFPV's), 2) flexible electronics, 3) optoelectronics, 4) energy storage devices and 5) biological applications. Flexible substrates are attractive as they can be lower in cost than traditional substrates, and provide the ability to perform continuous processing both of which are valuable for cost sensitive applications such as TFPVs. Also, flexible substrates can conform to non-planar surfaces and therefore provide versatility in applications such as wearable electronics and biomedical devices. In this thesis, a patterning approach known as Jet and Flash Imprint Lithography (J-FIL) is explored for flexible substrates. J-FIL uses inkjets to deposit low-viscosity UV curable polymer materials (resists) that are molded by a template at room temperature and low pressures prior to UV cross-linking. There are inherent advantages to the J-FIL process that lends itself to patterning flexible substrates. The room temperature and low pressure process makes it more compatible with flexible substrates which tend to become dimensionally unstable at elevated temperatures and pressure. The extension of J-FIL to flexible substrates involves the following key challenges: (i) Understanding the level of precision required in roll-to-roll machine systems to ensure that these systems can facilitate imprint and separation of nano-scale features; (ii) The substrate surface should be controlled to initiate and maintain proper interface with the template and avoid formation of bubbles; (iii) The tension in the film should be controlled to ensure that the discrete resist drops are coerced to form a uniform contiguous residual film underneath the patterns; (iv) The fluid filling time - that is representative of the process throughput - should be low; and (v) After UV curing and separation, the nanoscale patterns should not be deformed or damaged. The above challenges were addressed by developing a roll-to-roll test bed to imprint flexible polycarbonate films using the J-FIL process. The test bed has the capability of controllably varying a number of web tension parameters as well as process variables in order to calibrate machine precision and establish control schemes for a robust process. Process metrics such as RLT uniformity, target RLT accuracy, feature filling and feature distortion were measured and quantified. A design of experiments was performed on the test bed for the purposes tuning the process variables as well as developing a model of process performance, with respect to critical process parameters. A two-level design, with three input variables, is utilized in this experimental process. The process yielded blank imprints with mean thickness of 70.5 nm, and a standard deviation of 3.9 nm. The sensitivity of the mean thickness and uniformity to process variables were quantified. The best performing set of input parameters were then used during patterned imprints, to determine if any pattern filling issues or pattern deformation would take place. The patterned imprints, made up of an array of hexagonal pillars (125nm tall, by 240 nm wide, by 450 nm pitch) showed no sign of fluid filling voids, or deformation due to separation. Given this result, the feasibility of implementing J-FIL on a roll-to-roll prototype system was established. A proposed next generation flexible substrate J-FIL tool is presented, along with the expected challenges associated with metrology and dynamic noise. Future work entails the design and qualification of a full scale roll-based imprint tool, capable of meeting throughput metrics established for industrial applications. / text

Made available in DSpace on 2014-06-12T15:52:19Z (GMT). No. of bitstreams: 2 arquivo2841_1.pdf: 1812233 bytes, checksum: 78abbf363fbd42ac838d1798c601100f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Entre outras técnicas, os métodos eletroquímicos têm emergido como sendo atrativos devido à sua simplicidade, baixo custo, possibilidade de medição em tempo real e, geralmente, apresentarem alta sensibilidade. Neste estudo, foi desenvolvido um protótipo de um biossensor amperométrico de glicose, parcialmente baseado na tecnologia de impressão jato de tinta (Inkjet). Dois eletrodos foram confecionados pelo método screenprinting em uma fita de PVA (Polivinil Álcool). Em um deles, uma solução de glicose oxidase foi depositada por impresora a jato de tinta, modificada para os experimentos. O eletrodo de referência foi constituído de Ag /AgCl. Antes do processo de impressão, foi realizada uma verificação dos sitema impressor por Microscopia Eletrônica de Varredura, para avaliação dos poros de impressão. A Voltametria cíclica apresentou resposta linear entre concentração de glicose e os picos de corrente anódica em um mesmo intervalo de potencial, indicando a viabilidade do método. Neste trabalho também foi desenvolvido um genosensor para a detecção de sequências específicas de DNA transduzidas por Voltametria de Pulso Diferencial. Os eletrodos foram feitos pela imobilização de sequências de DNA em um eletrodo de ITO (Indium Tin Oxide) modificado com NaOH e APTES. Os resultados demonstraram um aumento do valor de corrente anódica (0,73 μA) quando a sequência de DNA estava presente no eletrodo, diferindo da corrente encontrada nos eletrodos sem a sequência imobilizada. Os resultados também mostraram que após a hibridização do DNA imobilizado com uma sequência complementar de uma região específica do vírus BPV contendo 27 bases, a corrente anódica diminuiu, indicando que o processo de hibridização ocorreu na superfície do eletrodo. A seqüência utilizada para a hibridização foi uma região específica do vírus BPV, contendo 27 bases. Os achados indicam que o eletrodo de ITO poderia ser um instrumento viável e de fácil manipulação para construção de biossensores de DNA

En los últimos años hemos vivido la aparición de nuevas tecnologías como la fotografía digital, así como los software y hardware para su tratamiento y reproducción. Estos recursos no han pasado desapercibidos para la disciplina de la restauración, introduciéndose poco a poco en algunas de sus intervenciones. En la actualidad, estas herramientas informáticas han abierto un campo de posibilidades infinitas en la reintegración cromática y están siendo utilizadas para la manipulación y el tratamiento digital de restos originales y de sus referencias históricas. Las ventajas que ofrecen son evidentes, ya que además de poder simular y concretar previamente la reconstrucción en entornos virtuales, permiten materializarla sobre el original de forma exacta, objetiva y sin errores. A pesar de los avances hechos hasta el momento, todavía existen algunas limitaciones en la fase de representación de la imagen impresa sobre el original. Como solución alternativa a los procedimientos actuales, esta tesis propone utilizar de forma directa los sistemas de impresión inkjet. Para conseguir demostrar la viabilidad de la propuesta, se han realizado una serie de prototipos de impresión directa. A partir de estas primeras experiencias de adaptación, se han desarrollado soluciones robotizadas optimizadas que ilustran virtualmente el concepto de lo que se busca conseguir: adaptar los dispositivos de impresión a cualquier tipología de superficie para reconstruir directamente las pérdidas pictóricas de una obra. Además, se han realizado una serie de pruebas de impresión sobre superficies murales que acreditan las ventajas de utilizar directamente los sistemas de impresión inkjet en la reconstrucción de originales. / Blanco-Moreno Pérez, FJ. (2014). RECONSTRUCCIÓN DE PINTURA MURAL MEDIANTE IMPRESIÓN DIRECTA CON SISTEMAS INKJET ROBOTIZADOS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37985 / TESIS