Manufactured products, such as furniture, laminate flooring, and large signs, are very labour intensive, time-consuming, and costly to produce as they require multiple coating and cutting operations on a series of independent machines, which can each introduce manufacturing errors between the tools and the work piece. By combining the processes of printing and milling, printing integrated manufacturing has the potential to eliminate some of these steps, significantly reduce errors, and preserve resources. Inkjet printing is an ideal method for both image transfer and coating operations due to its non-contact method of directly depositing various types of fluid onto a substrate. With improved positioning accuracy and droplet miniaturisation, inkjet printing could even be used for future applications like the mass-production of MEMS devices, which are traditionally fabricated with a highly complex process involving photolithography. This thesis presents the integration of a Xaar 126 inkjet printing system with an existing industrial flatbed CNC router to develop a combined printing and cutting system. This integration required modification to the overall system through mechanical, electrical, and software means to the existing 3-axis CNC milling system. A secondary z-axis was installed onto the router gantry for positioning of the printheads relative to the substrate, which required development of a separate homing routine to consistently position the printheads to a specified location. Based on the identified frequency response of the machine, a loop-shaping controller was designed for improved y-axis positioning, which is one of the main contributions to droplet placement accuracy. This resulted in a continuous motion tracking accuracy within ±20.2 µm at 250 mm/sec along a print pass (measured by 1.22 nm resolution linear encoder), which is significantly better than the industrial benchmark of ±100 µm. Extensive image processing and calibration methods were utilised on various substrate preparations of paper, wood, and coatings, to demonstrate the capability of the printing system and quantify the quality of print resolution. Calibration results tested on high-gloss Hewlett-Packard paper showed that the swath angle could be aligned within ±1°. Also, bidirectional printing could be used to reduce print time by at least 15% in multi-colour printing with comparable droplet placement accuracy to unidirectional printing. The inkjet system was successfully used to print custom designs on paper and, to a certain extent, on medium density fibreboard at a feed rate of 250 mm/sec. It was difficult to achieve satisfactory image results on wood, as the wood or paint grain was visible through the ink. Thus, without a white pre-coat, the printed image would appear significantly darker than the original image, even after adjusting the image in a graphics editor. For better quality results, it is recommended that greyscale printheads be implemented for greater resolution and a UV system should be investigated for more versatility in printing on different substrates such as glass, metals, plastics, and ceramics.

Patterning of multi crystalline silicon Solar cell is prepared with photolithography etching. Electroless plating is used to get metallization of Nickel contacts. SEM analysis of Nickel deposition and measurement of contact resistance for series and shunt resistance is done. To increase the fill factor, the screen printed electrodes are subjected to different firing temperatures there by increasing the efficiency of solar cell. Nickel-silicide formation at the interface between the Silicon and Nickel enhances stability and reduces the contact resistance, resulting in higher energy conversion efficiency.

At the age of multi-media, portable electronic devices such as mobile phones, personal digital assistant and handheld gaming systems have increased the demand for high performance displays with low cost production. Inkjet printing color optical filters (COF) for LCD applications seem to be an interesting alternative to decrease the production costs. The advantage of inkjet printing technology is to be fast, accurate, easy to run and cheaper than other technologies. In this master thesis work, we used various disciplines such as optical microscopy, rheology, inkjet printing, profilometering and colorimetry. The specific aim of the thesis was to investigate the feasibility of using company-A pigment formulation in inkjet production of COF for active matrix LCD applications. Ideal viscosity parameters were determined from 10 to 20mPa·s for easy inkjet printing at room temperature. The red pigments used are fully dispersed into the solvent and present an excellent homogenous repartition after printing. Thickness investigations revealed that the printed COF were equal or slightly thicker than typically manufactured ones. The colorimetry investigations demonstrated color coordinates very close to the NTSC red standard. LED backlighting seems to be a valuable solution to combine with the printed COF regarding to the spectrum and color analysis. The results on this thesis will increase the understanding of inkjet printing company-A pigments to produce COF for LCD applications.

Manufactured products, such as furniture, laminate flooring, and large signs, are very labour intensive, time-consuming, and costly to produce as they require multiple coating and cutting operations on a series of independent machines, which can each introduce manufacturing errors between the tools and the work piece. By combining the processes of printing and milling, printing integrated manufacturing has the potential to eliminate some of these steps, significantly reduce errors, and preserve resources. Inkjet printing is an ideal method for both image transfer and coating operations due to its non-contact method of directly depositing various types of fluid onto a substrate. With improved positioning accuracy and droplet miniaturisation, inkjet printing could even be used for future applications like the mass-production of MEMS devices, which are traditionally fabricated with a highly complex process involving photolithography. This thesis presents the integration of a Xaar 126 inkjet printing system with an existing industrial flatbed CNC router to develop a combined printing and cutting system. This integration required modification to the overall system through mechanical, electrical, and software means to the existing 3-axis CNC milling system. A secondary z-axis was installed onto the router gantry for positioning of the printheads relative to the substrate, which required development of a separate homing routine to consistently position the printheads to a specified location. Based on the identified frequency response of the machine, a loop-shaping controller was designed for improved y-axis positioning, which is one of the main contributions to droplet placement accuracy. This resulted in a continuous motion tracking accuracy within ±20.2 µm at 250 mm/sec along a print pass (measured by 1.22 nm resolution linear encoder), which is significantly better than the industrial benchmark of ±100 µm. Extensive image processing and calibration methods were utilised on various substrate preparations of paper, wood, and coatings, to demonstrate the capability of the printing system and quantify the quality of print resolution. Calibration results tested on high-gloss Hewlett-Packard paper showed that the swath angle could be aligned within ±1°. Also, bidirectional printing could be used to reduce print time by at least 15% in multi-colour printing with comparable droplet placement accuracy to unidirectional printing. The inkjet system was successfully used to print custom designs on paper and, to a certain extent, on medium density fibreboard at a feed rate of 250 mm/sec. It was difficult to achieve satisfactory image results on wood, as the wood or paint grain was visible through the ink. Thus, without a white pre-coat, the printed image would appear significantly darker than the original image, even after adjusting the image in a graphics editor. For better quality results, it is recommended that greyscale printheads be implemented for greater resolution and a UV system should be investigated for more versatility in printing on different substrates such as glass, metals, plastics, and ceramics.

Inkjet printing of ceramic components and gold conductive tracks was carried out in this study. A commercial inkjet printer, designed for printing one layer of 2D images on paper, was modified to give adequate resolution, to reverse the substrate for overprinting many layers and to accommodate the increase in thickness of 3D components during printing. Ceramic inks were prepared by wet ball milling and printed to form 3D structures. The powders used were alumina, zirconia, lead zirconate titanate (PZT) and barium titanate. The substrate used for printing the ceramic parts was an overhead transparency. Methods to stop or reduce ink flow were devised and used during printing of the ceramic parts. The alumina and zirconia powders were used for the fabrication of multi-layered laminates. The lead zirconate titanate was used to fabricate components with pillars, walls, vertical channels and x-y-z channel network. During printing of the x-y-z channel network, carbon was used as a support structure and then removed during firing. Barium titanate and carbon powders were used to form the first storey of a capacitor with a multi-storey car park structure. The printed parts were pyrolysed and fired in an oxidising environment and then characterised with scanning electron microscopy. The causes of micro structural defects found were discussed and prevention methods suggested. Organic gold powder was dissolved in methanol and then printed on three different substrates to form conductive gold tracks. The substrates used included alumina, glazed tile and microscope glass slides. The printed tracks were fired in air. The decomposition characteristics of the organic gold compound were studied with TGA and Differential Scanning Calorimetry (DSC). Scanning electron microscope was used to examine the fired gold film for defects and conductivity measurement of the tracks was carried out with a programmable multimeter.

This work presents a novel means of producing thin-film light-emitting devices, functioning according to the principle of electroluminescence, using an inkjet printing technique. This study represents the first report of a light-emitting device deposited completely by inkjet printing. An electroluminescent species, doped zinc sulfide, was incorporated into a polymeric matrix and deposited by piezoelectric inkjet printing. The layer was printed over other printed layers including electrodes composed of the conductive polymer poly(3,4-ethylenedioxythiophene), doped with poly(styrenesulfonate) (PEDOT:PSS) and single-walled carbon nanotubes, and in certain device structures, an insulating species, barium titanate, in an insulating polymer binder. The materials used were all suitable for deposition and curing at low to moderate (<150°C) temperatures and atmospheric pressure, allowing for the use of polymers or paper as supportive substrates for the devices, and greatly facilitating the fabrication process. The deposition of a completely inkjet-printed light-emitting device has hitherto been unreported. When ZnS has been used as the emitter, solution-processed layers have been prepared by spin-coating, and never by inkjet printing. Furthermore, the utilization of the low-temperature-processed PEDOT:PSS/nanotube composite for both electrodes has not yet been reported. Device performance was compromised compared to conventionally prepared devices. This was partially due to the relatively high roughness of the printed films. It was also caused by energy level misalignment due to quantization (bandgap widening) of the small (<10 nm) nanoparticles, and the use of high work function cathode materials (Al and PEDOT:PSS). Regardless of their reduced performance, inkjet printing as a deposition technique for these devices presents unique advantages, the most notable of which are rapidity of fabrication and patterning, substrate flexibility, avoidance of material wastage by using drop-on-demand technology, and the need for only one main unit operation to produce an entire device.

This work presents a novel means of producing thin-film light-emitting devices, functioning according to the principle of electroluminescence, using an inkjet printing technique. This study represents the first report of a light-emitting device deposited completely by inkjet printing. An electroluminescent species, doped zinc sulfide, was incorporated into a polymeric matrix and deposited by piezoelectric inkjet printing. The layer was printed over other printed layers including electrodes composed of the conductive polymer poly(3,4-ethylenedioxythiophene), doped with poly(styrenesulfonate) (PEDOT:PSS) and single-walled carbon nanotubes, and in certain device structures, an insulating species, barium titanate, in an insulating polymer binder. The materials used were all suitable for deposition and curing at low to moderate (<150°C) temperatures and atmospheric pressure, allowing for the use of polymers or paper as supportive substrates for the devices, and greatly facilitating the fabrication process. The deposition of a completely inkjet-printed light-emitting device has hitherto been unreported. When ZnS has been used as the emitter, solution-processed layers have been prepared by spin-coating, and never by inkjet printing. Furthermore, the utilization of the low-temperature-processed PEDOT:PSS/nanotube composite for both electrodes has not yet been reported. Device performance was compromised compared to conventionally prepared devices. This was partially due to the relatively high roughness of the printed films. It was also caused by energy level misalignment due to quantization (bandgap widening) of the small (<10 nm) nanoparticles, and the use of high work function cathode materials (Al and PEDOT:PSS). Regardless of their reduced performance, inkjet printing as a deposition technique for these devices presents unique advantages, the most notable of which are rapidity of fabrication and patterning, substrate flexibility, avoidance of material wastage by using drop-on-demand technology, and the need for only one main unit operation to produce an entire device.

Inkjet printing is a mature technique for colourful graphic arts. It excels at customized, large area, high resolution, and small volume production. With the developments in conductive, and dielectric inks, there is potential for large area inkjet electronics fabrication. Passive radio frequency devices can benefit greatly from a printing process, since the size of these devices is defined by the frequency of operation. The large size of radio frequency passives means that they either take up expensive space “on chip” or that they are fabricated on a separate lower cost substrate and somehow bonded to the chips. This has hindered cost-sensitive high volume applications such as radio frequency identification tags. Substantial work has been undertaken on inkjet-printed conductors for passive antennas on microwave substrates and even paper, yet there has been little work on the printing of the dielectric materials aimed at radio frequency passives. Both the conductor and dielectric need to be integrated to create a multilayer inkjet printing process that is capable of making quality passives such as capacitors and inductors. Three inkjet printed dielectrics are investigated in this thesis: a ceramic (alumina), a thermal-cured polymer (poly 4 vinyl phenol), and a UV-cured polymer (acrylic based). For the conductor, both a silver nanoparticle ink as well as a custom in-house formulated particle-free silver ink are explored. The focus is on passives, mainly capacitors and inductors. Compared to low frequency electronics, radio frequency components have additional sensitivity regarding skin depth of the conductor and surface roughness, as well as dielectric constant and loss tangent of the dielectric. These concerns are investigated with the aim of making the highest quality components possible and to understand the current limitations of inkjet-fabricated radio frequency devices. An inkjet-printed alumina dielectric that provides quality factors of 200 and high density capacitors of 400 pF/mm2 with self-resonant frequencies into the GHz regime is developed in this thesis. A multilayer fully printed process is demonstrated using PVP dielectric and dissolving type vias, giving better than 0.1 ohm resistance. In the multilayer process, capacitors and inductors have self-resonant frequencies around 1GHz. These fully printed devices have quality factors less than 10. Finally, 3D inkjet-printed UV-cured material is utilized with a novel silver organo-complex ink at 80oC providing conductivity of 1x107 S/m. A lumped element filter is demonstrated with an insertion loss of only 0.8 dB at 1GHz. The combination of inkjet printing 3D polymer and conductive metal together allows for complex shapes. A fully printed antenna with 81% radiation efficiency is shown. With these promising results and future advances in conductive inks and low-loss dielectrics, the performance of inkjet passives could one day overcome conventional fabrication methods.

The aim of this work was to assess the feasibility of 3-D inkjet printing of elastomers in latex form to create a novel material that would offer shielding against electromagnetic interference (EMI). To achieve this aim it was necessary to characterise and select suitable materials, carry out ink jetting trials, modify the materials accordingly to improve the printability and assess post jetting conditions including drying and curing behaviour. Particle size, surface tension, and viscosity measurements were made for a series of elastomer latex materials and carboxylated styrene butadiene rubber (XSBR) latex was identified as the most suitable. Latex ink optimisation included dilution with water and the addition of a humectant, triethylene glycol monomethyl ether (TGME), which delayed drying and reduced nozzle blocking. The surface energy was measured for arrange of potential substrates and PET was identified as the most suitable, due to its relatively high surface energy which allowed for an ideal level of wetting and spreading. Analysis of the cross-sectional profiles of the printed samples by white light interferometry showed that drying during printing was an important issue for the latex ink. Ink jetting of a composite material with control of filler distribution was shown to be feasible when ten layers of conductive carbon black ink were deposited alternately between ten layers of XSBR ink. Printing was successfully carried out with a latex combined with a resorcinol resin which was subsequently cured, indicating that it should be possible to 3D print a thermoset elastomer in this way. Conductive carbon black was printed in various patterns onto PET sheet and the dielectric properties measured. Results indicated that at very low carbon contents, the printed patterns could provide EMI shielding. The research has shown that it is feasible to create a cured 3D elastomeric object containing filler with a controlled distribution that is capable of providing EMI shielding.

Heritage iron objects are ubiquitous in the archaeological assemblage, frequently covered in thick, chloride-containing corrosion layers. Accurate monitoring of their corrosion rates is crucial for continued preventative conservation. Measurement of storage environment corrosivity is commonplace for a variety of metals, but use un-corroded metal as a proxy. Corrosion rates measured will be different with respect to chloride infused and corroded artefacts and data recovered difficult to reconcile with actual artefact degradation. Electrical resistance corrosion monitors have been applied to create proxy corrosion rates for various metals in industry, academia and heritage contexts. Pre-corrosion of such has previously been shown to be effective in providing altered corrosion rates in atmospheric environments. This research sets out to develop and refine the manufacture of such probes, to create sensors which will corrode similarly to chloride infested heritage iron and can be used in heritage environments to inform conservation strategy. Photochemical milling was used to create ERCM. Salt loading on the surface was achieved through a piezoelectric inkjet printer, shown to be adept at printing a variety of salt concentrations (down to 4μg/cm) and patterns, with consistency, regularity and reliability. The results of the methodology show the potential of the technique for future salt loading and corrosion testing applications. Corrosion products were grown on the treated ERCM by controlled atmospheric corrosion, shown to create a constant corrosion layer, no significant localised corrosion and good reproducibility. The products formed were shown to be compositionally similar to those found on archaeological iron. The sensors have been tested in both stable and dynamic relative humidity environments, within a test chamber and in ersatz heritage type, desiccated boxes. The corrosion rates and reactions were compared to those of heritage iron. Pre-corroded ERCM are shown to give similar corrosion rates to heritage iron; though direct calibration was not possible, further research is likely to remedy this. The final outcomes of the project are discussed with respect to the closeness of fit between proxy and archaeological iron corrosion rate data, benefits and shortcomings of the system and how the corrosion data affects current conservation understanding. It is concluded that the technique can detect corrosion rates down to storage relative humidity levels, provides more accurate representation of corrosion rate for chloride infested iron objects than bare metal ERCM, can be calibrated to suite specific objects and could represent excellent cost-effectiveness for environmental monitoring in heritage institutions.