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Tehrani, Payman. "Electrochemical Switching in Conducting Polymers – Printing Paper Electronics." Doctoral thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15132.
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During the last 30 years a new research and technology field of organic electronic materials has grown thanks to a groundbreaking discovery made during the late 70’s. This new field is today a worldwide research effort focusing on exploring a new class of materials that also enable many new areas of electronics applications. The reason behind the success of organic electronics is the flexibility to develop materials with new functionalities via clever chemical design and the possibility to use low‐cost production techniques to manufacture devices. This thesis reports different aspects of electrochemical applications of organic electronics. We have shown that the color contrast in reflective and transmissive electrochromic displays can be almost doubled by adding an extra electrochromic polymer. The choice of electrochromic material was found to be limited by its electrochemical over‐oxidation (ECO) properties, which is one of the main degradation mechanisms found in displays. The irreversible and non‐conducting nature of over‐oxidized films encouraged us to use it in a novel patterning process in which polythiophene films can be patterned through local and controlled deactivation of the conductivity. ECO can be combined with various patterning tools such as screen printing for low‐cost roll‐to‐roll manufacturing or photolithography, which enables patterning of small features. Studies have shown that electronic conductivity contrasts beyond 107 can be achieved, which is enough for various simple electronic systems. To generate better understanding of the ECO phenomenon, the effect of pH on the over‐oxidation characteristics was studied. The results suggest that a part of the mechanism for over‐oxidation depends on the OH– concentration of the electrolyte used. Over‐oxidation has also been used in electrochemical loggers, where the temperature and time dependence of the propagation of an over‐oxidation front is used to monitor and record the temperature of a package.Dagligen kommer vi i kontakt med olika plastmaterial. Dessa har vanligtvis mycket dålig elektrisk ledningsförmåga och används oftast som isolerande material. Det finns dock en klass av plaster som är halvledande eller ledande. Sedan upptäckten av dessa material för mer än 30 år sedan har nya material och användningsområden utvecklats och nu börjar de första produkterna baserad på organisk elektronik komma ut på marknaden. En stor fördel med de ledande plasterna är att egenskaperna kan anpassas genom att ändra den kemiska strukturen. Man kan dessutom lösa upp dem och skapa ledande bläck, som sedan kan användas i vanliga tryckmaskiner. Detta gör det möjligt att på ett enkelt och billigt sätt tillverka elektronik på liknande sätt som till exempel tidningar trycks idag. Den här avhandlingen behandlar en del av det nya området som berör elektrokemiska komponenter och några av dess tillämpningar. Fokus ligger främst på billig, tryckt elektronik. Bland annat presenteras ett sätt att fördubbla kontrasten för tryckta pappersdisplayer, ett nytt sätt att mönstra ledande plaster och elektrokemisk temperaturloggningsetikett som kan övervaka temperaturen för förpackningar under transport. Den mekanism som förstör ledningsförmågan vid höga spänningar har varit ett återkommande inslag i de studier som har genomförts här. Denna mekanism förstör komponenterna under drift men kan också användas för att ta bort ledningsförmågan som mönstringsmetod eller för att lagra information, permanent, i temperaturloggningsetiketten.
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Yoshioka, Yuka. "Inkjet printing for fabrication of organic photonics and electronics." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280578.
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Organic light-emitting devices (OLEDs) are traditionally patterned either through vacuum deposition masks or by UV lithographs. However, such patterning routes are relatively expensive, time consuming, and geometry limited. On the other hand, developments in the use of inkjet printing as a tool to pattern a given electrode promise a low cost, maskless, and non-contact approach to generate a myriad of patterns. In this dissertation, I will present our exploratory works in ink jet printing techniques, to pattern conductive polymers for use as electrodes with predefined shapes and controlled conductivity. Our works have been extended to explore printing with multiple inks, which mix and/or react with each other, for the use in making artificial muscles and for the developments of inkjet combinatorial techniques. Many factors including surface tension of the printed solution, substrate surface properties, and drying conditions have a direct effect on the final quality and performance of the organic based devices. Issues related to device fabrication on flexible substrates will be discussed and the results of tested devices are shown.
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Mannerbro, Richard, and Martin Ranlöf. "Inkjet and Screen Printed Electrochemical Organic Electronics." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8117.
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Linköpings Universitet och Acreo AB i Norrköping bedriver ett forskningssamarbete rörande organisk elektrokemisk elektronik och det man kallar papperselektronik. Målet på Acreo är att kunna trycka denna typ av elektronik med snabba trycktekniker så som offset- eller flexotryck. Idag görs de flesta demonstratorer och prototyper, baserade på denna typ av elektrokemisk elektronik, med manuella och subtraktiva mönstringsmetoder. Det skulle vara intressant att hitta fler verktyg och automatiserade tekniker som kan underlätta detta arbete. Målet med detta examensarbete har varit att utvärdera vilken potential bläckstråleteknik respektive screentryck har som tillverkningsmetoder för organiska elektrokemiska elektroniksystem samt att jämföra de båda teknikernas för- och nackdelar. Vad gäller bläckstråletekniken, så ingick även i uppgiften att modifiera en bläckstråleskrivare avsedd för kontor/hemmabruk för att möjliggöra tryckning av de två grundläggande materialen inom organisk elektrokemisk elektronik - den konjugerade polymeren PEDOT och en elektrolyt.
I denna uppsats rapporteras om hur en procedur för produktion av elektrokemisk elektronik har utvecklats. Världens första elektrokemiska transistor som producerats helt med bläckstråleteknik presenteras tillsammans med fullt fungerande implementeringar i logiska kretsar. Karaktärisering av filmer, komponenter och kretsar som producerats med bläckstråle- och screentrycksteknik har legat till grund för den utvärdering och jämförelse som har gjorts av teknikerna. Resultaten ser lovande ut och kan motivera vidare utveckling av bläckstrålesystem för produktion av prototyper och mindre serier. En kombination av de båda nämnda teknikerna är också ett tänkbart alternativ för småskalig tillverkning.
Linköping University and the research institute Acreo AB in Norrköping are in collaboration conducting research on organic electrochemical electronic devices. Acreo is pushing the development of high-speed reel-to-reel printing of this type of electronics. Today, most demonstrators and prototypes are made using manual, subtractive patterning methods. More tools, simplifying this work, are of interest. The purpose of this thesis work was to evaluate the potential of both inkjet and screen printing as manufacturing tools of electrochemical devices and to conduct a comparative study of these two additive patterning technologies. The work on inkjet printing included the modification of a commercially available desktop inkjet printer in order to print the conjugated polymer PEDOT and an electrolyte solution - these are the two basic components of organic electrochemical devices. For screen printing, existing equipment at Acreo AB was employed for device production.
In this report the successful development of a simple system and procedure for the inkjet printing of organic electrochemical devices is described. The first all-inkjet printed electrochemical transistor (ECT) and fully functional implementations of these ECTs in printed electrochemical logical circuits are presented.
The characterization of inkjet and screen printed devices has, along with an evaluation of how suitable the two printing procedures are for prototype production, been the foundation of the comparison of the two printing technologies.
The results are promising and should encourage further effort to develop a more complete and easily controlled inkjet system for this application. At this stage of development, a combination of the two technologies seems like an efficient approach.
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Lim, Ying Ying. "Printing conductive traces to enable high frequency wearable electronics applications." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/17880.
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With the emergence of the Internet of Things (IoT), wireless body area networks (WBANs) are becoming increasingly pervasive in everyday life. Most WBANs are currently working at the IEEE 802.15.4 Zigbee standard. However there are growing interests to investigate the performance of BANs operating at higher frequencies (e.g. millimetre-wave band), due to the advantages offered compared to those operating at lower microwave frequencies. This thesis aims to realise printed conductive traces on flexible substrates, targeted for high frequency wearable electronics applications. Specifically, investigations were performed in the areas pertaining to the surface modification of substrates and the electrical performance of printed interconnects. Firstly, a novel methodology was proposed to characterise the dielectric properties of a non-woven fabric (Tyvek) up to 20 GHz. This approach utilised electromagnetic (EM) simulation to improve the analytical equations based on transmission line structures, in order to improve the accuracy of the conductor loss values in the gigahertz range. To reduce the substrate roughness, an UV-curable insulator was used to form a planarisation layer on a non-porous substrate via inkjet printing. The results obtained demonstrated the importance of matching the surface energy of the substrate to the ink to minimise the ink de-wetting phenomenon, which was possible within the parameters of heating the platen. Furthermore, the substrate surface roughness was observed to affect the printed line width significantly, and a surface roughness factor was introduced in the equation of Smith et al. to predict the printed line width on a substrate with non-negligible surface roughness (Ra ≤ 1 μm). Silver ink de-wetting was observed when overprinting silver onto the UV-cured insulator, and studies were performed to investigate the conditions for achieving electrically conductive traces using commercial ink formulations, where the curing equipment may be non-optimal. In particular, different techniques were used to characterise the samples at different stages in order to evaluate the surface properties and printability, and to ascertain if measurable resistances could be predicted. Following the results obtained, it was demonstrated that measurable resistance could be obtained for samples cured under an ambient atmosphere, which was verified on Tyvek samples. Lastly, a methodology was proposed to model for the non-ideal characteristics of printed transmission lines to predict the high frequency electrical performance of those structures. The methodology was validated on transmission line structures of different lengths up to 30 GHz, where a good correlation was obtained between simulation and measurement results. Furthermore, the results obtained demonstrate the significance of the paste levelling effect on the extracted DC conductivity values, and the need for accurate DC conductivity values in the modelling of printed interconnects.
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Winarski, David J. "Development of zinc oxide based flexible electronics." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1558088851479794.
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Mustonen, T. (Tero). "Inkjet printing of carbon nanotubes for electronic applications." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514293092.
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Abstract
In this thesis, preparation of carbon nanotube (CNT) inks and inkjet printing of aqueous dispersions of CNTs for certain electrical applications are studied. The nanotube inks prepared in this work are based on chemically oxidized CNTs whose polar side groups enable dispersion in polar solvents. Subsequent centrifugation and decanting processes are used to obtain stable dispersions suitable for inkjet printing. The inks are based on either carboxyl functionalized multi-walled carbon nanotubes (MWCNTs), carboxyl functionalized single wall carbon nanotubes (SWCNTs) or SWCNT-polymer composites.
The applicability of MWCNT inks is firstly demonstrated as printed patterns of tangled nanotube networks with print resolution up to ∼260 dpi and surface resistivity of ∼40 kΩ/□. which could be obtained using an ordinary inkjet office printer. In addition, MWCNT inks are found to exhibit spatial ordering in external magnetic fields due to entrapped iron catalyst nanoparticles in the inner-tubular cavity of the nanotubes. Ordering of nanotubes in the inks and in drying droplets placed in relatively weak magnetic fields (B ≤ 1 T) is demonstrated and studied.
The high electrical conductivity and optical transparency properties of SWCNTs are utilized for enhancing the conductivity of transparent poly(3,4-ethylenedioxythiophene):poly(styrenesulphonate) (PEDOT:PSS) films. Polymer-nanotube composite materials are inkjet printed on flexible substrates. It is demonstrated that incorporation of SWCNTs in the thin polymer films significantly increases the electrical conductivity of the film without losing the high transparency (> 90%). The structure of composite films is studied using atomic force microscopy (AFM).
The electronic properties of deposited random SWCNT networks are studied. The amount of deposited SWCNT is controlled by the inkjet printing technique. In dense networks the current-voltage behaviour is linear whereas for sparse films the behaviour is nonlinear. It is shown that the conduction path in dense films is through the metallic nanotubes, but in sparse films the percolation occurs through random networks of metallic and semiconducting SWCNTs having Schottky-type contacts. The existence of Schottky-junctions in the films is demonstrated with field-effect transistors (FET) on Si-chips and on polymer substrates. The latter is demonstrated as fully printed transistors using a single ink as a material source. FETs are further utilized as chemical-FET sensor applications. The performance of resistive CNT sensors and their comparisons with chem-FETs in terms of selectivity are studied for H2S gas.
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Palacios, Sebastian R. "A smart wireless integrated module (SWIM) on organic substrates using inkjet printing technology." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51906.
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This thesis investigates inkjet printing of fully-integrated modules fabricated on organic substrates as a system-level solution for ultra-low-cost and eco-friendly mass production of wireless sensor modules. Prototypes are designed and implemented in both traditional FR-4 substrate and organic substrate. The prototype on organic substrate is referred to as a Smart Wireless Integrated Module (SWIM). Parallels are drawn between FR-4 manufacturing and inkjet printing technology, and recommendations are discussed to enable the potential of inkjet printing technology. Finally, this thesis presents novel applications of SWIM technology in the area of wearable and implantable electronics. Chapter 1 serves as an introduction to inkjet printing technology on organic substrates, wireless sensor networks (WSNs), and the requirements for low-power consumption, low-cost, and eco-friendly technology. Chapter 2 discusses the design of SWIM and its implementation using traditional manufacturing techniques on FR-4 substrate. Chapter 3 presents a benchmark prototype of SWIM on paper substrate. Challenges in the manufacturing process are addressed, and solutions are proposed which suggest future areas of research in inkjet printing technology. Chapter 4 presents novel applications of SWIM technology in the areas of implantable and wearable electronics. Chapter 5 concludes the thesis by discussing the importance of this work in creating a bridge between current inkjet printing technology and its future.
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Alasmar, Rawsam. "A quantitative analysis of the value added services produced by digital color printers as perceived by print buyers /." Online version of thesis, 1996. http://hdl.handle.net/1850/11966.
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Hines, Daniel R. "Organic electronics with polymer dielectrics on plastic substrates fabricated via transfer printing." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7685.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Chemical Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Tangvichachan, Theera. "Conversion of solid ink density and dot gain specifications into colorimetric specifications /." Online version of thesis, 1993. http://hdl.handle.net/1850/11886.
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Khan, Saleem. "Towards Merging of Microfabrication and Printing of Si µ-Wires for Flexible Electronics." Doctoral thesis, Università degli studi di Trento, 2016. https://hdl.handle.net/11572/369202.
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This PhD thesis focuses on the investigation and development of a feasible technology route for fabricating multifunctional flexible electronic devices through heterogeneous integration of organic/inorganic materials on polymeric substrates. The three types of printing technologies investigated during this research include: (a) Transfer printing of inorganic semiconductors processed through standard microfabrication techniques, (b) Spray coating for deposition of organic dielectrics and metal patterns, and (c) Screen-printing of solution based transducer materials. Fabrication of electronic devices based on transfer printing of high-mobility inorganic semiconductor materials (i.e. Si), aided by high-resolution possible with microfabrication technology, was explored for high performance electronics. A cost-effective processing of printable materials is desired and therefore, through printing technologies, this thesis also explored ways to bring closer the well-established microfabrication and conventional printing tools. Due to commercial interests, the major research focus in flexible electronics thus far has been on applications such as photovoltaics and displays. However, this research is focused on active/passive electronics for sensing applications like electronic skin, which is of significant interest in robotics for safe human-robot interaction and other manipulation and exploration tasks. Optimization of the Transfer Printing for translating Si microwires from SOI (silicon on insulator) wafers on secondary flexible substrates has been investigated. Processing steps have been improved for fabrication of Si microwires on donor wafers and dry transferring them onto flexible PI (polyimide) and PET (polyethylene terephthalate) substrates. The downscaling of Si in the form of microwires and using them as building block for active devices such as field effect transistors were explored in this thesis. The microwires retain the high carrier mobility, robustness, high performance and excellent stability. Arrays of MISFETs (metal insulator field effect transistors) structures were successfully fabricated and the response variations were compared. The differently doped Si microwires were analyzed in an asymmetric metal semiconductor metal (MSM) structures under planar and bend mode conditions. The optical response as well as the thermoelectric properties of the alternately doped pn-Si microwires were also investigated.
A feasible fabrication route is presented, where combination of transfer printing for Si microwires and development of the subsequent post-processes by additive manufacturing techniques i.e. Screen-printing, Spray coating and Micro-spotting are mainly investigated. The Si microwires are employed as the semiconductor in the MISFET devices whereas screen-printed metal patterns are used for back-gate and deposition of dielectric layer is performed through spray coating. In parallel, screen-printing is also used for development of large area pressure sensor patches using two different materials i.e. P(VDF-TrFE) (Polyvinylidene Fluoride Trifluoroethylene) and nanocomposites of MWCNTs/PDMS (multiwall carbon nanotubes mixed with poly(dimethylsiloxane) for measuring dynamic and static contact events. Promising results have been achieved by developing a cost-effective way of manufacturing an all Screen-Printed flexible pressure sensors using piezoelectric transducer through P(VDF-TrFE) and piezoresistive based MWCNT/PDMS nanocomposites. Active electronic circuitry is needed for signal conditioning, amplification or processing of the sensory data on the flexible foils, which is deemed to be developed through Si microwires based technology in the next phase of the project. Ultimate goal of the PhD study was to develop a fabrication platform by combining three different printing technologies for large area sensor patches. Major challenges involved in the development of flexible device designs and printing technologies are highlighted and addressed with dependable solutions. The research concludes with proposing an innovative approach towards heterogeneous integration of large area sensory cells made of organic materials to the active devices based on inorganic semiconductors such as Si microwires. This technological platform for heterogeneous integration of devices made of diverse materials (organic, inorganic etc.) on soft substrates is believed to be a step-change needed to advance flexible electronics towards manufacturing.
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Khan, Saleem. "Towards Merging of Microfabrication and Printing of Si µ-Wires for Flexible Electronics." Doctoral thesis, University of Trento, 2016. http://eprints-phd.biblio.unitn.it/1670/1/Towards_Merging_of_Printing_Technologies_for_Flexible_Electronics_Using_Si_%C2%B5-wires.pdf.
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This PhD thesis focuses on the investigation and development of a feasible technology route for fabricating multifunctional flexible electronic devices through heterogeneous integration of organic/inorganic materials on polymeric substrates. The three types of printing technologies investigated during this research include: (a) Transfer printing of inorganic semiconductors processed through standard microfabrication techniques, (b) Spray coating for deposition of organic dielectrics and metal patterns, and (c) Screen-printing of solution based transducer materials. Fabrication of electronic devices based on transfer printing of high-mobility inorganic semiconductor materials (i.e. Si), aided by high-resolution possible with microfabrication technology, was explored for high performance electronics. A cost-effective processing of printable materials is desired and therefore, through printing technologies, this thesis also explored ways to bring closer the well-established microfabrication and conventional printing tools. Due to commercial interests, the major research focus in flexible electronics thus far has been on applications such as photovoltaics and displays. However, this research is focused on active/passive electronics for sensing applications like electronic skin, which is of significant interest in robotics for safe human-robot interaction and other manipulation and exploration tasks. Optimization of the Transfer Printing for translating Si microwires from SOI (silicon on insulator) wafers on secondary flexible substrates has been investigated. Processing steps have been improved for fabrication of Si microwires on donor wafers and dry transferring them onto flexible PI (polyimide) and PET (polyethylene terephthalate) substrates. The downscaling of Si in the form of microwires and using them as building block for active devices such as field effect transistors were explored in this thesis. The microwires retain the high carrier mobility, robustness, high performance and excellent stability. Arrays of MISFETs (metal insulator field effect transistors) structures were successfully fabricated and the response variations were compared. The differently doped Si microwires were analyzed in an asymmetric metal semiconductor metal (MSM) structures under planar and bend mode conditions. The optical response as well as the thermoelectric properties of the alternately doped pn-Si microwires were also investigated.
A feasible fabrication route is presented, where combination of transfer printing for Si microwires and development of the subsequent post-processes by additive manufacturing techniques i.e. Screen-printing, Spray coating and Micro-spotting are mainly investigated. The Si microwires are employed as the semiconductor in the MISFET devices whereas screen-printed metal patterns are used for back-gate and deposition of dielectric layer is performed through spray coating. In parallel, screen-printing is also used for development of large area pressure sensor patches using two different materials i.e. P(VDF-TrFE) (Polyvinylidene Fluoride Trifluoroethylene) and nanocomposites of MWCNTs/PDMS (multiwall carbon nanotubes mixed with poly(dimethylsiloxane) for measuring dynamic and static contact events. Promising results have been achieved by developing a cost-effective way of manufacturing an all Screen-Printed flexible pressure sensors using piezoelectric transducer through P(VDF-TrFE) and piezoresistive based MWCNT/PDMS nanocomposites. Active electronic circuitry is needed for signal conditioning, amplification or processing of the sensory data on the flexible foils, which is deemed to be developed through Si microwires based technology in the next phase of the project. Ultimate goal of the PhD study was to develop a fabrication platform by combining three different printing technologies for large area sensor patches. Major challenges involved in the development of flexible device designs and printing technologies are highlighted and addressed with dependable solutions. The research concludes with proposing an innovative approach towards heterogeneous integration of large area sensory cells made of organic materials to the active devices based on inorganic semiconductors such as Si microwires. This technological platform for heterogeneous integration of devices made of diverse materials (organic, inorganic etc.) on soft substrates is believed to be a step-change needed to advance flexible electronics towards manufacturing.
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Broman, Eva. "Printable Biosensors based on Organic Electrochemical Transistors with a Platinized Gate Electrode." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-87641.
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There is a great demand for low-cost disposable sensors in a variety of markets, such as the food chainand health care. No assay is performed more than that of glucose and approximately 85 % of the entirebiosensor market accounts for glucose biosensors. Each year, 6 billion glucose assays are performed andthe majority of them are based on electrochemical detection. Organic electrochemical transistors(OECTs) have favorable properties in terms of low operating voltages and have previously been used asbase for electrochemical detection of glucose. A low-cost disposable biosensor can be achieved by theuse of high throughput printing techniques. Up until now, no printable biosensors based on organic electrochemicaltransistors have been developed. In this thesis a printable miniaturized prototype for a glucose biosensor based on an OECT with a platinizedgate electrode has been designed, developed and evaluated. The biosensor has been functionalizedwith the enzyme glucose oxidase. Different platinum deposition techniques have been used to depositplatinum onto the printed carbon gate electrode: electrodeposition, platinum nanoparticle solutiondeposited either by inkjet printing or pipetting and thermal evaporation. The gate electrodes were characterized with cyclic voltammetry in hydrogen peroxide, ferricyanide andglucose. The characterizations revealed no significant differences between the different deposition techniques.However, with gate electrodes produced by printed carbon followed by electrodeposition ofplatinum it was possible to sense glucose in a concentration in the range of the values for diabetic persons.Thus, the electrodes are a promising option as gate electrodes in a glucose biosensor based on anOECT. The characteristics of the OECT revealed that the responses resembled a transistor.
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Forsberg, Viviane. "Liquid Exfoliation of Molybdenum Disulfide for Inkjet Printing." Licentiate thesis, Mittuniversitetet, Avdelningen för naturvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-29181.
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Since the discovery of graphene, substantial effort has been put toward the synthesis and production of 2D materials. Developing scalable methods for the production of high-quality exfoliated nanosheets has proved a significant challenge. To date, the most promising scalable method for achieving these materials is through the liquid-based exfoliation (LBE) of nanosheetsin solvents. Thin films of nanosheets in dispersion can be modified with additives to produce 2D inks for printed electronics using inkjet printing. This is the most promising method for the deposition of such materials onto any substrate on an industrial production level. Although well-developed metallic and organic printed electronic inks exist on the market, there is still a need to improve or develop new inks based on semiconductor materials such as transition metal dichalcogenides (TMDs) that are stable, have good jetting conditions and deliver good printing quality.The inertness and mechanical properties of layered materials such as molybdenum disulfide (MoS2) make them ideally suited for printed electronics and solution processing. In addition,the high electron mobility of the layered semiconductors, make them a candidate to become a high-performance semiconductor material in printed electronics. Together, these features make MoS2 a simple and robust material with good semiconducting properties that is also suitable for solution coating and printing. It is also environmentally safe.The method described in this thesis could be easily employed to exfoliate many types of 2D materials in liquids. It consists of two exfoliation steps, one based on mechanical exfoliation of the bulk powder utilizing sand paper, and the other inthe liquid dispersion, using probe sonication to liquid-exfoliate the nanosheets. The dispersions, which were prepared in surfactant solution, were decanted, and the supernatant was collected and used for printing tests performed with a Dimatix inkjetprinter. The printing test shows that it is possible to use the MoS2 dispersion as a printed electronics inkjet ink and that optimization for specific printer and substrate combinations should be performed. There should also be advances in ink development, which would improve the drop formation and break-off at the inkjet printing nozzles, the ink jetting and, consequently, the printing quality.Sedan upptäckten av grafen har mycket arbete lagts på framställning och produktion av 2D-material. En viktig uppgift har varit att ta fram skalbara metoder för produktion av högkvalitativa nanosheets via exfoliering. Den mest lovande skalbarametoden hittills har varit vätskebaserad exfoliering av nanosheets i lösningsmedel. Tunna filmer av nanosheets i dispersion kan anpassas med hjälp av tillsatser och användas för tillverkning av halvledare strukturer med inkjet-skrivare, vilket är den mest lovande metoden för på en industriell produktions nivå beläggaden typen av material på substrat. Även om det finns välutvecklade metalliska och organiskabläck för tryckt elektronik, så finns det fortfarande ett behov av att förbättra eller utveckla nya bläck baserade på halvledarmaterial som t.ex. TMD, som är stabila, har goda bestryknings egenskaper och ger bra tryckkvalitet. Den inerta naturen tillsammans med de mekaniska egenskaperna som finns hosskiktade material, som t.ex. molybdendisulfid (MoS2), gör demlämpliga för flexibel elektronik och bearbetning i lösning. Dessutom gör den höga elektronmobiliteten i dessa 2D-halvledaredem till en stark kandidat som halvledarmaterial inom trycktelektronik. Det betyder att MoS2 är ett enkelt och robust material med goda halvledaregenskaper som är lämpligt för bestrykning från lösning och tryck, och är miljömässigt säker.Den metod som beskrivs här kan med fördel användas föratt exfoliera alla typer av 2D-material i lösning. Exfolieringensker i två steg; först mekanisk exfoliering av torr bulk med sandpapper, därefter används ultraljudsbehandling i lösning för att exfoliera nanosheets. De dispersioner som framställts i lösning med surfaktanter dekanterades och det övre skiktetanvändes i trycktester med en Dimatix inkjet-skrivare.Tryckprovet visar att det är möjligt att använda MoS2 -dispersion som ett inkjet-bläck och att optimering för särskildaskrivar- och substratkombinationer borde göras, såsom förbättringav bläcksammansättningen med avseende på droppbildning och break-off vid skrivarmunstycket, vilket i sin tur skulleförbättra tryckkvaliteten.
KM2
Paper Solar Cells
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Nelo, M. (Mikko). "Inks based on inorganic nanomaterials for printed electronics applications." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526210117.
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Abstract In this thesis several novel inks based on dry inorganic powders enabling magnetic, piezoelectric and memory resistive (memristive) function were researched for printed electronics applications. Low curing temperature screen–printable magnetic inks for high frequency applications based on dry cobalt nanoparticles were developed in the first part of the work. Three publications were achieved. The first one concentrated on ink formulation and its process development, the second on the utilization of multifunctional surfactant, and the third on the development of the inks for plastic substrates. The magnetic inks developed were cured at 120 °C. The electrical performance, microstructure, surface quality and mechanical durability of printed and cured layers were investigated. Relative permeability values up to 3 and related loss tangents up to 0.01 were achieved at 2 GHz frequency, as well as a pull–off strength of up to 5.2 MPa. The maximum loading level of cobalt nanoparticles was 60 vol–%, after which the stability of the ink started to degrade. The developed ink enabled the miniaturization of a patch antenna. In the second part of the thesis, the formulation of inks based on piezoelectric ceramic particles in powder form with ferroelectric polymers as a matrix material is introduced. The performance and quality of the printed inks and cured layers were investigated. The measured pull off –strength was up to 3.25 MPa, relative permittivity was up to 48 at 1 kHz and piezoelectric constant d31 up to 17 pm/V. The printed piezoelectric layer can be utilized in a pressure sensor. In the third part of the thesis, the development of inks for a novel printed memory component, a memristor, is researched. A synthesis route was developed for an organometallic precursor solution, which was formulated into inkjet–printable form. The printing tests were carried out in order to find the most feasible layer thickness with memristive behaviour. The influence of substrate materials and different thermal treatments on the components’ electrical properties, durability of read/erase –cycles and overall lifetime were also investigated. The prepared memristive patterns remained functional for up to 35 days, while the precursor solution remained usable for over a year. The memristive areas withstood up to 30 read/erase cycles and by utilizing heat treatments the shift in resistance value increased by up to three orders of magnitudeTiivistelmä Väitöstyössä kehitettiin epäorgaanisten kuivien jauhemaisten materiaalien pohjalta magneettisia, pietsosähköisiä ja memristiivisiä musteita käytettäviksi painettavan elektroniikan sovelluksissa. Työn ensimmäisessä osassa tutkittiin korkean taajuuden sovelluksissa käytettävien magneettisten, matalassa lämpötilassa kovetettavien, jauhemaisiin kobolttinanopartikkeleihin perustuvien silkkipainomusteiden valmistamista. Tulokset on esitetty kolmessa julkaisussa, joista ensimmäinen keskittyi musteen formulointiin, toinen monifunktionaalisen surfaktantin hyödyntämiseen ja kolmas musteen kehittämiseen muovialustalle sopivaksi. Työssä kehitettiin 120 °C:ssa kovettuvia musteita, joista valmistettujen kalvojen suhteellisen permeabiliteetin maksimiarvoksi saatiin 3 ja häviöiden minimiarvoksi 0,01 kahden gigahertsin taajuudella. Pull–off –vetotestin tulokseksi saatiin jopa 5,2 MPa. Musteet säilyivät vakaina enimmillään 60 tilavuusprosentin metallipitoisuudella. Kehitettyä mustetta käytettiin tasoantennin miniatyrisoinnissa. Toisessa osassa kehitettiin pietsosähköisiä musteita, jotka pohjautuivat keraamijauheeseen ja matriisimateriaalina toimivaan ferrosähköiseen muoviin. Niistä valmistettujen kalvojen parhaaksi pull off –vetotestin tulokseksi saatiin 3,25 MPa, permittiivisyyden maksimiarvoksi 48 yhden kilohertsin taajuudella ja d31–pietsovakion maksimiarvoksi jopa 17 pm/V. Kehitettyjä painettuja rakenteita voidaan käyttää painettavissa paineantureissa. Kolmannessa osassa kehitettiin uudentyyppinen painettava muistikomponentti, memristori ja komponenttien valmistamiseksi uusi prekursoriliuoksen synteesi. Syntetisoitu liuos muokattiin mustesuihkutulostettavaksi. Painokokeiden avulla selvitettiin materiaalin paksuus, jolla saatiin aikaan muistivastukselle ominainen memristiivinen käyttäytyminen. Työssä tutkittiin substraattimateriaalien ja mahdollisten lämpökäsittelyjen vaikutusta komponenttien sähköisiin ominaisuuksiin, luku/kirjoitussyklien kestoon sekä käyttöikään. Valmistetut memristiiviset kalvot säilyivät toimivina 35 vuorokautta ja prekursoriliuos yli vuoden. Memristiiviset pinnat kestivät jopa 30 luku/kirjoitussykliä ja vastusarvon muutos saatiin lämpökäsittelyllä kolmea kertaluokkaa suuremmaksi
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Pudas, M. (Marko). "Gravure-offset printing in the manufacture of ultra-fine-line thick-films for electronics." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514273036.
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Abstract
In gravure offset printing, ink is transferred with the help of an offset material from a patterned gravure plate to a substrate. This thesis is concerned with the study and further development of this printing process for electronics; on alumina, glass and polymers.
The work has been divided into five parts. In the first section, the printing process is described. The second section describes the composition of the inks for gravure offset printing and the resulting ink properties. It also presents the ink transfer mechanism; the model that explains how the ink is transferred between an offset material and a substrate. The third chapter details the printing process explained by a solvent absorption mechanism. The forth chapter describes the firing/curing of printed samples and their properties. The last chapter describes applications of the method.
The inks used to produce conductors on ceramics (ceramic inks) and conductors on polymers (polymer inks) contain silver particles, and were under development for gravure offset printing. The major achieved properties were the high ink pickup to the offset blanket and high transfer percentage to the substrate. 100% ink transfer from blanket to substrate for ceramic inks and almost 100% ink transfer for polymer inks was obtained. The printing of ceramic inks was able to produce 8 μm of relatively thick, 300 μm wide lines with < 10 mΩ/sq. resistance. The minimum line width for conducting lines was 35 μm, with one printing. Multi printing was applied producing as many as 10 times wet-on-wet multiprinted lines with 100 % ink transfer from blanket to substrate resulting in a square resistance of 1mΩ/sq. Polymer inks were able produce a square resistance of 20 mΩ/sq. for 300 μm wide lines after curing at 140 °C for about 15 min, and the minimum width was down to 70 μm.
In the optimised manufacturing process, the delay time on the blanket was reduced to 3 s. In addition to ultra-fine-line manufacturing of conductors, the method enables the manufacture of special structures e.g. laser-solder contact pads with 28/28 μm lines/spaces resolution. With industrial printing equipment it is possible to produce 100 m2/h with the demonstrated printing properties.
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Arce, B. Enrique A. "Improving quality consistency and productivity of color separations utilizing the Dupont image manager /." Online version of thesis, 1990. http://hdl.handle.net/1850/11521.
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Schneider, Mary Lee. "A comparison of high-end color system halftones and postscript-generated halftones /." Online veresion of thesis, 1991. http://hdl.handle.net/1850/11148.
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Milburn, David L. "Using measured photography to obtain optimal results from CCD color scanners /." Online version of thesis, 1993. http://hdl.handle.net/1850/11095.
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Li, Jiantong. "Ink-jet printing of thin film transistors based on carbon nanotubes." Doctoral thesis, KTH, Integrerade komponenter och kretsar, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-24427.
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The outstanding electrical and mechanical properties of single-walled carbon nanotubes (SWCNTs) may offer solutions to realizing high-mobility and high-bendability thin-film transistors (TFTs) for the emerging flexible electronics. This thesis aims to develop low-cost ink-jet printing techniques for high-performance TFTs based on pristine SWCNTs. The main challenge of this work is to suppress the effects of “metallic SWCNT contamination” and improve the device electrical performance. To this end, this thesis entails a balance between experiments and simulations. First, TFTs with low-density SWCNTs in the channel region are fabricated by utilizing standard silicon technology. Their electrical performance is investigated in terms of throughput, transfer characteristics, dimensional scaling and dependence on electrode metals. The demonstrated insensitivity of electrical performance to the electrode metals lifts constrains on choosing metal inks for ink-jet printing. Second, Monte Carlo models on the basis of percolation theory have been established, and high-efficiency algorithms have been proposed for investigations of large-size stick systems in order to facilitate studies of TFTs with channel length up to 1000 times that of the SWCNTs. The Monte Carlo simulations have led to fundamental understanding on stick percolation, including high-precision percolation threshold, universal finite-size scaling function, and dependence of critical conductivity exponents on assignment of component resistance. They have further generated understanding of practical issues regarding heterogeneous percolation systems and the doping effects in SWCNT TFTs. Third, Monte Carlo simulations are conducted to explore new device structures for performance improvement of SWCNT TFTs. In particular, a novel device structure featuring composite SWCNT networks in the channel is predicted by the simulation and subsequently confirmed experimentally by another research group. Through Monte Carlo simulations, the compatibility of previously-proposed long-strip-channel SWCNT TFTs with ink-jet printing has also been demonstrated. Finally, relatively sophisticated ink-jet printing techniques have been developed for SWCNT TFTs with long-strip channels. This research spans from SWCNT ink formulation to device design and fabrication. SWCNT TFTs are finally ink-jet printed on both silicon wafers and flexible Kapton substrates with fairly high electrical performance.QC 20100910
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Sankir, Nurdan Demirci. "Flexible Electronics: Materials and Device Fabrication." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/30207.
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This dissertation will outline solution processable materials and fabrication techniques to manufacture flexible electronic devices from them. Conductive ink formulations and inkjet printing of gold and silver on plastic substrates were examined. Line patterning and mask printing methods were also investigated as a means of selective metal deposition on various flexible substrate materials. These solution-based manufacturing methods provided deposition of silver, gold and copper with a controlled spatial resolution and a very high electrical conductivity. All of these procedures not only reduce fabrication cost but also eliminate the time-consuming production steps to make basic electronic circuit components. Solution processable semiconductor materials and their composite films were also studied in this research. Electrically conductive, ductile, thermally and mechanically stable composite films of polyaniline and sulfonated poly (arylene ether sulfone) were introduced. A simple chemical route was followed to prepare composite films. The electrical conductivity of the films was controlled by changing the weight percent of conductive filler. Temperature dependent DC conductivity studies showed that the Mott three dimensional hopping mechanism can be used to explain the conduction mechanism in composite films. A molecular interaction between polyaniline and sulfonated poly (arylene ether sulfone) has been proven by Fourier Transform Infrared Spectroscopy and thermogravimetric analysis. Inkjet printing and line patterning methods also have been used to fabricate polymer resistors and field effect transistors on flexible substrates from poly-3-4-ethyleneoxythiophene/poly-4-sytrensulfonate. Ethylene glycol treatment enhanced the conductivity of line patterned and inkjet printed polymer thin films about 900 and 350 times, respectively. Polymer field effect transistors showed the characteristics of traditional p-type transistors. Inkjet printing technology provided the transfer of semiconductor polymer on to flexible substrates including paper, with high resolution in just seconds.Ph. D.
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Neff, Joel Emerson. "Investigation of the effects of process parameters on performance of gravure printed ITO on flexible substrates." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29625.
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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.Committee Chair: Melkote, Shreyes; Committee Co-Chair: Danyluk, Steven; Committee Member: Graham, Samuel. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Hamid, Omar Abdulhakeem. "3D printing of a gradient-patterned tubular scaffold for central nervous system regenerative applications." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/49801/.
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During the central nervous system (CNS) morphogenesis, chemical gradients of morphogens such as retinoic acid (RA) or sonic hedgehog play a central role in regulating CNS patterning and differentiation of neural subtypes. Recapitulation of these gradients in a 3D hydrogel matrix may provide a model for CNS tissue formation in vitro. 3D Printing technology offers an opportunity to reproduce the complex architecture of cell microenvironment. We have developed a 3D-printable alginate hydrogel bioink suitable for extrusion-based bioprinting. The bioink was characterised by shear thinning, high printing resolution and minimal adverse effects on cell viability. The bioink was successfully used to print mouse embryonic stem cells (mESCs)-laden constructs and supported their differentiation into neural-like cells. Extrusion-based bioprinting was used to 3D-print hybrid polycaprolactone (PCL)-alginate tubular scaffolds functionalised with a fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) concentration gradient pattern. Quantification of the FITC-BSA concentrations in the scaffold showed a linear reduction in concentration as a function of scaffold’s distance (length). Tubular scaffolds printed with fibroblast-laden alginate supported cell viability and proliferation up to 6 days after printing. Next, the developed model was used to replicate the in vivo RA-induced directed differentiation of mESCs into spinal cord neurons. RA-concentration-dependent acquisition of neural identity was investigated using immunocytochemistry and flow cytometry analysis. RA promoted the formation of neurons with hindbrain and spinal cord identity and supressed the forebrain identity in a concentration-dependent manner. Among the investigated hydrogels, gelatine methacrylate (GelMA) supported neural differentiation and neurite outgrowth of the mESCs-derived embryoid bodies (EBs). Subsequently EBs-laden GelMA (5%) was successfully used as a bioink to print the hybrid PCL-hydrogel scaffolds. 3D Printing of EBs and RA-loaded GelMA in PCL scaffold induced differentiation of EBs into neurons with spinal cord positional identity. In conclusion, the model can be used for effective morphogens gradients delivery to replicate some of the complex processes of CNS development in vitro.
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Oja, Thomas Edward. "Characterization of the Integration of Additively Manufactured All-Aromatic Polyimide and Conductive Direct-Write Silver Inks." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101036.
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Hybridizing additive manufacturing (AM) structures and direct write (DW) deposition of conductive traces enables the design and physical creation of integrated, complex, and conformal electronics such as embedded electronics and complex routing on a fully AM structure. Although this hybridization has a promising outlook, there are several key AM substrate-related limitations that limit the final performance of these hybridized AM-DW electronic parts. These limitations include low-temperature processability (leading to high trace resistivity) and poor surface finish (leading to electronic shorts and disconnections). Recently discovered ultraviolet-assisted direct ink write (UV-DIW) all-aromatic polyimide (PI) provides an opportunity to address these previous shortcomings previously due to its high-temperature stability (450C) and superior surface finish (relative to other AM processes).
The primary goal of this thesis is to characterize the integration of this UV-DIW PI with DW-printed conductive inks as a means for obtaining high-performance hybrid AM-DW electronics. This goal has been achieved through an investigation into the increased temperature stability of AM PI on the conductivity and adhesion of DW extrusion and aerosol jet (AJ) silver inks, determining the dielectric constant and dissipation factor of processed UV-DIW PI, and determining the achievable microwave application performance of UV-DIW PI. These performance measurements are compared to commercially-available PI film and relative to existing AM substrates, such as ULTEM 1010.
The temperature stability of UV-DIW PI enabled higher-temperature post-processing for the printed silver traces, which decreased DIW trace resistivity from 14.94±0.55 times the value of bulk silver at 160 °C to 2.16±0.028 times the resistivity of bulk silver at 375 °C, and AJ silver trace resistivity from 5.27±0.013 times the resistivity of bulk silver at 200 °C to 1.95±0.15 times the resistivity of bulk silver at 350 °C. The adhesion of these traces was not negatively affected by higher processing temperatures, and the traces performed similarly on UV-DIW PI and commercial PI. Furthermore, at similar thicknesses, UV-DIW PI was found to have a similar dielectric constant and dissipation factor to commercial Dupont Kapton PI film from 1 kHz to 1 MHz, indicating its ability to perform highly as a dielectric electronics substrate. Finally, the decrease in resistivity was able to decrease the gap in microwave stripline transmission line performance when compared with ULTEM 1010 processed at 200°C, with peak 10 GHz S21 loss differences decreasing from 2.46 dB to 1.32 dB after increasing the UV-DIW processing temperature from 200 °C to 400°C.Master of Science
Due to the extensive potential benefits and applications, researchers are looking to hybridize additive manufacturing (AM) processes with direct write (DW) techniques to directly print a 3D part with integrated electronics. Unfortunately, there are several key substrate-related limitations that hinder the overall performance of a part fabricated by hybrid AM-DW processes. Specifically, typical AM materials are not capable of providing an electronics substrate with combined sufficient surface resolution, surface finish, and high-temperature processing stability. However, the recent discovery of a novel AM-processable all-aromatic polyimide (PI) presents an opportunity for addressing these limitations as its printed form offers a high surface resolution, superior surface finish, and mechanical stability up to 400 °C. The primary goal of this thesis is to evaluate the benefits and drawbacks of this PI, processed via ultraviolet-assisted direct ink write (UV-DIW) AM, as an AM-DW electronics substrate. Specifically, the author characterized the effect of the increased temperature stability of the printed PI on the resultant conductivity and adhesion of silver inks printed via direct ink write (DIW) and aerosol jetting (AJ) DW processes. These results were also compared to the performance of the inks on commercial PI. Furthermore, the dielectric performance of printed PI was evaluated and compared to commercial PI. To demonstrate and evaluate the hybridized approach in a potential end-use application, the author also characterized the achievable microwave application performance of UV-DIW polyimide relative to the existing highest performance commercially available printed substrate material. The experiments in this thesis found an 83% and 66% decrease in resistivity from extrusion and AJ printed inks due to the ability of the printed PI to be processed at higher temperatures. Furthermore, UV-DIW PI was found to have similar dielectric properties to commercial PI film, which indicates that it can serve as a high-performance dielectric substrate. Finally, the high-temperature processing stability was able to decrease the performance gap in microwave application performance between the higher performing dielectric substrate, ULTEM 1010. These results show that UV-DIW could serve as a dielectric substrate for hybridized AM-DW electronic parts with higher performance and the ability to be deployed in harsher environments than previous AM-DW electronic parts explored in literature.
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Palmer, Carl M. "A calibration study of a still video system and photomatic color separation program /." Online version of thesis, 1989. http://hdl.handle.net/1850/11538.
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Knott, Andrew N. "3D printing of light trapping structures for dye-sensitised solar cells." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50058/.
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Converting solar energy directly into electricity as a clean and renewable energy resource is immensely important to solve the energy crisis and environmental pollution problems induced by the consumption of fossil fuels. Dye-sensitised solar cells have attracted a great deal of attention following their development in 1991. They provide a technically and economically credible alternative that could challenge the dominance of conventional p-n junction photovoltaic devices in the solar energy market. 3D printing and other additive manufacturing techniques allow the fabrication of geometrically complex end-use products and components in a variety of materials by using technologies that deposit material layer-by-layer. The additive manufacturing of optoelectronic devices is still in its infancy but has the potential to completely revolutionise the industry. Two-photon polymerisation is a technique used to fabricate 3D structures with resolutions down to a few hundred nanometres. The technique shows the ability to fabricate highly complex 3D structures of arbitrary shape with unprecedented levels of control. In this thesis the two-photon polymerisation 3D printing technique is used to fabricate TiO2 thin films of optimised 3D micro-design for use in DSSCs. Our 3D printed films have a considerable advantage over the conventional (random assembly) films, as they allow the implementation of optimised light trapping designs directly into the cell. Cells are characterised with scanning photocurrent microscopy with results showing these light trapping structures are able to improve photocurrent generation by up to approximately sim 9%$ when compared to conventional random assembly TiO2.
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Engman, Alexander. "Development and 3D Printing of Intrinsically Stretchable Materials for Microsupercapacitors." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284517.
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The purpose of this thesis is to develop a simple Direct Ink Writing (DIW) method for fabricating intrinsically stretchable microsupercapacitors as ef- fective on-chip energy storage devices for the emerging stretchable electron- ics. Using the printing method for fabricating intrinsically stretchable elec- tronic components remains a novel approach. In this thesis, interdigitated structures of intrinsically stretchable electrodes were printed on a stretchable thermoplastic polyurethane (TPU) substrate using a formulated ink based on Poly(3,4-ethylenedioxythiophene):Polystyrene Sulfonate. Formulated elec- trolytes based on Poly(4-styrene Sulfonic Acid) and Phosphoric Acid were applied to the electrodes to complete the fabrication of microsupercapacitors. Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Elec- trochemical Impedance Spectroscopy (EIS) were used to characterize the per- formance of the devices. The stretchability of the electrodes was also mea- sured. Results from CV-measurements revealed a maximum capacitance of740 µF cm−2 at a scan rate of 5 mV s−1. GCD-measurements showed a capaci- tance of 952 µF cm−2 for the same device and an equivalent series resistance of approximately 7 kΩ. The printed electrodes exhibited a stretchability of 80%. The results show the feasibility of fabricating intrinsically stretchable energystorage devices using commercially available materials and a simple 3D print- ing technique. This method could be used as a high-throughput and low-cost method for stretchable electronics applications.Syftet med detta arbete är att utveckla en simpel Direct Ink Writing (DIW) metod för framställning av intrinsiskt sträckbara mikrosuperkondensatorer som effektiva on-chip energilagrinsenheter i kommande sträckbar elektronik. Användandet av DIW för att tillverka intrinsiskt sträckbara elektroniska kom- ponenter är ett nytt tillvägagångssätt. I detta arbete trycktes interdigiterade strukturer av intrinsiskt sträckbara elektroder på ett sträckbart termoplastiskt polyuretan (TPU) substrat genom att använda ett formulerat bläck baserat på Poly(3,4-etylendioxitiofen):Polystyren Sulfonat (PEDOT:PSS). Formuler- ade elektrolyter baserade på Poly(4-styrensulfonsyra) och Fosforsyra applicer- ades på elektroderna för att färdigställa tillverkningen av mikrosuperkonden- satorer. Cyklisk Voltammetri (CV), Galvanostatisk uppladdning-urladdning (eng. GCD) och Elektrokemisk Impedansspektroskopi (EIS) användes för att karaktärisera enheternas prestanda. Bläckets sträckbarhet uppmättes också. Resultaten från CV-mätningar visade att den maximala kapacitansen var 742µF cm−2 vid skanningsfrekvensen 5 mV s−1. Kapacitansen från GCD-mätningar var 952 µF cm−2 för samma enhet och den ekvivalenta serieresistansen var cirka 7 kΩ. Sträckbarheten som de tryckta elektroderna uppvisade var 80%. . Re- sultaten påvisar möjligheten att kunna framställa intrinsiskt sträckbara en-ergilagringsenheter genom att använda kommersiellt tillgängliga material och en simpel metod för friformsframställning. Denna metod skulle kunna använ- das för att framställa sträckbara elektroniska komponenter till låg kostnad och med hög produktionstakt.
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Manuelli, Alessandro. "Influences of Printing Techniques on the Electrical Performances of Conjugated Polymers for Organic Transistors." Doctoral thesis, Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200700044.
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The discovery of conducting and semiconducting polymers has opened the possibility to produce
integrated circuits entirely of plastic with standard continuous printing techniques. Nowadays
several of this polymers are commercial available, however the performances of this materials are
strongly affected by their supramolecular order achieved after deposition. In this research, the
influence of some standard printing techniques on the electrical performances of conjugated
polymers is evidenced in order to realise logic devices with these materials.
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Marks, Antony Edward. "Characterisation of lead-free solder pastes and their correlation with the stencil printing process performance." Thesis, University of Greenwich, 2012. http://gala.gre.ac.uk/9456/.
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Solder pastes are complex materials whose properties are governed by many factors. Variations exhibited in solder paste characteristics make it increasingly difficult to understand the correlations between solder paste properties and their printing process performance. The recent EU directives on RoHS (Restriction of Hazardous Substances – enacted by UK regulations) and WEEE (Waste from Electrical and Electronic Equipment) has led to the use of lead-free soldering in the SMA (surface mount assembly) process, and an urgent need for better understanding of the characteristics and printing performance of new solder paste formulations. Equally, as the miniaturisation of hand-held and consumer electronic products continues apace, the solder paste printing process remains a real challenge to the electronics assembly industry. This is because the successful assembly of electronic devices at the ultra-fine pitch and flip-chip geometry requires the deposition of small and consistent paste deposits from pad to pad and from board to board. The paste printing process at this chip-scale geometry depends on conditions such as good paste roll, complete aperture filling and paste release from the apertures onto the substrate pads. This means that the paste flow and deformation behaviour, i.e. the paste rheology, is very important in defining the printing performance of any solder paste. Rheological measurements can be used as a tool to study the deformation or flow experienced by the pastes during the stencil printing process. In addition, the rheological measurements can also be used as a quality control tool in the paste production process for identifying batch-to-batch variation, and to reduce the associated printing defects in the paste printing process. The work reported here on the characterisation of lead-free solder pastes and their correlation with the stencil printing process is divided into five main parts. The first part concerns the study of the effect of variations in flux and particle size distribution (PSD) on the creep recovery performance of lead-free solder pastes used for flip-chip assembly. For this study, a novel technique was calculating the extent of paste recovery and hence characterising the slumping tendency in solder pastes. The second part of the study concerns the influence of long-term ageing on the rheology and print quality of lead-free solder pastes used for flip-chip assembly, and the main focus of the work was to develop methodologies for benchmarking new formulations in terms of shelf life, rheological deterioration and print performance. The third part of the work deals with a rheological simulation study of the effect of variation in applied temperature on the slumping behaviour of lead-free solder pastes, and the fourth part considers the rheological correlation between print performance and abandon time for lead-free solder paste used for flip-chip assembly. The final part of the study concerns the influence of applied stress, application time and recurrence on the rheological creep recovery behaviour of lead-free solder pastes. The research work was funded through the PRIME Faraday EPSRC CASE Studentship grant, and was carried out in collaboration with Henkel Technologies, Hemel Hempstead, UK. The extensive set of results from the experimental programme, in particular relating to the aspect of key paste performance indicators, has been adapted by the industrial partner for implementation as part of a quality assurance (QA) tool in its production plant, and the results have also been disseminated widely through journal publications and presentations at international conferences.
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Kim, Sangkil. "Inkjet-printed sensors and via-enabled structures for low-cost autonomous wireless platforms." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52979.
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Fundamental research to implement the printed autonomous wireless sensor platform is studied in three aspects: fabrication method, material selection, and novel applications for autonomous sensing/communication. Additive fabrication processes, such as inkjet printing technology and electroless electroplating, are discussed and the additively created metal layers are characterized. Fundamentals for material characterization utilizing resonators are presented and electrical properties of flexible low-cost substrates like synthetic Teslin paper and Poly(methyl methacrylate) (PMMA) are characterized. Widely used flexible substrates for printing, such as Liquid Crystal Polymer (LCP) and Kapton (polyimide), are summarized and tabulated as well. Novel antenna-based applications for efficient and autonomous operation of wireless sensor system, such as an antenna on Artificial Magnetic Conductor (AMC) for wearable applications, an active beacon oscillator for Wireless Power Transfer (WPT), and a multiband RF energy harvester, are designed and their performances are experimentally verified. The printed RFID-enabled sensor topologies with/without RFID chip are discussed as a new sensor platform for autonomous wireless operation. Fully inkjet-printed via topology for system miniaturization and integration is proposed for the first time. Challenges, circuit modeling and experimental data are presented. Future and remaining work to implement the novel low-cost autonomous wireless sensor platform are also discussed.
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Zellers, Brian Andrew. "3D Printed Wearable Electronic Sensors with Microfluidics." Youngstown State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1575874880525156.
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Hamad, Aamir Hamed. "Additive Manufacturing Techniques to Enhance the Performance of Electronics Created on Flexible andRigid Substrates." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1598253714624332.
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Morais, Rogério Miranda. "Desenvolvimento de transístores para a eletrônica impressa /." Presidente Prudente, 2020. http://hdl.handle.net/11449/192597.
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Orientador: Neri AlvesResumo: Nesta tese de doutorado são apresentados resultados a respeito da fabricação e caracterização de dois tipos de transístores com eletrólito no gate (EGTs, do inglês Electrolyte Gated Transistors): Transístores eletroquímicos orgânicos (OECTs, do inglês Organic Electrochemical Transistors) e transístores de dupla camada elétrica (EDLTs, do inglês Electric Double Layer Transistor). Os dispositivos foram produzidos utilizando inkjet printing e screen printing para imprimir soluções à base de polímeros como o poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), precursores de óxido de zinco e de nanopartículas de óxido zinco. Como eletrólito de gate foram utilizadas faixas auto sustentáveis de íon gel à base de celulose. Esse último foi desenvolvido por pesquisadores do CEMOP/CENIMAT e combina a alta mobilidade iônica dos eletrólitos líquidos com a plasticidade dos eletrólitos sólidos. Sua estrutura em gel possibilita que o material seja moldado ou cortado de acordo com a aplicação. Os ECTs foram fabricados em arquitetura planar sobre substrato de vidro ou de papel, onde foram impressos: PEDOT:PSS como semicondutor e carbono como eletrodos. Os resultados mostram uma forte dependência de parâmetros como: corrente no estado ligado (Ion), no estado desligado (Ioff), transcondutância, razão Ion/Ioff, morfologia da superfície do substrato e a rugosidade. Os EDLTs foram fabricados usando síntese de auto combustão e foto-ativação química para produzir dispositivos com baix... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: On this doctoral thesis is presented results of the manufacture and characterization of two types of Electrolyte-gated Transistors (EGTs): Organic Electrochemical Transistors (OECTs) and electric double-layer transistors (EDLTs). Devices were manufactured using inkjet printing and screen printing to print solutions based on polymers such as poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS), zinc oxide precursors and zinc oxide nanoparticles. Self-sustainable bands of cellulose-based ion gel were used as gate electrolyte. The last was developed by researchers from CEMOP/CENIMAT and combines the high ion mobility of liquid electrolytes with the plasticity of solid electrolytes. This gel structure allows this material to be shaped or cut according to the application. The ECTs were manufactured in planar architecture over glass or paper substrates, where they were printed: PEDOT: PSS as semiconductor and carbon as electrodes. The results presents a strong dependence on parameters such as: on-state current (Ion), off-state current (Ioff), transconductance, Ion/Ioff ratio, surface morphology of the substrate and roughness. The EDLTs were manufactured using auto-combustion synthesis and chemical photo-activation process to produce devices with low processing temperatures in a way to be used in flexible, plastic or paper substrates. These devices are based on nanoparticles of zinc oxide as a semiconductor channel, fully printed and with heat treatment below 200 oC.... (Complete abstract click electronic access below)
Doutor
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Horn, Jacqueline Marie. "Design of a Wearable Flexible Resonant Body Temperature Sensor with Inkjet-Printing." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703340/.
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A wearable body temperature sensor would allow for early detection of fever or infection, as well as frequent and accurate hassle-free recording. This thesis explores the design of a body-temperature-sensing device inkjet-printed on a flexible substrate. All structures were first modeled by first-principles, theoretical calculations, and then simulated in HFSS. A variety of planar square inductor geometries were studied before selecting an optimal design. The designs were fabricated using multiple techniques and compared to the simulation results. It was determined that inductance must be carefully measured and documented to ensure good functionality. The same is true for parallel-plate and interdigitated capacitors. While inductance remains relatively constant with temperature, the capacitance of the device with a temperature-sensitive dielectric layer will result in a shift in the resonant frequency as environmental or ambient temperature changes. This resonant frequency can be wirelessly detected, with no battery required for the sensing device, from which the temperature can be deduced. From this work, the optimized version of the design comprises of conductive silver in with a temperature-sensitive graphene oxide layer, intended for inkjet-printing on flexible polyimide substrates. Graphene oxide demonstrates a high dielectric permittivity with good sensing capabilities and high accuracy. This work pushes the state-of-the-art in applying these novel materials and techniques to enable flexible body temperature sensors for future biomedical applications.
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Schneider, Monica [Verfasser]. "Novel concept for the formulation of printing pastes for printable electronics based on the capillary suspension phenomenon / Monica Schneider." Karlsruhe : KIT-Bibliothek, 2017. http://d-nb.info/1133020542/34.
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Agusil, Antonoff Juan Pablo. "Fabrication of (bio)molecular patterns with contact printing techniques." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/297711.
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Patterns are a collection of forming units predictably repeated over a defined magnitude. Researchers have used patterns to guarantee the functionality and repeatability of their study. For that, the obtained data is purposely compared over and over in hope that the results are comparable. Two main research approaches are based on patterns: The initial requires a single substrate with localized and repeated units to create multiple testing sites, obtaining a repeated, multi-analysis system. The second approach uses fixed localization with different testing motifs, creating a diverse multi-analysis platform. The miniaturization of these assays provides an alternative to reduce cost, maximize efficiency, and increase repeatability. Micropatterns consist on immobilized (bio)molecular motifs constrained in small areas over a solid substrate. These fixed spots provide up to thousands of reaction sites for parallel detection. Micropatterns were first developed to study the interaction between Deoxyribonucleic acid (DNA) strands and the study of the genome. Afterwards, this technology was used to create miniaturized protein patterns. Today, this technology is essential for large-scale and high-throughput biological and biochemical studies. Single-feature microarrays are routinely reproduced at many laboratories using various contact, non-contact, or alternatively methods. The foundation is to transfer a (bio)molecule in a solution onto a solid substrate obtaining a defined feature shape. This Thesis aims to expand the current contact replication techniques for microarray fabrication. Initially, an automatized microcontact printing tool was characterized to create complex patterns on a wide range of substrates. Thiols, silanes, and various biomolecules were printed on glass, silicon oxide or gold. The printing properties were explored to create a definitive protocol for further applications. The effect of the printing force and dwell time were thoroughly studied to form a mathematical expression to understand all the variables involved during contact printing. The miniscule resolution provided by the automatized tool allowed the creation of complex micropatterns with single or multiple printings steps. This tool was later upgraded and fitted with new controllers to create smaller patterns. An alternatively contact printing technique called polymer pen lithography was used to pattern the surface of specialized substrates to create micropatterns on constricted areas. The miniaturized microarrays were later liberated to create functionalized microparticles. These microparticles can be tuned for many biochemical applications, such as protein interaction studies, drug discovery or life science. Lastly, a new contact replication method was established to fabricate DNA arrays. An initial DNA master arrays was fabricated with known contact printing techniques. Then, either hybridized or in situ synthesized strands were transported to an intermediate substrate. A second hybridization or synthesis was used to transport a replica of the master array to a new substrate, maintaining the chemical and spatial information present on the original array.Un patrón es una colección de unidades formadoras que se repiten predeciblemente en una magnitud definida. Los investigadores han utilizado patrones para garantizar la funcionalidad y repetitividad de sus estudios. Para conseguir eso, los datos obtenidos de los estudios se comparan entre varios resultados, esperando así una correlación. Dos métodos de investigación están basados en patrones: uno requiere un sustrato con unidades repetidas localizadas en un plano cartesiano definido, obteniendo una plataforma de análisis múltiple. El segundo método utiliza localizaciones definidas con diferentes áreas de prueba, creando así una plataforma de multianálisis. La miniaturización de estas pruebas permiten reducir el costo, maximizar la eficiencia e incrementar la repetitividad de los ensayos. Los micropatrones consisten en puntos de (bio)moléculas limitados en pequeñas áreas para crear zonas de reacción múltiples. Esta tecnología fue inicialmente utilizada para crear las interacciones del ADN para estudios genómicos. La técnica evolucionó para crear patrones de proteínas y actualmente se utiliza para estudios bioquímicos a gran escala y de muy alto rendimiento. Patrones de una (bio)molécula repetida a través del sustrato son fabricados rutinariamente en muchos laboratorios utilizando técnicas de impresión por contacto, por inyección u otro métodos. El cimiento de estas técnicas es transferir una (bio)molécula de una solución a un sustrato. Esta Tesis pretende expandir los métodos de creación de micropatrones por técnicas de impresión por contacto. Inicialmente se caracterizó una máquina automatizada de impresión por microcontacto para crear patrones y estudiar las variables que afectan al momento de la impresión. Se correlacionaron la presión y el tiempo de impresión para entender la morfología del patrón resultante. Igualmente se caracterizó el posicionamiento micrométrico de los patrones para crear estructuras complejas. Posteriormente, la máquina se modificó para incluir la técnica de impresión con plumas poliméricas. Esta técnica permitió crear micropatrones en superficies minúsculas. Estos micropatrones fueron luego liberados para crear micropartículas que pueden ser personalizadas para aplicaciones diversas. Finalmente, se formuló una nueva técnica de replicación de patrones de ADN desde un patrón inicial, manteniendo la información química y espacial presente en éste.
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Mohan, Karuniya. "Ensemble Modelling of in situ Feature Variables for Printed Electronics Manufacturing with in situ Process Control Potential." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/84947.
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Aerosol Jet® Printing (AJP) is a direct-write based additive manufacturing process that is capable of printing electronics with fine features and various materials. It eliminates the complex masking process in traditional semiconductor manufacturing, thus enables flexible electronics design and reduces manufacturing cost. However, the quality control of AJP processes is still a challenging problem, primarily due to the lack of understanding of the potential root causes of the quality issues. There is a complex interaction among process setting variables, in situ feature variables, and quality variables in AJP processes. In this research, an ensemble model strategy is proposed to quantify the effect of the process setting variables on the in situ feature variables, and the effect of the in situ feature variables on quality variables in a two-level hierarchical way. By identifying significant in situ feature variables as responses for the process setting variables, as well as predictors for product quality in a joint estimation problem, the proposed models have a hierarchical variable relationship to enable in situ process control for variation reduction and defect mitigation. A real case study is investigated to demonstrate the advantages of the proposed method.Master of Science
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Sopeña, i. Martínez Pol. "Laser-induced forward transfer for printed electronics applications." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670919.
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Printed electronics appeared in the 1980s as a cost-effective alternative to silicon-based electronics. Employing the techniques from the graphics industry, such as rotogravure or screen printing, it was possible to print metals, ceramics, and polymers on a wide variety of materials, including flexible and organic substrates. However, these techniques became not adequate when customization or short runs were considered since the production costs of the components and devices substantially increased. To overcome these issues, direct-write techniques, such as inkjet printing, allowed depositing materials on-demand in a digital fashion. Nonetheless, the ink was ejected in the form of droplets from a nozzle, which small diameter limited the range of printable inks; only those with low viscosity (few mPa·s) and small particle size (~100 nm) could be routinely printed without resulting in nozzle clogging. Alternatively, laser-induced forward transfer (LIFT), another digital technique, has barely any of these constraints.
LIFT is a printing technique capable of depositing almost every kind of ink in a digital fashion independently of its rheology. In LIFT, a thin layer of ink is extended on a transparent donor substrate, which is placed facing the receiver substrate through a certain gap. Using a laser pulse focused on the ink donor film, a cavitation bubble is induced. The high pressure within results in its expansion, propelling the material forward towards the receiver, where it is finally deposited. Since the ink is not ejected from an output nozzle, the range of printable viscosities extends from a few mPa·s to hundreds of Pa·s, and the particles in suspension can feature sizes of up to tens of micrometers, non-achievable with other direct-write techniques. Furthermore, both the resolution of the printed features and the printing speeds are similar to those of other digital printing techniques.
In this thesis, the use of LIFT is investigated with the aim of printing inks for printed electronics applications. Special attention is devoted to the transfer of conductive pads to be used as interconnects. To demonstrate the potential and possibilities of LIFT, different inks used in printed electronics applications are chosen. These inks exhibit diverse rheologies: from low to high viscosity, and with particle sizes ranging from nano- to micrometers, characteristics that make them unprintable with most of the other direct-write methods. Finally, to prove the versatility and compatibility of the technique with the desired applications, several functional components and devices are entirely printed with LIFT.
The work is divided in three main sections. The first aims at the production of transparent electrodes by means of the LIFT of two silver nanowire inks on rigid and flexible substrates. The main laser parameters are varied to find the optimum compromise between the optical and electrical properties, to finally print a device consisting of conductive and transparent electrodes. The second focuses on the LIFT of high solid content silver screen printing ink. The study is divided in the fundamental study of the deposits and its correlation with the transfer dynamics, and the ability to obtain conductive interconnects on non-planarized regular paper. As a proof-of-concept, a radio-frequency inductor is printed on paper. The third consists of performing LIFT using continuous-wave laser sources for printing inks, with the aim of reducing the capital investment associated to pulsed LIFT. The laser parameters are varied to determine the optimum printing conditions and the transfer mechanism is investigated. As a final remark, a gas and temperature sensor is printed using this approach.
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Teichler, Anke [Verfasser], Ulrich Sigmar [Akademischer Betreuer] Schubert, and Reinhard R. [Akademischer Betreuer] Baumann. "Combinatorial screening of functional polymers for organic electronics via inkjet printing / Anke Teichler. Gutachter: Ulrich Sigmar Schubert ; Reinhard R. Baumann." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2014. http://d-nb.info/104804730X/34.
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Santos, Franceska Anna. "Phase Behavior and Rheology of Latex, Thickener, Surfactant Mixtures and Liquid Crystal Based Compositions for Printing High-Efficiency Flexible Electronics." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1151.
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This project consists of two parts. One area of focus in the first part is understanding the interactions between a non-ionic, block copolymer type dispersant and hydrophobically-modified, ethoxylated urethane (HEUR) associative thickeners in water. The dispersant was mixed at various concentrations (0-2% by weight) with HEUR thickeners at 1% by weight concentration in the aqueous medium. This study is an integral part of our attempts to determine mechanisms of viscosity drop when colorant dispersions are added to latex tint base formulations thickened with associative thickeners. One of the HEUR thickeners is a product that has been available for over three decades (HEUR RM-825), whereas the other, HEUR RM-995 is a product recently introduced to minimize the tint base viscosity drop. The old HEUR showed a definitive viscosity maximum as a function of the dispersant concentration. However, the new generation product did not indicate a viscosity maximum within the dispersant concentration range studied; instead it showed a small, but linear increase in viscosity as dispersant level was increased.
The next area of focus was on understanding the phase behavior, rheology, and interactions between polymer latex particles and a hydrophobically-modified, ethoxylated urethane (HEUR) associative thickener in water. The influence of the addition of surfactant in some of the systems was also studied. Several types of dispersions were made using two types of polymer latex, two associative thickeners, and two surfactants. Mixtures containing a small particle size acrylic latex and HEUR RM-825 exhibited the most interesting and complex phase behavior and rheology. In experiments wherein the latex particle volume fraction was kept constant, the addition of HEUR caused stable, followed by phase separated (syneresis) and stable mixtures as HEUR concentration was increased. The observed phase behavior is consistent with previous work reported by other investigators. However, detailed rheological data on systems such as these have not been reported, and this report presents the rheological data and correlate rheology with the phase behavior. The stable latex-HEUR mixtures at low HEUR levels show shear-thinning viscosity with well-defined low-shear Newtonian plateaus. As HEUR level is increased wherein syneresis is observed, erratic rheological profiles with shear-thickening are observed. When HEUR level is increased to a region where no syneresis is observed, low shear Newtonian plateaus re-appeared albeit at higher viscosities. The effects of added non-ionic and anionic surfactants on the dispersion are also studied.
The main focus of the second part of this project is hybrid organic-inorganic photovoltaics. They have been the focus of recent studies due to their promising use in low-cost, flexible electronics, which can be processed from solution by printing and coating techniques. Understanding the rheology of these nanocomposites is essential in controlling shear flows during printing and application processes. Through rheology, we can determine different properties of poly(3-hexylthiophene) and dodecanethiol (DDT) modified zinc oxide (ZnO-DDT). Semiconductor nanowires such as ZnO have rigid or rod-like macromolecule geometry. Therefore, they have a tendency to have a lytropic liquid crystal (LLC) phase. LLC orders occur spontaneously in solutions with rod-shaped or anistropic objects from isotropic phase to nematic phase above a critical volume fraction which was studied using ZnO-DDT. The shear-induced alignment of the liquid crystal molecules was analyzed, serving as a guide for LLC printing. Furthermore by using this nanocomposite we are able to induced gelation using the ZnO-DDT nanowires in what is considered as a “good solvent,” dichlorobenzene. The kinetics of this gelation process was determined to be of first-order reaction kinetics. Furthermore, a mechanism of this gelation process is also presented.
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Salas, Barenys Arnau. "Full-3D Printed Electronics Fabrication of Radiofrequency Circuits and Passive Components." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/673257.
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This doctoral thesis raises the idea that 3D printing can change the paradigm of radio- frequency electronics, which has been traditionally developed mainly conceiving planar topologies. A review on additive manufacturing and the different existing technologies is reported. To focus on the concerning topic, several applications of 3D-printed electronics in the RF field are collected to elaborate the State-of-the-Art. The main objectives of this project is to develop a 3D manufacturing technology for RF electronics passive components and circuits and to generate innovative research about the possibilities of AM in this area.
Once the context is exposed, the manufacturing process for 3D-printed electronics developed within the frame of this project is described and characterized. This technology consists of three different steps. First of all, the 3D model of the prototype is designed using a CAD environment with electromagnetic simulation features, hence size parameters are adjusted to fit the specifications. Hereon, the 3D polymer substrate is printed by using either stereolithography or material jetting techniques. Stereolithography is found to be a cheaper AM technology while material jetting offers a better printing resolution and softer surface endings. Finally the object is partially metallized to obtain the conductive layer of the component or circuit using an electrolytic process, such as electroless plating or electroplating. The characterization includes the electromagnetic specifications of the dielectric substrates (i.e. the dielectric constant and the loss tangent) and the quality of the metallization (i.e. the resistivity and the layer thickness). The results of the plating resitivity are found to be competitive compared to the SoA.
In order to demonstrate the possibilities of the developed technology, several devices are designed and tested. The key factor of these prototypes is that they would be very difficult, costly or impossible to manufacture using conventional technologies. As a preliminary demonstration, a hello-world circuit to turn on a LED proves that almost any kind of shape can be plated, including vias; both through hole and SMD components can be soldered and that mechanical stress such as USB plugging is resisted by the metal layer. In addition, a study on conical inductors is carried out showing the advantages of these components for broadband applications with compact devices. They offer a larger bandwidth cylindrical solenoids and are more compact than planar coils. As an application example, they are used in the manufacturing of 3D passive filters. The prototypes present agreement with simulations and the ideal response. Slight discrepancies are caused by the manufacturing tolerances. Moreover, 3D filters are also designed as one single-printed part, a new technique for 3D discrete component integration. That permits to reduce the number of components to assembly so that it does not increase with the order of the filter. These single 3D-printed prototypes present improvement in performance and compactness as well.
In addition to the lumped circuits, a whole chapter is dedicated to distributed-element devices. A study on helical-microstrip transmission lines is carried out showing an important enhancement for line segment miniaturization. Hereon, they are implemented on the design of impedance transformers, which also benefit from bandwidth broadening. Another proposed device is the hybrid branch-line coupler, which, besides the implementation of helical lines, it has been designed conceiving a capacitively loaded folded structure. This coupler gives very interesting results in compactness improvement, without significant reduction of the bandwidth. The prototypes have been compared to the conventional topology as well as to other designs found within the SoA. Finally, helical-microstrip coupled-line couplers have also been designed, fabricated and studied. They offer a good enhancement in terms of compactness though it goes in slight detriment of the coupling factor due to the manufacturing tolerances.Aquesta tesi doctoral proposa la idea que la impressió 3D pot canviar el paradigma de l’electrònica de radiofreqüència. S’hi anomenen i expliquen les tecnologies de manufactura additiva existents. Per centrar-se en el principal tema d’interès, s’exposa un compendi d’aplicacions d’electrònica impresa en 3D en el camp de la RF amb el qual s’ha confeccionat l’estat de la qüestió. Un cop exposat el context, el procés de manufactura per a electrònica impresa en 3D que s’ha desenvolupat en el marc d’aquest projecte és descrit i caracteritzat. Aquesta tecnologia consisteix en la impressió en 3D d’un substrat de polímer utilitzant tècniques basades, o bé en estereolitografia, o bé en material jetting. Posteriorment, el component o circuit es metal·litza parcialment mitjançant un procés electrolític ja sigui electroless plating o electroplating. La caracterització inclou les especificacions electromagnètiques del substrat dielèctric i la qualitat de metal·lització, que s’han resultat ser competitives relació amb l’estat de la qüestió. Amb l’objectiu de demostrar les possibilitats de la tecnologia desenvolupada, s’han dissenyat i testejat dispositius electrònics de RF, concebent-los en l’espai tridimensional. El punt clau és que els dispositius dissenyats serien molt difícils, costosos o directament impossibles de fabricar usant tecnologies convencionals. A remarcar, s’ha dut a terme un estudi sobre inductors cònics, mostrant els avantatges d’aquests components per a aplicacions de banda ampla amb dispositius compactes. Aquests inductors shan fet servir per a la fabricació de filtres passius en 3D. A més, a més, s’han dissenyat filtres 3D per ser impresos en una sola part, una tècnica nova que per produir circuits 3D amb components discrets integrats. A part dels circuits d’elements discrets, s’ha dedicat un capítol sencer als dispositius d’elements distribuïts. S’ha dut a terme un estudi sobre línies de transmissió microstrip helicoidals, les quals aporten una millora important de miniaturització dels segments de línia. Partint d’aquí, aquestes línies s’han implementat en el disseny de transformadors d’impedància, que també milloren en termes d’ample de banda, acobladors híbrids de tipus branch-line i acobladors basats en línies acoblades. Aquests dispositius han resultat tenir millores importants de compacitat respecte els dissenys convencionals fabricats en estructures planars.
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Nilsson, Marcus, and Johan Ruth. "SPC and DOE in production of organic electronics." Thesis, Linköping University, Department of Science and Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6240.
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At Acreo AB located in Norrköping, Sweden, research and development in the field of organic electronics have been conducted since 1998. Several electronic devices and systems have been realized. In late 2003 a commercial printing press was installed to test large scale production of these devices. Prior to the summer of 2005 the project made significant progress. As a step towards industrialisation, the variability and yield of the printing process needed to bee studied. A decision to implement Statistical Process Control (SPC) and Design of Experiments (DOE) to evaluate and improve the process was taken.
SPC has been implemented on the EC-patterning step in the process. A total of 26 Samples were taken during the period October-December 2005. An - and s-chart were constructed from these samples. The charts clearly show that the process is not in statistical control. Investigations of what causes the variation in the process have been performed. The following root causes to variation has been found:
PEDOT:PSS-substrate sheet resistance and poorly cleaned screen printing drums.
After removing points affected by root causes, the process is still not in control. Further investigations are needed to get the process in control. Examples of where to go next is presented in the report. In the DOE part a four factor full factorial experiment was performed. The goal with the experiment was to find how different factors affects switch time and life length of an electrochromic display. The four factors investigated were: Electrolyte, Additive, Web speed and Encapsulation. All statistical analysis was performed using Minitab 14. The analysis of measurements from one day and seven days after printing showed that:
- Changing Electrolyte from E230 to E235 has small effect on the switch time
- Adding additives Add1 and Add2 decreases the switch time after 1 and 7 days
- Increasing web speed decreases the switch time after 1 and 7 days
- Encapsulation before UV-step decreases the switch time after 7 days
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Öhlund, Thomas. "Coated Surfaces for Inkjet-Printed Conductors." Licentiate thesis, Mittuniversitetet, Institutionen för tillämpad naturvetenskap och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-16449.
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In this thesis, a number of commercially available paper substrates of various types are characterized and their characteristics related to the performance of inkjet-printed conductors using silver nanoparticle ink. The evaluated performance variables are electrical conductivity as well as the minimum achievable conductor width and the edge raggedness. It is shown that quick absorption of the ink carrier is beneficial for achieving well defined conductor geometry and high conductivity. Surface roughness with topography variations of sufficiently large amplitude and frequency is detrimental to print definition and conductivity. Porosity is another important factor, where the characteristic pore size is much more important than the total pore volume. A nearly ideal porous coating has large total pore volume but small characteristic pore size, preferably smaller than individual nanoparticles in the ink. Apparent surface energy is important for non-absorbing substrates but of limited importance for coatings with a high absorption rate.Additionally, a concept for improving the geometric definition of inkjet-printed conductors on nonporous films has been demonstrated. By coating the films with polymer–based coatings to provide a means of ink solvent removal, minimum conductor width were reduced a factor 2 or more.Intimately connected to the end performance of printed conductors is a well adapted sintering methodology. A comparative evaluation of a number of selective sintering methods has been performed on paper substrates with different heat tolerance. Pulsed high-power white light was found to be a good compromise between conductivity performance, reliability and production adaptability.The purpose of the work conducted in this thesis is to increase the knowledge base in how surface characteristics of papers and flexible films affect performance of printed nanoparticle structures. This would improve selection, adaption of, or manufacturing of such substrates to suit printed high conductivity patterns such as printed antennas for packaging.I denna avhandling har ett antal kommersiellt tillgängliga papper av olika typ karaktäriserats och deras egenskaper relaterats till prestandan på inkjet-tryckta elektriska ledare tryckta med silvernanopartikelbläck. De undersökta prestandavariablerna är elektrisk ledningsförmåga samt ledarnas minimala linjebredd och kantjämnhet. Det visas att en snabb absorption av bläckets lösningsmedel är gynnsam för både väldefinierad ledningsgeometri och elektrisk ledningsförmåga. Ytråhet med topografiska variationer med tillräckligt stor amplitud och spatiell frekvens korrelerar negativt med tryckdefinition och ledningsförmåga. Porositet är ytterligare en viktig faktor, där karaktäristisk porstorlek är avsevärt viktigare än total porvolym. Nära ideala egenskaper hos en porös bestrykning synes vara en mycket hög total porvolym men med små individuella porer, med fördel mindre än de minsta metallpartiklarna i bläcket. Ytenergi är mycket betydelsefull för icke-absorberande substrat men tappar nästan all sin betydelse för bestrykningar med snabb absorption.Ett koncept för att förbättra den geometriska definitionen på inkjet-tryckta ledare på icke-porösa flexibla filmer har visats. Genom att bestryka filmerna med vissa polymerbaserade material och därmed införa en mekanism för separering av lösningsmedel och partiklar så reducerades ledarnas minimibredd med en faktor 2 eller mer.Intimt förknippad med den slutliga elektriska prestandan på tryckta ledare är också en väl anpassad sintringsmetodik. En jämförande utvärdering av ett flertal selektiva sintringmetoder har genomförts på papper med olika värmetålighet. Pulsat vitt ljus med hög effekt bedömdes som en bra kompromiss mellan elektriska prestanda, tillförlitlighet och anpassningsbarhet för produktionsmiljö.Nyttan med arbetet som presenteras i denna avhandling är att öka kunskapsbasen för hur pappers och flexibla filmers ytegenskaper påverkar prestandan på inkjet-tryckta nanopartikelstrukturer. Detta möjliggör bättre urval, anpassning av, eller tillverkning av sådana substrat för att passa tryckta mönster med hög konduktivitet; som till exempel tryckta antenner på förpackningar.
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Wilson, Antony R. "Modelling and simulation of paradigms for printed circuit board assembly to support the UK's competency in high reliability electronics." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/10236.
Full textAbstract:
The fundamental requirement of the research reported within this thesis is the provision of physical models to enable model based simulation of mainstream printed circuit assembly (PCA) process discrete events for use within to-be-developed (or under development) software tools which codify cause & effects knowledge for use in product and process design optimisation. To support a national competitive advantage in high reliability electronics UK based producers of aircraft electronic subsystems require advanced simulation tools which offer model based guidance. In turn, maximization of manufacturability and minimization of uncontrolled rework must therefore enhance inservice sustainability for 'power-by-the-hour' commercial aircraft operation business models.
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Emord, Nicholas. "High Speed, Micron Precision Scanning Technology for 3D Printing Applications." UNF Digital Commons, 2018. https://digitalcommons.unf.edu/etd/821.
Full textAbstract:
Modern 3D printing technology is becoming a more viable option for use in industrial manufacturing. As the speed and precision of rapid prototyping technology improves, so too must the 3D scanning and verification technology. Current 3D scanning technology (such as CT Scanners) produce the resolution needed for micron precision inspection. However, the method lacks in speed. Some scans can be multiple gigabytes in size taking several minutes to acquire and process. Especially in high volume manufacturing of 3D printed parts, such delays prohibit the widespread adaptation of 3D scanning technology for quality control. The limiting factors of current technology boil down to computational and processing power along with available sensor resolution and operational frequency. Realizing a 3D scanning system that produces micron precision results within a single minute promises to revolutionize the quality control industry.
The specific 3D scanning method considered in this thesis utilizes a line profile triangulation sensor with high operational frequency, and a high-precision mechanical actuation apparatus for controlling the scan. By syncing the operational frequency of the sensor to the actuation velocity of the apparatus, a 3D point cloud is rapidly acquired. Processing of the data is then performed using MATLAB on contemporary computing hardware, which includes proper point cloud formatting and implementation of the Iterative Closest Point (ICP) algorithm for point cloud stitching. Theoretical and physical experiments are performed to demonstrate the validity of the method. The prototyped system is shown to produce multiple loosely-registered micron precision point clouds of a 3D printed object that are then stitched together to form a full point cloud representative of the original part. This prototype produces micron precision results in approximately 130 seconds, but the experiments illuminate upon the additional investments by which this time could be further reduced to approach the revolutionizing one-minute milestone.
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Apaydin, Elif. "Microfabrication Techniques for Printing on PDMS Elastomers for Antenna and Biomedical Applications." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1253138931.
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Доброжан, Олександр Анатолійович, Александр Анатольевич Доброжан, Oleksandr Anatoliiovych Dobrozhan, Анна Олександрівна Салогуб, Анна Александровна Салогуб, Anna Oleksandrivna Salohub, Ярослав Володимирович Знаменщиков, et al. "3D printing of nanoinks based on the metal and semiconductor nanoparticles." Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/66532.
Full textAbstract:
Nowadays, we observe the transition for creation of the domestic and
industry objects from the traditional methods involving the assembling of the
different parts obtained by cutting, molding or otherwise to the additive
manufacturing which refers to the object formation by using a layer-by-layer
deposition of the versatile materials (metals, plastics, glasses, and so on) in
the one 3D printing technological process. In the electronics, the attention
should be given to the especially perspective technology, that is 3D ink
printing of inks based on the metal nanoparticles (Ag, Cu, Sn) to obtain the
printed circuit boards, charge-collecting contacts of thin-film solar cells and
its connections with the external loads. Moreover, the inks based on the
semiconductor materials (Cu2ZnSn(S,Se)4, ZnO) are the promising for the
use in the sensitive elements of photoconverters, thermoelectric generators,
transparent electronics, gas sensors, and touchpads.
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Öhlund, Thomas. "Metal Films for Printed Electronics : Ink-substrate Interactions and Sintering." Doctoral thesis, Mittuniversitetet, Avdelningen för naturvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-23420.
Full textAbstract:
A new manufacturing paradigm may lower the cost and environmental impact of existing products, as well as enable completely new products. Large scale, roll-to-roll manufacturing of flexible electronics and other functionality has great potential. However, a commercial breakthrough depends on a lower consumption of materials and energy compared with competing alternatives, and that sufficiently high performance and reliability of the products can be maintained. The substrate constitutes a large part of the product, and therefore its cost and environmental sustainability are important. Electrically conducting thin films are required in many functional devices and applications. In demanding applications, metal films offer the highest conductivity. In this thesis, paper substrates of various type and construction were characterized, and the characteristics were related to the performance of inkjet-printed metal patterns. Fast absorption of the ink carrier was beneficial for well-defined pattern geometry, as well as high conductivity. Surface roughness with topography variations of sufficiently large amplitude and frequency, was detrimental to the pattern definition and conductivity. Porosity was another important factor, where the characteristic pore size was much more important than the total pore volume. Apparent surface energy was important for non-absorbing substrates, but of limited importance for coatings with a high absorption rate. Applying thin polymer–based coatings on flexible non-porous films to provide a mechanism for ink solvent removal, improved the pattern definition significantly. Inkjet-printing of a ZnO-dispersion on uncoated paper provided a thin spot-coating, allowing conductivity of silver nanoparticle films. Conductive nanoparticle films could not form directly on the uncoated paper. The resulting performance of printed metal patterns was highly dependent on a well adapted sintering methodology. Several sintering methods were examined in this thesis, including conventional oven sintering, electrical sintering, microwave sintering, chemical sintering and intense pulsed light sintering. Specially designed coated papers with modified chemical and physical properties, were utilized for chemical low-temperature sintering of silver nanoparticle inks. For intense pulsed light sintering and material conversion of patterns, custom equipment was designed and built. Using the equipment, inkjet-printed copper oxide patterns were processed into highly conducting copper patterns. Custom-designed papers with mesoporous coatings and porous precoatings improved the reliablility and performance of the reduction and sintering process. The thesis aims to clarify how ink-substrate interactions and sintering methodology affect the performance and reliability of inkjet-printed nanoparticle patterns on flexible substrates. This improves the selection, adaptation, design and manufacturing of suitable substrates for inkjet-printed high conductivity patterns, such as circuit boards or RFID antennas.
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Hrabal, Michal. "Development of Light Emitting Electroluminescent Device by Means of Material Printing." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-402111.
Full textAbstract:
Cílem této práce je vývoj světelného zdroje založeného na technologii tlustostěnného elektroluminiscenčního panelu napájeného střídavým napětím (ACPEL). V současné době se jedná se o jedinou technologii založenou na metodách materiálového tisku vhodnou pro přípravu velkoplošných, flexibilních a vzorovaných zdrojů světla. Důraz je v této práci kladen na představení, prozkoumání a odstranění typických problémů, které jsou spojovány s touto technologií. Tyto problémy jsou omezený odstín barvy emitovaného světla a dlouhodobá stabilita elektroluminiscenčního prvku, který je vystaven vlivům prostředí. Rešeršní část dizertační práce je zaměřena na představení a identifikaci depozičních technik, vhodných pro reprodukovatelnou přípravu ACPEL panelů. Dalším cílem je identifikace fyzikálních parametrů, vhodných pro charakterizaci velkoplošných zdrojů světla. Praktickým cílem práce je nalezení vhodné metodologie pro popis a charakterizaci panelů, jakožto plošných světelných zdrojů. Fotometrická veličina jas L a spotřeba elektrické energie P byly vyhodnoceny jako vhodné parametry, určující aplikaci ACPEL panelů. Na modrém panelu bylo dosaženo maximální hodnoty jasu L = 133 cd•m2 při napětí Upp = 500 V a frekvenci f = 1000 Hz. Hodnoty spotřeby elektrické energie, vztažené na jednotkovou plochu panelů zkoumaných v této práci, jsou (7±3) mW. Tyto dosažené hodnoty dělají ze světelných zdrojů založených na ACPEL technologii zajímavé kandidáty pro různé aplikace. Vlivu rostoucí amplitudy a frekvence budícího napětí na dlouhodobou stabilitu panelů je důležitým cílem této práce. Pro popis stability byly zavedeny parametry L50 and L75. Bylo zjištěno, že rostoucí frekvence budícího napětí zkracuje životnost panelů. Laminovaný panel napájený napětím s přibližně trojnásobně vyšší frekvencí vykazoval přibližně třetinové hodnoty parametrů L50 a L75. Nejvyšších hodnot stabilitních parametrů dosahoval panel enkapsulován mezi skleněné pláty – přibližně sedminásobnou hodnotu oproti laminovanému panelu s trojnásobnou frekvencí. Optimální stability panelů lze dosáhnout při nastavení frekvence v rozmezí 400–800 Hz a zapouzdřením mezi sklo. Úzká paleta odstínů barev emitovaného světla je jeden z typických problémů, který dále zkoumán v dizertační práci. Tato práce zkoumá nadějnou metodu, přídavek vhodného materiálu pro konverzi barvy (CCM). Nový derivát diketopyrrolopyrrolu (DPP), absorbující v modré oblasti, byl přidán k modrému fosforu a byl pozorován sedminásobný narůst hodnot absolutního spektrálního ozáření v oblasti vlnových délek odpovídajících maximální emisi CCM materiálu. Jednoduchost přípravy vyvinutých zdrojů světla spolu s velmi nízkou spotřebou a vysokou dobou života dělají z ACPEL panelů zajímavé kandidáty pro podsvícení prvků například v automobilovém průmyslu, pro dekorativní osvětlení, pro „branding“ – zvýraznění reklamních značek.
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Cook, Benjamin Stassen. "Vertical integration of inkjet-printed RF circuits and systems (VIPRE) for wireless sensing and inter/intra-chip communication applications." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51844.
Full textAbstract:
Inkjet-printing is a technology which has for the last decade been exploited to fabricate flexible RF components such as antennas and planar circuit elements. However, the limitations of feature size and single layer fabrication prevented the demonstration of compact, and high efficiency RF components operating above 10 GHz into the mm-Wave regime which is critical to silicon integration and fully-printed modules. To overcome these limitations, a novel vertically-integrated fully inkjet-printed process has been developed and characterized up to the mm-Wave regime which incorporates up to five highly conductive metal layers, variable thickness dielectric layers ranging from 200 nm to 200 um, and low resistance through-layer via interconnects. This vertically-integrated inkjet printed electronics process, tagged VIPRE, is a first of its kind, and is utilized to demonstrate fully additive RF capacitors, inductors, antennas, and RF sensors operating up to 40 GHz. In this work, the first-ever fully inkjet printed multi-layer RF devices operating up to 40 GHz with high-performance are demonstrated, along with a demonstration of the processing techniques which have enabled the printing of multi-layer RF structures with multiple metal layers, and dielectric layers which are orders of magnitude thicker than previoulsy demonstrated inkjet-printed structures. The results of this work show the new possibilities in utilizing inkjet printing for the post-processing of high-efficiency RF inductors, capacitors, and antennas and antenna arrays on top of silicon to reduce chip area requirements, and for the production of entirely printed wireless modules.