Дисертації з теми "3D conductive polymer"

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1

SCORDO, GIORGIO. "A novel electrical conductive resin for stereolithographic 3D printing." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2899751.

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2

Bertolini, Mayara Cristina. "Flexible and 3D printable conductive composites for pressure sensor applications." Doctoral thesis, Università degli studi di Trento, 2022. https://hdl.handle.net/11572/360281.

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Анотація:
O objetivo deste estudo foi o desenvolvimento de compósitos poliméricos flexíveis e altamente condutores elétricos preparados por moldagem por compressão e por fabricação de filamentos fundidos (FFF) para possíveis aplicações como materiais piezoresistivos ou piezoelétricos para sensores de compressão. Compósitos baseados em misturas de poli(fluoreto de vinilideno)/poliuretano termoplástico (PVDF/TPU) como matriz e contendo várias frações de negro de fumo-polipirrol (CB-PPy) como aditivo condutor foram preparados. Diversas técnicas de caracterização foram realizadas para avaliar as propriedades mecânicas, térmicas, químicas e elétricas, morfologia e printabilidade dos materiais investigados. Primeiro, blendas de PVDF/TPU com diferentes composições foram produzidas por mistura por fusão seguida de moldagem por compressão. Os resultados mostraram que a flexibilidade desejada para os materiais foi melhorada com a adição de TPU aos compósitos de PVDF. As imagens SEM evidenciaram a obtenção de uma blenda co-contínua com 50/50 vol% de PVDF/TPU. As blendas compostas de PVDF/TPU 38/62 vol% e a blenda co-contínua de PVDF/TPU 50/50 vol% foram selecionadas como matrizes para a preparação de compósitos moldados por compressão e impressos em 3D a fim de alcançar uma ótima combinação entre condutividade, propriedades mecânicas e printabilidade. Várias quantidades de negro de fumo-polipirrol, de 0 a 15%, foram adicionadas às blendas selecionadas para aumentar a condutividade elétrica dos compósitos e possivelmente atuar como agente nucleante para a fase cristalina do PVDF a fim de aumentar sua resposta piezoelétrica. A adição de CB-PPy aumentou a condutividade elétrica de todos os compósitos. No entanto, a condutividade elétrica dos compósitos baseados em blendas co-contínuas PVDF/TPU 50/50 vol% foi maior do que as encontradas para os compósitos de PVDF/TPU 38/62 vol% com mesma concentração de aditivo. De fato, o limiar de percolação elétrico dos compósitos com blenda co-contínua foi de 2%, enquanto o limiar de percolação elétrico dos compósitos compostos da blenda não contínua foi de 5%. Com relação às propriedades mecânicas, a incorporação do aditivo condutor nas blendas resultou em materiais mais rígidos com maior módulo de elasticidade, menor alongamento na ruptura e maior módulo de armazenamento. O módulo de armazenamento (G') e a viscosidade complexa (η*) dos compósitos aumentaram com a adição de CB-PPy. O limiar de percolação reológico foi de 3% para PVDF/TPU/CB-PPy 38/62 vol% e 1% para PVDF/TPU/CB-PPy 50/50 vol%, indicando que uma quantidade maior de carga poderia comprometer a processabilidade dos compósitos. A adição de CB-PPy também resultou na redução dos valores de Tg e Tm dos compósitos devido à redução da mobilidade das cadeias poliméricas. Com base na condutividade elétrica e no comportamento mecânico dos compósitos, três composições diferentes foram selecionadas para a extrusão de filamentos para serem posteriormente utilizados no processo de impressão 3D. No geral, as peças impressas em 3D apresentaram propriedades mecânicas e elétricas inferiores devido à presença de vazios, defeitos e camadas sobrepostas que podem dificultar o fluxo de elétrons. Os valores de condutividade elétrica dos compósitos impressos em 3D de PVDF/TPU/CB-PPy 38/62 vol% contendo 5% e 6% de CB-PPy são de uma a sete ordens de grandeza menores do que os encontrados para os compósitos com a mesma composição moldados por compressão. Mesmo que o valor da condutividade elétrica para o compósito PVDF/TPU 38/62 vol% com 6% de CB-PPy moldado por compressão foi de 1,94x10-1 S•m-1, o compósito impresso em 3D com a mesma composição mostrou um valor muito baixo de condutividade elétrica de 6,01x10-8 S•m-1. Por outro lado, o compósito co-contínuo de PVDF/TPU 50/50 vol% com 10% de aditivo impresso em 3D apresentou um alto valor de condutividade elétrica de 4,14×100 S•m-1 mesmo após o processo de impressão. Além disso, as respostas piezoresistivas dos compósitos foram investigadas. Para os compósitos PVDF/TPU/CB-PPy 38/62 vol%, as amostras moldadas por compressão e impressas em 3D com 5% e 6% de CB-PPy exibiram boa resposta piezoresistiva. No entanto, apenas os compósitos com 6% de aditivo apresentaram valores elevados de sensibilidade e gauge factor, atuação em ampla faixa de pressão e respostas piezoresistivas reprodutíveis durante a aplicação de 100 ciclos de compressão/descompressão para ambos os métodos de fabricação. Por outro lado, para os compósitos co-contínuos de PVDF/TPU/CB-PPy apenas a amostra moldada por compressão com 5% de CB-PPy apresentou respostas piezorresistivas boas e reprodutíveis. A cristalinidade e o teor de fase β do PVDF foram investigados para os compósitos. Embora o grau de cristalinidade das amostras tenha diminuído com a adição de CB-PPy, a porcentagem de fase β no PVDF aumentou. O coeficiente piezoelétrico d33 das amostras aumentou com a porcentagem de fase β. A adição de 6% ou mais de CB-PPy foi necessária para aumentar significativamente o coeficiente piezoelétrico (d33) dos compósitos. O conteúdo de fase β e as respostas piezoelétricas do PVDF foram menores para as amostras preparadas por FFF. Por fim, como pesquisa colateral, a eficiência de blindagem contra interferência eletromagnética (EMI-SE) foi medida para todos os compósitos. Compósitos com maior condutividade elétrica apresentaram melhor blindagem da radiação eletromagnética. Além disso, os compósitos baseados na blenda co-contínua apresentaram maior eficiência de blindagem contra EMI do que os compósitos de PVDF/TPU 38/62 vol%. O principal mecanismo de blindagem foi a absorção para todos os compósitos. As amostras preparadas por FFF apresentaram respostas de EMI-SE menores quando comparadas às amostras moldadas por compressão.
The aim of this study was the development of flexible and highly electrically conductive polymer composites via compression molding and fused filament fabrication for possible applications as piezoresistive or piezoelectric materials for pressure sensors. Composites based on blends of poly(vinylidene fluoride)/thermoplastic polyurethane (PVDF/TPU) as matrix and containing various fractions of carbon black-polypyrrole (CB-PPy) as conductive filler were prepared. Several characterization techniques were performed in order to evaluate the mechanical, thermal, chemical and electrical properties, morphology and printability of the investigated materials. First, PVDF/TPU blends with different compositions were prepared by melt compounding followed by compression molding. The results showed that the flexibility aimed for the final materials was improved with the addition of TPU to PVDF composites. SEM images evidenced the achievement of a co-continuous blend comprising 50/50 vol% of PVDF/TPU. The blends composed of PVDF/TPU 38/62 vol% and the co-continuous blend of PVDF/TPU 50/50 vol% were selected as matrices for the preparation of compression molded and 3D printed composites in order to achieve an optimal compromise between electrical conductivity, mechanical properties and printability. Various amounts of carbon black-polypyrrole, from 0 up to 15%, were added to the selected blends in order to rise the electrical conductivity of the composites and to possible act as nucleating filler for the β crystalline phase of PVDF in order to increase its piezoelectric response. The addition of CB-PPy increased the electrical conductivity of all composites. However, the electrical conductivity of composites based on PVDF/TPU 50/50 vol% co-continuous blends was higher than those found for PVDF/TPU 38/62 vol% composites at the same filler content. Indeed, the electrical percolation threshold of the conductive co-continuous composite blends was 2%, while the electrical percolation threshold of the composites with the nonco-continuous composite blends was 5%. With respect to the mechanical properties, the incorporation of the filler into the blends leaded to more rigid materials with higher elastic modulus, lower elongation at break and higher storage modulus. The storage modulus (G’) and complex viscosity (η*) of the composites increased with the addition of CB-PPy. The rheological percolation threshold was found to be 3% for PVDF/TPU/CB-PPy 38/62 vol% and 1% for PVDF/TPU/CB-PPy 50/50 vol%, indicating that higher amount of filler could compromise the processability of the composites. The addition of CB-PPy also resulted in a reduction on the Tg and Tm values of the composites due to the reduction of the mobility of the polymeric chains. Based on the electrical conductivity and mechanical behavior of the composites, three different compositions were selected for the extrusion of filaments to be used in a 3D printing process. Overall, the 3D printed parts presented lower mechanical and electrical properties because of the presence of voids, defects and overlapping layers that can hinder the flow of electrons. The electrical conductivity values of PVDF/TPU/CB-PPy 38/62 vol% composites containing 5% and 6 wt% of CB-PPy 3D printed samples are one to seven orders of magnitude lower than those found for compression molded composites with the same composition. Even if the electrical conductivity value for PVDF/TPU 38/62 vol% compression molded composite with 6% of CB-PPy was as high as 1.94x10-1 S•m-1, the 3D printed composite with same composition showed a very low electrical conductivity of 6.01x10-8 S•m-1. On the other hand, the 3D printed co-continuous composite PVDF/TPU 50/50 vol% with 10% of filler displayed a high value of electrical conductivity of 4.14×100 S•m-1 even after the printing process. Moreover, the piezoresistive responses of the composites were investigated. For PVDF/TPU/CB-PPy 38/62 vol% composites, the compression molded and 3D printed samples with 5% and 6% of CB-PPy exhibited good piezoresistive response. However, only the composites with 6% displayed high sensitivity and gauge factor values, large pressure range and reproducible piezoresistive responses under 100 cycles for both methods. On the other hand, for PVDF/TPU/CB-PPy co-continuous composites only the compression molded sample with 5% of CB-PPy presented good and reproducible piezoresistive responses. The crystallinity and β phase content of PVDF were investigated for the composites. Althought the degree of crystallinity of the samples decreased with the addition of CB-PPy, the percentage of β phase in PVDF was increased. The piezoelectric coefficient d33 of the samples increased with the percentage of β phase. The addition of 6% or more of CB-PPy was necessary to increase significatively the piezoelectric coefficient (d33) of the composites. The β phase content and piezoelectric responses of PVDF were lower for samples prepared by FFF. Finally, as a collateral research, the electromagnetic interference shielding effectiveness (EMI-SE) were measured for all composites. Composites with higher electrical conductivity showed better shielding of the electromagnetic radiation. In addition, composites based on the co-continuous blend displayed higher EMI shielding efficiency than 38/62 vol% composites. The main mechanism of shielding was absorption for all composites. Specimens prepared by FFF displayed diminished EMI-SE responses when compared to compression molded samples.
Lo scopo di questo studio è lo sviluppo di compositi polimerici flessibili e ad elevata conducibilità elettrica tramite stampaggio a compressione e manifattura additiva (fused filament fabrication) per possibili applicazioni come materiali piezoresistivi o piezoelettrici in sensori di pressione. In particolare, sono stati preparati compositi a base di miscele di poli(vinilidene fluoruro)/poliuretano termoplastico (PVDF/TPU) come matrice e contenenti varie frazioni di nerofumo-polipirrolo (CB-PPy) come riempitivo conduttivo. Sono state utilizzate diverse tecniche di caratterizzazione al fine di valutare le proprietà meccaniche, termiche, chimiche ed elettriche, la morfologia e la stampabilità dei materiali ottenuti. In primo luogo, miscele PVDF/TPU con diverse composizioni sono state preparate mediante mescolatura allo stato fuso seguita da stampaggio a compressione. I risultati hanno mostrato che la flessibilità del PVDF viene notevolemente migliorata dall’aggiunta di TPU. Le immagini SEM hanno evidenziato il raggiungimento di una miscela co-continua per una composizione 50/50% in volume di PVDF/TPU. Le miscele composte da PVDF/TPU 38/62 vol% e la miscela co-continua di PVDF/TPU 50/50 vol% sono state selezionate come matrici per la preparazione di compositi per stampaggio a compressione e manifattura additiva al fine di ottenere un compromesso ottimale tra conducibilità, proprietà meccaniche e stampabilità. Alle miscele selezionate sono state aggiunte varie quantità di nerofumo-polipirrolo, dallo 0 al 15%, per aumentare la conducibilità elettrica dei compositi ed eventualmente fungere da additivo nucleante per la fase β cristallina del PVDF al fine di aumentarne la risposta piezoelettrica. L'aggiunta di CB-PPy ha aumentato la conduttività elettrica di tutti i compositi. Tuttavia, la conduttività elettrica dei compositi basati su miscele co-continue di PVDF/TPU 50/50% in volume era superiore a quella trovata per compositi PVDF/TPU 38/62% in volume con lo stesso contenuto di riempitivo. Infatti, la soglia di percolazione elettrica delle miscele conduttive era del 2%, mentre la soglia di percolazione elettrica dei compositi con miscele composite non continue era del 5%. Per quanto riguarda le proprietà meccaniche, l'incorporazione del riempitivo nelle mescole ha portato a materiali più rigidi con modulo elastico più elevato, allungamento a rottura inferiore e modulo conservativo più elevato. Il modulo conservativo (G') e la viscosità complessa (η*) dei compositi sono aumentate con l'aggiunta di CB-PPy. La soglia di percolazione reologica è risultata essere del 3% per PVDF/TPU/CB-PPy 38/62 vol% e dell'1% per PVDF/TPU/CB-PPy 50/50 vol%, indicando che una maggiore quantità di riempitivo potrebbe compromettere la processabilità dei compositi. L'aggiunta di CB-PPy ha comportato anche una riduzione dei valori di Tg e Tm dei compositi a causa della riduzione della mobilità delle catene polimeriche. Sulla base della conduttività elettrica e del comportamento meccanico dei compositi, sono state selezionate tre diverse composizioni per l'estrusione di filamenti da utilizzare in un processo di stampa 3D. Nel complesso, le parti stampate in 3D presentavano proprietà meccaniche ed elettriche inferiori a causa della presenza di vuoti, difetti e strati sovrapposti che possono ostacolare il flusso di elettroni. I valori di conducibilità elettrica dei compositi PVDF/TPU/CB-PPy 38/62 vol% contenenti il 5% e il 6% di CB-PPy di campioni stampati in 3D sono da uno a sette ordini di grandezza inferiori a quelli trovati per i compositi stampati a compressione con la stessa composizione. Anche se il valore di conducibilità elettrica per il composito stampato a compressione PVDF/TPU 38/62 vol% con il 6% di CB-PPy era pari a 1,94x10-1 S•m-1, il composito stampato in 3D con la stessa composizione ha mostrato un valore molto basso di conducibilità elettrica, pari a 6,01x10-8 S•m-1. D'altra parte, il composito PVDF/TPU 50/50 vol% stampato in 3D con il 10% di riempitivo ha mostrato un elevato valore di conducibilità elettrica, pari a 4,14 × 100 S•m-1, anche dopo il processo di stampa. Inoltre, sono state studiate le risposte piezoresistive dei compositi. Per i compositi PVDF/TPU/CB-PPy 38/62 vol%, i campioni stampati a compressione e stampati in 3D con il 5% e il 6% di CB-PPy hanno mostrato una buona risposta piezoresistiva. Tuttavia, solo i compositi con il 6% hanno mostrato valori di sensibilità e gauge factor elevati, ampio intervallo di pressione e risposte piezoresistive riproducibili in 100 cicli per entrambi i metodi. D'altra parte, per i compositi co-continui PVDF/TPU/CB-PPy solo il campione stampato a compressione con il 5% di CB-PPy ha presentato risposte piezoresistive adeguate e riproducibili. La cristallinità e il contenuto di fase β del PVDF sono stati studiati per i compositi. Sebbene il grado di cristallinità dei campioni diminuisca con l'aggiunta di CB-PPy, la percentuale di fase β in PVDF risulta aumentata. Il coefficiente piezoelettrico d33 dei campioni aumenta anch’esso con la percentuale di fase β. L'aggiunta del 6% o più di CB-PPy è stata necessaria per aumentare significativamente il coefficiente piezoelettrico (d33) dei compositi. Il contenuto di fase β e le risposte piezoelettriche del PVDF sono inferiori per i campioni ottenuti mediante stampa 3D. Infine, come ricerca collaterale, è stata misurata l'efficacia della schermatura contro le interferenze elettromagnetiche (EMI-SE) per tutti i compositi. I compositi con una maggiore conduttività elettrica hanno mostrato una migliore schermatura della radiazione elettromagnetica. Inoltre, i compositi basati sulla miscela co-continua hanno mostrato un'efficienza di schermatura EMI maggiore rispetto ai compositi a 38/62% in volume. Per tutti i compositi, il principale meccanismo di schermatura è l'assorbimento. I campioni preparati mediante manifattura additiva hanno mostrato risposte EMI-SE inferiori rispetto ai campioni stampati a compressione.
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Hashemi, Sanatgar Razieh. "FDM 3D printing of conductive polymer nanocomposites : A novel process for functional and smart textiles." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I052/document.

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Анотація:
Le but de cette étude est d’exploiter les fonctionnalités des nano-Composites Polymères Conducteurs (CPC) imprimés en utilisant la technologie FDM (modélisation par dépôt de monofilament en fusion) pour le développement de textiles fonctionnels et intelligents. L’impression 3D présente un fort potentiel pour la création d’une nouvelle classe de nanocomposites multifonctionnels. Par conséquent, le développement et la caractérisation des polymères et nanocomposites fonctionnels et imprimables en 3D sont nécessaires afin d’utiliser l’impression 3D comme nouveau procédé de dépôt de ces matériaux sur textiles. Cette technique introduira des procédés de fonctionnalisation de textiles plus flexibles, économes en ressources et très rentables, par rapport aux procédés d'impression conventionnels tels que la sérigraphie et le jet d'encre. L’objectif est de développer une méthode de production intégrée et sur mesure pour des textiles intelligents et fonctionnels, afin d’éviter toute utilisation d'eau, d'énergie et de produits chimiques inutiles et de minimiser les déchets dans le but d’améliorer l'empreinte écologique et la productivité. La contribution apportée par cette thèse consiste en la création et la caractérisation de filaments CPC imprimables en 3D, le dépôt de polymères et de nanocomposites sur des tissus et l’étude des performances en termes de fonctionnalité des couches de CPC imprimées en 3D. Dans un premier temps, nous avons créé des filaments de CPC imprimables en 3D, notamment des nanotubes de carbone à parois multiples (MWNT) et du noir de carbone à haute structure (Ketjenblack) (KB), incorporés dans de l'acide polylactique (PLA) à l'aide d'un procédé de mélange à l'état fondu. Les propriétés morphologiques, électriques, thermiques et mécaniques des filaments et des couches imprimées en 3D ont été étudiées. Deuxièmement, nous avons déposé les polymères et les nanocomposites sur des tissus à l’aide d’une impression 3D et étudié leur adhérence aux tissus. Enfin, les performances des couches de CPC imprimées en 3D ont été analysées sous tension et force de compression appliquées. La variation de la valeur de la résistance correspondant à la charge appliquée permet d’évaluer l'efficacité des couches imprimées en tant que capteur de pression / force. Les résultats ont montré que les nanocomposites à base de PLA, y compris MWNT et KB, sont imprimables en 3D. Les modifications des propriétés morphologiques, électriques, thermiques et mécaniques des nanocomposites avant et après l’impression 3D nous permettent de mieux comprendre l’optimisation du procédé. De plus, différentes variables du procédé d’impression 3D ont un effet significatif sur la force d'adhérence des polymères et des nanocomposites déposés sur les tissus. Nous avons également développé des modèles statistiques fiables associés à ces résultats valables uniquement pour le polymère et le tissu de l’étude. Enfin, les résultats démontrent que les mélanges PLA/MWNT et PLA/KB sont de bonnes matières premières piézorésistives pour l’impression 3D. Elles peuvent être potentiellement utilisées dans l’électronique portable, la robotique molle et la fabrication de prothèses, où une conception complexe, multidirectionnelle et personnalisable est nécessaire
The aim of this study is to get the benefit of functionalities of fused deposition modeling (FDM) 3D printed conductive polymer nanocomposites (CPC) for the development of functional and smart textiles. 3D printing holds strong potential for the formation of a new class of multifunctional nanocomposites. Therefore, development and characterization of 3D printable functional polymers and nanocomposites are needed to apply 3D printing as a novel process for the deposition of functional materials on fabrics. This method will introduce more flexible, resource-efficient and cost-effective textile functionalization processes than conventional printing process like screen and inkjet printing. The goal is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity. The contribution of this thesis is the creation and characterization of 3D printable CPC filaments, deposition of polymers and nanocomposites on fabrics, and investigation of the performance of the 3D printed CPC layers in terms of functionality. Firstly, the 3D printable CPC filaments were created including multi-walled carbon nanotubes (MWNT) and high-structured carbon black (Ketjenblack) (KB) incorporated into a biobased polymer, polylactic acid (PLA), using a melt mixing process. The morphological, electrical, thermal and mechanical properties of the 3D printer filaments and 3D printed layers were investigated. Secondly, the performance of the 3D printed CPC layers was analyzed under applied tension and compression force. The response for the corresponding resistance change versus applied load was characterized to investigate the performance of the printed layers in terms of functionality. Lastly, the polymers and nanocomposites were deposited on fabrics using 3D printing and the adhesion of the deposited layers onto the fabrics were investigated. The results showed that PLA-based nanocomposites including MWNT and KB are 3D printable. The changes in morphological, electrical, thermal, and mechanical properties of nanocomposites before and after 3D printing give us a great understanding of the process optimization. Moreover, the results demonstrate PLA/MWNT and PLA/KB as a good piezoresistive feedstock for 3D printing with potential applications in wearable electronics, soft robotics, and prosthetics, where complex design, multi-directionality, and customizability are demanded. Finally, different variables of the 3D printing process showed a significant effect on adhesion force of deposited polymers and nanocomposites onto fabrics which has been presented by the best-fitted model for the specific polymer and fabric
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Oziat, Julie. "Electrode 3D de PEDOT : PSS pour la détection de métabolites électrochimiquement actifs de Pseudomonas aeruginosa." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM026/document.

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Анотація:
Lors d’infections, l'identification rapide des micro-organismes est cruciale pour améliorer la prise en charge du patient et mieux contrôler l'usage des antibiotiques. L’électrochimie présente plusieurs avantages pour les tests rapides : elle permet des analyses in situ, faciles et peu chères dans la plupart des liquides. Son utilisation pour l’identification bactérienne est récente et provient de la découverte de molécules donnant de forts signaux redox dans le surnageant de bactéries du genre Pseudomonas.Cette thèse s’intéresse à l’analyse de surnageants de la bactérie Pseudomonas aeruginosa, 4e cause de maladies nosocomiales en Europe. Tout d’abord, l’intérêt de l’analyse électrochimique de surnageants de culture dans une visée d’identification a été évalué. Pour cela, après l’étude de 4 potentiels biomarqueurs de la présence de cette bactérie en solutions modèles, l’analyse électrochimiques de surnageant de plusieurs souches P. aeruginosa a été effectuée. Les résultats obtenus sont prometteurs. Ils mettent en évidence une signature électrochimique complexe et souche-dépendante du surnageant.La suite de la thèse s’est intéressée à l’amplification de la détection électrochimique grâce à l’utilisation du polymère conducteur PEDOT:PSS. Il a été choisi pour ses bonnes propriétés électrochimiques, sa biocompatibilité et sa facilité de mise en forme. Il a tout d’abord été utilisé sous forme de films minces pour confirmer son pouvoir d’amplification. Une électrode 3D a ensuite été fabriquée par lyophilisation. L’utilisation de ce type d’électrode permet d’amplifier encore la détection en augmentant la surface d’échange mais aussi en confinant les bactéries dans l'électrode
During infections, microorganisms fast identification is critical to improve patient treatment and to better manage antibiotics use. Electrochemistry exhibits several advantages for rapid diagnostic: it enables easy, cheap and in situ analysis in most liquids. Its use for bacterial identification is recent and comes from the discovery of molecules giving strong redox signals in the bacterial supernatant of the Pseudomonas genus.This thesis focuses on the supernatants analysis of the bacterium Pseudomonas aeruginosa. This bacteria is the fourth cause of nosocomial infections in Europe. First, the interest of supernatants electrochemical analysis for identification was evaluated. For this, after the study of four redox biomarkers of this bacterium in model solutions, supernatant electrochemical analysis of several strains of P. aeruginosa was performed. The results are promising. They highlight a complex strain-dependant electrochemical signature of the supernatant.Following, we focused in the amplification of the electrochemical detection through the use of the conductive polymer PEDOT: PSS. This polymer was chosen for its good electrochemical properties, its biocompatibility and its easy shaping. It was first used as a thin films to confirm its amplification power through biomarker adsorption. Then, a 3D electrode was made by freeze drying. The use of this type of electrode can further amplify the detection by increasing the exchange surface as well as confining the bacteria in the electrode
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5

Sandron, Marco. "Mils - Stampante per la creazione di PCB (printed circuit board) con polimero." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19757/.

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Анотація:
Nella mia carriera universitaria mi sono imbattuto in progetti che necessitavano di un circuito elettronico che in alcuni casi costituiva una parte fondamentale e che veniva valutata. Per la realizzazione di questi circuiti è stata utilizzata l’elettronica open source, di conseguenza è stato necessario collegare tra di loro varie schede e anche alcuni componenti. Questi collegamenti non potevano essere eseguiti solo con semplici cavi elettrici ma necessitavano si supporti fisici anche per posizionare in modo ordinato i componenti e sono state utilizzate perciò basette millefori. I collegamenti eseguiti con cavi elettrici occupano spazio e rendono difficoltose le riparazioni in caso di guasto o mal funzionamento inoltre la qualità finale del circuito creato con le basette millefori sono una problematica nel realizzare circuiti per una piccola serie. Ho voluto quindi trovare una soluzione per questo, pensando a qualcosa di economico, rapido e facile da utilizzare, con una certa qualità del prodotto finale. Nella fase di ricerca ho notato che questa problematica è presente anche all’interno dei FabLab, dove la prototipazione, la personalizzazione e la piccola serie sono questioni fondamentali. Qui le tecnologie non sono poche (pantografo CNC, la stampante 3D e taglio laser) e quindi ho cercato di capire se la soluzione per risolvere il problema potesse essere già presente o derivare da quelle presenti, ponendomi in un’ottica di riciclo e riutilizzo a fine vita del circuito e dei sui componenti. La soluzione finale ne riprende la tecnologia base, le forme e i componenti fisici ed elettronici e utilizza una tipologia di materiale per la costruzione dei collegamenti tra i vari componenti elettronici, che è presente e utilizzato ampiamente all’interno dei FabLab, in varie tipologie e con varie caratteristiche. Questa può condurre corrente solo se opportunamente trattato, perché naturalmente ha l’effetto opposto cioè quello di isolare, si tratta del filamento di polimero.
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6

Liu, Shaohua, Faxing Wang, Renhao Dong, Tao Zhang, Jian Zhang, Zhikun Zheng, Yiyong Mai, and Xinliang Feng. "Soft-Template Construction of 3D Macroporous Polypyrrole Scaffolds." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235502.

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7

Anhorn, Michael J. "Nitrogen Rich Porous Organic Frameworks: Proton Conduction Behavior of 3D Benzimidazole and Azo-linked Polymers." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5448.

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Анотація:
Nitrogen-rich porous organic frameworks show great promise for use as acid-doped proton conducting membranes, due to their high porosity, excellent chemical and thermal stability, ease of synthesis, and high nitrogen content. Aided by very high surface area and pore volume, the material has the ability to adsorb high amounts of H3PO4 into its network, which creates a proton rich environment, capable of facile proton conduction. The morphology and chemical environment, doping behavior, and proton conduction of these materials were investigated. With such high acid-doping, ex-situ studies revealed that under anhydrous conditions, PA@BILP-16 (AC) produced a proton conductivity value of 5.8 x 10-2 S cm-1 at 60 °C and PA@ALP-6 showed a slightly higher value of 5.91 x 10-2 S cm-1 at 60 °C. With such promising results, in-situ experiments with various analogues are scheduled to be conducted in the near future.
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8

Bou-Saleh, Ziad. "Nickel-based 3D electrocatalyst layers for production of hydrogen by water electrolysis in an acidic medium." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112559.

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Анотація:
This thesis discusses results on the development of three-dimensional (3D) Ni-based electrocatalytic layers for hydrogen production by water electrolysis in an acidic medium. This is of relevance to the development of polymer-electrolyte-membrane (PEM) hydrogen generators, which are promising hydrogen production systems suitable for both residential and industrial applications.
It was demonstrated that patterning of a glassy carbon electrode substrate with a 3D polyaniline (PANI) matrix is a convenient way of increasing the electrocatalytically active surface area of electrodeposited Ni, and hence its apparent electrocatalytic activity. The optimized PANI/Ni electrocatalyst layer showed a significantly higher activity in the hydrogen evolution reaction (HER) then a commercially available Ni-plate surface (control surface).
It was also demonstrated that it is possible to produce a Ni-based HER electrocatalyst layer by synthesizing Ni nanoparticles and supporting them on Vulcan carbon. This electrocatalyst also offered a significantly higher electrocatalytic activity in the HER then the control surface, but lower then the optimized PANI/Ni electrocatalyst.
The electrocatalytic activity of the optimized PANI/Ni layer was also compared to the activity of a 3D catalyst produced by electro-coating a porous reticulated vitreous carbon (RVC) substrate with Ni. This electrocatalyst showed the highest HER electrocatalytic activity among the investigated layers when tested under potentiodynamic polarization conditions. However, under the potentiostatic conditions, the optimized PANI/Ni layer showed the highest electrocatalytic activity.
The mechanisms and kinetics of the HER on the produced electrocatalysts was also investigated, as well as the electrocatalyst layers' surface morphology and crystalline structure.
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9

Ferro, Magali. "Development of conducting polymer devices for the monitoring of in vitro barrier tissue models." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEM017.

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Анотація:
La règlementation européenne des 3Rs (Remplacer, Réduire, Raffiner) impose de diminuer le nombre d’animaux utilisé à des fins de recherches scientifiques. Elle répond à des exigences éthiques en soutenant le développement de méthodes alternatives. Dans cet objectif, les modèles cellulaires in vitro connaissent un essor important notamment grâce à la possibilité d’utiliser des cellules humaines pour reproduire des tissus ou des organes en laboratoire. Les récents progrès en micro-fabrication et techniques d’ingénierie tissulaire ont permis de se rapprocher des conditions physiologiques des tissus reproduits en évoluant notamment vers des configurations en 3-Dimension. L’intégration de techniques de caractérisation pour rendre observable les phénomènes biologiques à l’échelle cellulaire ou tissulaire est inhérente au développement des modèles in vitro notamment pour leur utilisation en toxicologie. Au cours de cette thèse, j’exploite les possibilités qu’offre le polymère conducteur PEDOT:PSS intégré dans des dispositifs électriques pour la caractérisation de barrières tissulaires. Ainsi, les transistors organiques électrochimiques (OECTs) ont été adaptés pour le développement de plateformes de caractérisation de sphéroïdes, de modèles tissulaires à l’interface air-liquide ou encore de réseaux vasculaires. Le lyophilisation du PEDOT :PSS a également permis la création d’un échafaudage 3D offrant de nouvelles perspectives pour le mélange de polymères électriquement actifs avec la matrice extracellulaire des tissus
In vitro cell models are widely accepted platforms for toxicological studies. However starting from the 2D models, improvements are needed to reproduce the physiological environment of the tissue. Advances in tissue engineering have given rise to 3D barrier tissue models that recreate cell-cell and cell-matrix interactions. However, electrical platforms to quantify barrier tissue permeability hasn’t followed the rapid pace of models complexification. In this work I explore the possibilities to design conductive polymer-based devices adapted for the characterization of barrier tissue models. Conventional electrical tools used to evaluate integrity of barrier tissues are made of metal electrodes placed on each side of the tissue. This technology presents limitations when it comes to analyzing customized 3D tissue models due to issues in electrode size and stiffness. As an alternative option to metal electrodes, organic electronic materials have shown great promise to interface with biological tissues. In particular the Organic ElectroChemical Transistor (OECT) using PEDOT:PSS has already shown great efficiency to quantify electrical properties of barrier tissues in 2D. Thanks to microfabrication techniques they can be miniaturized and tuned to form mechanically compliant interface with a range of biological tissues. In this thesis, OECT compatibility with models such as tracheal cell culture at the air-liquid interface, spheroid models and microvessel-on-a-chip system has been tested. The achievements described in this work present significant progress in the field of in vitro platforms of barrier tissue modeling for toxicology and drug discovery testing
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10

Mariani, Federica. "PEDOT:PSS thin films: Applications in Bioelectronics." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11915/.

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Анотація:
Owing to their capability of merging the properties of metals and conventional polymers, Conducting Polymers (CPs) are a unique class of carbon-based materials capable of conducting electrical current. A conjugated backbone is the hallmark of CPs, which can readily undergo reversible doping to different extents, thus achieving a wide range of electrical conductivities, while maintaining mechanical flexibility, transparency and high thermal stability. Thanks to these inherent versatility and attracting properties, from their discovery CPs have experienced incessant widespread in a great plethora of research fields, ranging from energy storage to healthcare, also encouraging the spring and growth of new scientific areas with highly innovative content. Nowadays, Bioelectronics stands out as one of the most promising research fields, dealing with the mutual interplay between biology and electronics. Among CPs, the polyelectrolyte complex poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS), especially in the form of thin films, has been emphasized as ideal platform for bioelectronic applications. Indeed, in the last two decades PEDOT:PSS has played a key role in the sensing of bioanalytes and living cells interfacing and monitoring. In the present work, development and characterization of two kinds of PEDOT:PSS-based devices for applications in Bioelectronics are discussed in detail. In particular, a low-cost amperometric sensor for the selective detection of Dopamine in a ternary mixture was optimized, taking advantage of the electrocatalytic and antifouling properties that render PEDOT:PSS thin films appealing tools for electrochemical sensing of bioanalytes. Moreover, the potentialities of this material to interact with live cells were explored through the fabrication of a microfluidic trapping device for electrical monitoring of 3D spheroids using an impedance-based approach.
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11

Mårtensson, Oskar. "LHCb Upstream Tracker box : Thermal studies and conceptual design." Thesis, Umeå universitet, Institutionen för fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-116163.

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Анотація:
The LHC (Large Hadron Collider) will have a long shut down in the years of 2019 and 2020, referred to as LS2. During this stop the LHC injector complex will be upgraded to increase the luminosities, which will be the first step of the high luminosity LHC program (which will be realized during LS3 that takes place in 2024-2026). The LHCb experiment, whose main purpose is to study the CP-violation, will during this long stop be upgraded in order to withstand a higher radiation dose, and to be able to read out the detector at a rate of 40MHz,compared to 1MHz at present. This change will improve the trigger efficiency significantly. One of the LHCb sub-detectors the Trigger Tracker (TT), will be replaced by a new sub-detector called UT. This report presents the early stage design (preparation for mock-up building) of the box that will be isolating the new UT detector from the surroundings and to ensure optimal detector operation. Methods to fulfill requirements such as light and gas tightness, Faraday-cage behavior and condensation free temperatures, without breaking the fragile beryllium beam pipe, are established.
LHC (Large Hadron Collider) kommer under åren 2019-2020 att ha ett längre driftstopp. Under detta driftstopp så kommer LHC's injektionsanordningar att uppgraderas för att kunna sätta fler protoner i circulation i LHC, och därmed öka antalet partikelkollisioner per tidsenhet. Denna uppgradering kommer att vara första steget i "High Luminocity LHC"-programmet som kommer att realiseras år 2024-2026. LHCb-experimentet, vars främsta syfte är att studera CP-brott, kommer också att uppgraderas under stoppet 2019-2020. Framför allt så ska avläsningsfrekvensen ökas från dagens 1MHz till 40MHz, och experimentet ska förberedas för de högre strålningsdoser som kommer att bli aktuella efter stoppet 2024-2026. En av LHCb's deldetektorer, TT detektorn, kommer att bytas ut mot en ny deldetektor som kallas UT. Den här rapporten presenterar den förberedande designen av den låda som ska isolera UT från dess omgivning och försäkra optimala förhållanden för detektorn. Kraven på den isolerande lådan och tillvägagångssätt för att uppfylla dessa krav presenteras.
LHCb, LS2 and LS3 Upgrade
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12

Lee, Wei-De, and 李維德. "A study of Graphene/polylactic acid conductive polymer 3D printing plating stent." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/puk6bd.

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Анотація:
碩士
國立虎尾科技大學
材料科學與工程系材料科學與綠色能源工程碩士在職專班
106
Electroplating technology is widely applied in various industries. For example, increasing the strength of metal surfaces, whether mechanical or chemical or physical, can be significantly helped by special processing on plastic materials. In general, a plating rack is used to connect electrode and plating. The main requirements of the performance of the hanger are sufficient mechanical strength, good electrical conductivity and non-corrosive materials. Electroplating large or mass production of plating, there will be hanged hanging rack for electroplating process. For small quantities or special shape plating, a special hanger must be designed to meet the electroplating requirements. But to meet such a special request of designing hanging, there will be a cost concern and difficulties of processing on unique shape occur. For consideration for above two issues, to find a way to proceed on the experiment in order to avoid the production of special shape, cost issue and the requirements of intensity and electric conduction. 3D printing is a competitive industry in recent years. Almost all kinds of shapes imaginable or impossible to be completed before can be produced through 3D printing now. In this experiment, smaller or more complex designed hangers are made through 3D printing and coated with grapheme on the surface to increase its mechanical properties and electrical conductivity and corrosion resistance. Graphene is a great discovery. It is a kind of hexagonal honeycomb lattice plane film composed of sp2 hybrid orbitals. Graphene is essentially a kind of transparent and good conductor. It is suitable to be used for creating a transparent touch screen, light panels, and even solar cells. In order to obtain graphene film successfully, a patent of Hefei University of Technology in China is referred to (a method of preparing graphene film by electroplating deposition method). Using a small amount of graphene oxide mixed with methanol and water at a proper ratio, using a graphene oxide solution as a plating solution, a positive electrode using a 3D printing rack, and a negative electrode using a stainless steel plate, using a plating principle, graphene oxide was coated on a hanger with 3D printing design, and then the graphene coating was tested and analyzed. Plating on the graphene attached to the conductive properties and not much difference in the surface of the apparent coating, as part of the surface temperature rise higher temperature, corrosion resistance slightly enhanced.
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13

CHEN, YI-SHIN, and 陳奕信. "The Study of Water-based catalyst polymer ink Applied to Conductive Patterns onto 3D Structures Process." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/52916736392270574113.

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Анотація:
碩士
國防大學理工學院
化學工程碩士班
105
By the five-axis drawing machine and the fountain pen, this study used water-based catalyst polymer ink to draw 3D stereoscopic substrate on the production of metal line graphics to plot the catalyst graph on the three-dimensional substrate surface. The temperature-sensitive nano-noble metal particles (Poly (St-NIPAAm) / Pd) catalyst ink is printed on a three-dimensional substrate followed by electroless plating to form the metallic pattern lines. In the electroless plating bath due to temperature increase concluded in a Phase change Produce hydrophobic character. The noble metal particles and the substrate between the high adhesion successed by electroless plating to form the metallic pattern. The 3D printer remodels into a five-axis plotter so that it can use fountain pen nib to deposit it on the surface via a combination of gravity and capillary action and draw the catalyst graph on the surface of the stereo substrate in the three-dimensional structure Curved or flat operation. To show the applicability of the process, nibs EF0.3mm applying a drawing speed of 5000mm / min control nibs with the substrate contact angle of less than 90 ° ∓ 10 ° and thicken the ink add associative polyurethane PU 5 wt% was used. We have a Fused Deposition Modeling(FDM) surface modification of the substrate using sandblasting and chloroform to modify the surface and gained a better parameter for the fountain pen. Therefore made a semi-circular model with a three-dimensional line and the line pattern resistance is about 0.351Ω / sq.m.This study successfully used low temperature and low cost to produce a conductive metal line on a three-dimensional substrate.
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14

Chuang, Fan-Yi, and 莊凡逸. "Study on Preparation and Characterization of Conductive Composite for 3D Printing via In Situ Generation of Low Silver Nanoparticles Amount in Photosensitive Polymer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/b63y53.

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Анотація:
碩士
國立中興大學
化學工程學系所
107
Three-dimensional (3D) printing has rapidly emerged. It has many advantages, such as customization, high speed processing, raw materials reduction and manufacture of complex 3D structures. A lot of researches report that the addition of nanomaterials has improved the properties of objects. In recent years, the development of electronics industry has been respected for 3D printing, such as wearable electronic device, sensor, super capacitor and printed circuit board. However, polymer was an insulator, which can increase the conductivity and mechanical properties by adding conductive filler. Therefore, the purpose of this study aims to design a photocurable formulation and in situ synthesis of metal nanoparticles during photopolymerization for 3D printing. In this study, we probe into the effect of properties on adding silver nitrate (AgNO3) into the 3D objects. Polyethylene glycol diacrylate was used as monomer. Phenyl-bis(2,4,6-trimethylbenzoyl)-phosphine oxide (BAPO) was used as photoinitiator. In addition, pyrrole was used as solvent in preparation for the experiment. The in situ generated silver nanoparticles for 3D printing process and investigated different concentration of AgNO3 about properties on 3D objects. Using field emission scanning electron microscope (FESEM), thermogravimeteric analysis (TGA), dynamic mechanical analyzer (DMA) and four point probe tester. The results showed that the silver nanoparticles were successfully reduced and dispersed in the 3D objects. Mean particle size of as-synthetized silver by photopolymerization was about 35.5 nm, degradation temperature (Td) of 3D objects was 394.0 ℃, storage modulus was 0.87 GPa and sheet resistance value obviously decreased to 2.9 x 105 Ω/sq for 5 wt% loading of silver nanoparticles. It means that the presence of silver nanoparticles in the object brings the improvement of thermal resistance, mechanical properties and electrical conductivity.
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15

Cheng, Ming-Hsu, and 鄭名栩. "3D Printed Cassette Embedded with Conductive Polymer Electrodes for Two-Dimensional Paper Chromatography and Paper Spray Mass Spectrometry (PS-MS) Detection in Bioanalysis and Food-safety Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3pt92f.

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Анотація:
碩士
國立中山大學
機械與機電工程學系研究所
106
This paper presents a novel paper-based microfluidic cassette integrated two-dimensional paper chromatography and paper spray mass spectrometry (PS-MS) detection in bioanalysis and food-safety applications. The cassette can be fabricated in a single-process through a dual-extrusion 3D printer equipped with ABS and ABS conductive polymers such that delicate fabrication processes can be excluded for producing the cassette. The sample injection, separation, concentration and electrospray ionization could be completed in the single microfluidic cassette through the specially designed cassette, paper-based microfluidic and the embedded polymer electrode. The liquid sample is directly applied to the sample trench and then separated and concentrated using a 2D paper chromatography technique. To further improve the performance of the paper-based microfluidic system, several special designs including a tip contact for uniform developing solution dispersion, several sacrificial wings for sample smear elimination and sculpted holes for electrical isolation during paper spray ionization. Results shows that the sacrificial wing and throttle valve can increase the number of theoretical plate to about 3.9 and 1.6 times respectively in the first-dimensional chromatography, and greatly reduce the sample residue on the paper tip. The second-dimensional chromatography has increased the signal strength by nearly a hundred times. The developed system can detect the residual pesticides in fresh grape, and the residual drug in body fluid.
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