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Uma análise do ethos no discurso publicitário da L'Oréal ParisBlasques, Fernanda 08 February 2007 (has links)
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Previous issue date: 2007-02-08 / The research here developed has had the intention of showing the build up of the ethos in the advertising speech of L Oréal through the analysis of advertising pieces propagated in the printed media in the year 2006.Studied since Aristotle s Rhetoric until our times through the Speech Analysis and authors as Maingueneau and Charaudeau, the ethos takes part into the formation of the enunciative scene, also built by aspects the place and time of the articulation, social condition of the speaker and the listener of the message and the situation in which the speech is being produced. As the ethos is the voice of the speech, it makes interdependent all the other relevant elements for the building of the scene. To achieve the objective, we start by pointing out the definition and presentation of concepts referring to the Speech Analysis (more specifically about the ethos) according to the works of Charaudeau (2006) e Maingueneau (1997, 1999 e 2002), and to aspects of the advertising language according to Carvalho (2003), Carrascoza (2003) and Priore (2000). The considerations about Ideology retake authors as Althusser (1998), Bakhtin (1990) and Neto (1999); theoretic aspects about ethos, rhetoric and persuasion in the works of Aristóteles (199_ e 2000),
Maingueneau e Charaudeau. In the analysis, the advertisings were described in their image aspects; after that, they were studied in relation to their speech and ideological formation, and, finally, according to the message transmitted by the speaker of the ethos. As the result, it was verified that, independently of the product
announced or the kind of public to be achieved by the speech of the speaker, the same ethos is kept trying to offer the consumers something that may be able to resolve an important problem for the modern women: the necessity of eternal beauty and youth, which are values imposed by the current Ideology. For this to be possible, the speaker of the ethos of L Oréal Paris uses famous models (who posses the values desired for modern women) to give authority to the advertisings. So the ethos suggests always that common women can also become beautiful and young as the stars in the ads. / A pesquisa aqui desenvolvida procurou demonstrar a construção do ethos no discurso publicitário da L Oréal por meio da análise de quatro peças publicitárias veiculadas na mídia impressa no ano de 2006. Estudado desde a Retórica aristotélica até os dias de hoje por meio da Análise do Discurso e de autores como Maingueneau e Charaudeau, o ethos participa da formação da cena enunciativa, também construída por aspectos como local e tempo da enunciação, condições sociais do locutor e receptor da mensagem e a situação na qual o discurso está sendo produzido. Sendo o
ethos a voz do discurso, ele torna todos os elementos relevantes para a formação da cena enunciativa interdependentes. Para atingir o objetivado, partimos de considerações acerca da Análise do Discurso de linha francesa (mais especificamente a questão do ethos), segundo Maingueneau (1997, 1999 e 2002) e Charaudeau (2006) e de aspectos da linguagem publicitária de acordo com Carvalho (2003), Carrascoza (2003) e Priore (2000). As considerações sobre ideologia e mídia retomam Bakthin (1990), Althusser (1998) e Neto (1999). Na análise, as propagandas foram descritas quanto aos aspectos imagéticos; em seguida, estudadas em relação às formações discursivas e ideológicas e, por fim, quanto à mensagem transmitida pelo locutor do ethos. Como resultado, verificou-se que, independentemente do produto anunciado ou do tipo de público a ser atingido pelo discurso do locutor, o ethos se mantém o mesmo sempre buscando oferecer às consumidoras algo que poderá sanar um grande problema da mulher moderna, a necessidade da beleza e juventude eternas , que são valores impostos pela ideologia
corrente. Para tanto, o enunciador do ethos de L Oréal Paris recorre a modelos famosas (e que possuem os valores ideológicos almejados pelas mulheres modernas) para dar autoridade às propagandas. Deste modo, o ethos sugere que mulheres comuns também podem vir a ser belas e jovens como as estrelas dos anúncios.
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Desenvolvimento de um biossensor mimético descartável para pesticidas organofosforados e carbamatos para o controle de qualidade de águas de abastecimento / Development of a disposable mimetic biosensor for organophosphorus and carbamate pesticides aiming quality control of water supplyLívia Flório Sgobbi 26 February 2016 (has links)
A enzima acetilcolinesterase (AChE) tem sido amplamente aplicada no desenvolvimento de biossensores para detecção de pesticidas. No entanto, a aplicação de tais dispositivos é limitada devido à falta de robustez, que está associada com a baixa estabilidade enzimática, além de seu alto custo. Uma alternativa às enzimas é a utilização de moléculas sintéticas que mimetizem o comportamento enzimático, com menor custo e maior estabilidade; tais moléculas são denominadas moléculas biomiméticas. Neste trabalho são apresentados três potenciais catalisadores: o ácido [4-(1E)etanohidrazonoil]benzóico, o iodeto de pralidoxima (2-PAM) e o polímero polihidroxamicalcanoato (PHA); com grupos funcionais alfa nucleófilos hidrazona, oxima e ácido hidroxâmico, respectivamente. Tais moléculas foram avaliadas baseando-se em dois critérios para classificação de biomiméticos da AChE: 1) catálise da hidrólise do substrato acetiltiocolina (ATCh) e 2) interação com pesticida organofosforado. O método espectrofotométrico de Ellman revelou que o polímero PHA foi a molécula mais eficiente, uma vez que a constante de velocidade de segunda ordem obtida foi de 13867 mol-1 L s-1, 5 vezes superior a da 2-PAM e 232 vezes a da hidrazona. Posteriormente, todas as moléculas foram avaliadas por método espectrofotométrico em relação à interação com o organofosforado paraoxon. Apenas o PHA apresentou interação nas condições estudadas. Cálculos teóricos mostraram como ocorre a aproximação entre o PHA e ATCh, e com o paraoxon. Diante dos resultados obtidos, o PHA foi a molécula biomimética escolhida para aplicação no sensor eletroquímico para detecção de organofosforados. Primeiramente, o PHA foi imobilizado na superfície de um eletrodo impresso descartável a partir da formação de uma blenda com o polímero polietileno glicol metil éter, evitando sua solubilização. A oxidação da tiocolina formada a partir da catálise do ATCh realizada pelo PHA imobilizado foi verificada em 0,46 V vs Ag/AgCl, por voltametria de pulso diferencial. A equação obtida a partir da curva de calibração referente ao intervalo de concentração de paraoxon de 1,0 a 10,0 µmol L-1 foi I(%) = [4,8x106 C (mol L-1) + 0,8169]×100 (R2 = 0,99969), com limite de detecção de 3,63x10-7 mol L-1. Amostras de água de abastecimento foram analisadas, com concentrações adicionadas de paraoxon de 3,0; 6,0 e 8,0 µmol L-1, com recuperação de 115%; 106% e 94,5%, respectivamente. Os resultados apresentados mostraram que foi possível desenvolver um sensor eletroquímico biomimético para detecção de pesticida paraoxon. / Acetylcholinesterase enzyme (AChE) has been widely applied in biosensor development for pesticide detection. However, the application of those biosensors is limited due to their lack of robustness associated with low enzymatic stability and AChE high cost. An alternative to enzymes, it is the use of synthetic molecules which mimic enzymatic behavior, besides its low cost and superior stability, those are classified as biomimetic molecules. In this work is presented three potential catalysts: [4-(1E)ethanehydrazonoyl]benzoic acid, pralidoxime iodide (2-PAM), and polyhydroxamicalkalnoate polymer (PHA) with alpha nucleophile functional groups, such as hydrazone, oxime, and hydroxamic acid, respectively. The aforementioned molecules were evaluated based on two criteria for classification as AChE biomimetic: 1) catalysis of acetylthiocholine substrate (ATCh) hydrolysis and 2) interaction with organophosphorus pesticide. Spectrophotometrical Ellman´s method revealed that PHA polymer was the most efficient one, since its second order rate constant was 13867 mol-1 L s-1, which was 5 times superior than 2-PAM one and 232 times higher than hydrazone. Then, each molecule was analyzed through spectrophotometric method to verify the interaction with paraoxon organophosphorus pesticide. Only the PHA exhibited such interaction in the studied conditions. Theoretical calculations showed how the approach between PHA and ATCh, and also with paraoxon occurred. Regarding the obtained results, PHA was the chosen biomimetic molecule to be applied in the electrochemical sensor for organophosphorus detection. First of all, PHA was immobilized on the surface of disposable screen printed electrode through blend formation with polyethylene glycol methyl ether (mpEG), avoiding PHA dissolution. The oxidation of thiocholine generated towards ATCh catalysis performed by immobilized PHA was verified at 0.46 V vs Ag/AgCl by differential pulse voltammetry. The linear equation obtained through calibration curve for paraoxon concentration range of 1.0 to 10.0 µmol L-1 was I(%) = [4.8x106 C (mol L-1) + 0.8169]×100 (R2 = 0.99969), with limit of detection of 3.63x10-7 mol L-1. Water supply samples were analyzed considering the added paraoxon concentrations of 3.0; 6.0 e 8.0 µmol L-1, recovering 115%; 106% and 94.5%, respectively. The presented results showed that a biomimetic electrochemical sensor was successfully developed for detection of paraoxon organophosphorus pesticide.
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Antenas para sistemas RFID impressas em substrato flexível. / Antennas for RFID systems printed on flexible substrate.Valmiro, Robson 12 February 2015 (has links)
Identificação de Dispositivos por Radiofrequência, do inglês, Radio Frequency Identification Device (RFID), é uma tecnologia para identificação, rastreamento e gerenciamento de produtos, animais e até mesmo pessoas sem a necessidade de um campo visual. Com o objetivo de alcançar custos menores e a utilização de processos de fabricação menos agressivo ao meio ambiente, tornou-se importante o desenvolvimento de novos tipos de etiquetas (tags). Em vista disso, a fabricação de antenas impressas compactas usando tinta condutiva, representa uma boa opção. O objetivo dessa pesquisa é o projeto e fabricação de antenas impressas sobre substratos flexíveis utilizando tinta condutiva composta de nanopartículas de prata. O desenvolvimento deste tipo de etiquetas é justificado principalmente pelos seguintes motivos. Primeiro, o processo reduz o uso de agentes químicos comumente empregados na fabricação convencional, levando a uma significativa redução no impacto ambiental. Segundo, a fabricação utilizando substratos como, por exemplo, papel ou polímero, reduz substancialmente o custo final da etiqueta. Estudos teóricos e práticos, juntamente com simulações eletromagnéticas foram realizados. Dois processos de prototipagem da etiqueta foram executados: um utilizando uma impressora jato de tinta que funciona propelindo gotas de tinta sobre o substrato e o outro utilizando serigrafia ou silkscreen printing que é muito prático para imprimir formas geométricas através de uma tela de fios trançados. Esses métodos de impressão permitiram a produção rápida da antena sem a necessidade de máscaras de fotolitografia, como é amplamente utilizado na indústria eletrônica. Quatro protótipos foram produzidos e medidas foram realizadas para verificar a viabilidade da utilização dessas etiquetas impressas em relação à sua operação, a confiabilidade das informações armazenadas e a troca de dados com o leitor RFID via interface aérea. Os resultados práticos foram comparados com os obtidos de etiquetas comerciais, onde foi possível verificar que a antena fabricada com tinta condutiva é capaz de capturar e radiar ondas eletromagnéticas de forma eficiente, resultando em uma troca de dados confiáveis através da interface aérea. / Radio Frequency Identification Device (RFID), it is a technology using electromagnetic waves for identifying, tracking and management of products, animals and even people without requiring a visual field. Aiming at achieving low costs and using less aggressive manufacturing processes to the environment, it has become important to develop new types of RFID tags. In view of that, manufacturing compact printed antennas using conductive ink represents a good option. The goal of this research is the design of printed antennas on flexible substrates using silver nanoparticles ink. The developing of this type of tags is justified mainly by the following reasons. First, the process reduces the use of chemical agents commonly employed in conventional manufacturing leading to a significant reduction of the environmental impact. Second, the fabrication using substrates such as paper and polymer foils, substantially reduces the final cost of the tags. Theoretical and practical studies along with electromagnetic simulations were conducted. Two process of RFID prototyping were performed: one using an inkjet printer that operates by propelling particles of conductive ink onto the substrate and another using silkscreen printing that is a very practical method to print geometric forms through a twisted wires screen. These technologies allowed fast production of the antenna without requiring photolithographic masks, as it is widely used in the electronics industry. Four prototypes were produced and measurements were taken to verify the feasibility of using RFID tags printed with conductive ink regarding to its operation, reliability of the stored information and the exchange of data with the RFID reader via air interface. Practical results were compared with those obtained of the commercial tags. It was possible to verify that the antenna manufactured with conductive ink was able to capture and radiate efficiently electromagnetic waves, resulting in reliable exchange of data with the reader through the air interface
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Desenvolvimento de um biossensor mimético descartável para pesticidas organofosforados e carbamatos para o controle de qualidade de águas de abastecimento / Development of a disposable mimetic biosensor for organophosphorus and carbamate pesticides aiming quality control of water supplySgobbi, Lívia Flório 26 February 2016 (has links)
A enzima acetilcolinesterase (AChE) tem sido amplamente aplicada no desenvolvimento de biossensores para detecção de pesticidas. No entanto, a aplicação de tais dispositivos é limitada devido à falta de robustez, que está associada com a baixa estabilidade enzimática, além de seu alto custo. Uma alternativa às enzimas é a utilização de moléculas sintéticas que mimetizem o comportamento enzimático, com menor custo e maior estabilidade; tais moléculas são denominadas moléculas biomiméticas. Neste trabalho são apresentados três potenciais catalisadores: o ácido [4-(1E)etanohidrazonoil]benzóico, o iodeto de pralidoxima (2-PAM) e o polímero polihidroxamicalcanoato (PHA); com grupos funcionais alfa nucleófilos hidrazona, oxima e ácido hidroxâmico, respectivamente. Tais moléculas foram avaliadas baseando-se em dois critérios para classificação de biomiméticos da AChE: 1) catálise da hidrólise do substrato acetiltiocolina (ATCh) e 2) interação com pesticida organofosforado. O método espectrofotométrico de Ellman revelou que o polímero PHA foi a molécula mais eficiente, uma vez que a constante de velocidade de segunda ordem obtida foi de 13867 mol-1 L s-1, 5 vezes superior a da 2-PAM e 232 vezes a da hidrazona. Posteriormente, todas as moléculas foram avaliadas por método espectrofotométrico em relação à interação com o organofosforado paraoxon. Apenas o PHA apresentou interação nas condições estudadas. Cálculos teóricos mostraram como ocorre a aproximação entre o PHA e ATCh, e com o paraoxon. Diante dos resultados obtidos, o PHA foi a molécula biomimética escolhida para aplicação no sensor eletroquímico para detecção de organofosforados. Primeiramente, o PHA foi imobilizado na superfície de um eletrodo impresso descartável a partir da formação de uma blenda com o polímero polietileno glicol metil éter, evitando sua solubilização. A oxidação da tiocolina formada a partir da catálise do ATCh realizada pelo PHA imobilizado foi verificada em 0,46 V vs Ag/AgCl, por voltametria de pulso diferencial. A equação obtida a partir da curva de calibração referente ao intervalo de concentração de paraoxon de 1,0 a 10,0 µmol L-1 foi I(%) = [4,8x106 C (mol L-1) + 0,8169]×100 (R2 = 0,99969), com limite de detecção de 3,63x10-7 mol L-1. Amostras de água de abastecimento foram analisadas, com concentrações adicionadas de paraoxon de 3,0; 6,0 e 8,0 µmol L-1, com recuperação de 115%; 106% e 94,5%, respectivamente. Os resultados apresentados mostraram que foi possível desenvolver um sensor eletroquímico biomimético para detecção de pesticida paraoxon. / Acetylcholinesterase enzyme (AChE) has been widely applied in biosensor development for pesticide detection. However, the application of those biosensors is limited due to their lack of robustness associated with low enzymatic stability and AChE high cost. An alternative to enzymes, it is the use of synthetic molecules which mimic enzymatic behavior, besides its low cost and superior stability, those are classified as biomimetic molecules. In this work is presented three potential catalysts: [4-(1E)ethanehydrazonoyl]benzoic acid, pralidoxime iodide (2-PAM), and polyhydroxamicalkalnoate polymer (PHA) with alpha nucleophile functional groups, such as hydrazone, oxime, and hydroxamic acid, respectively. The aforementioned molecules were evaluated based on two criteria for classification as AChE biomimetic: 1) catalysis of acetylthiocholine substrate (ATCh) hydrolysis and 2) interaction with organophosphorus pesticide. Spectrophotometrical Ellman´s method revealed that PHA polymer was the most efficient one, since its second order rate constant was 13867 mol-1 L s-1, which was 5 times superior than 2-PAM one and 232 times higher than hydrazone. Then, each molecule was analyzed through spectrophotometric method to verify the interaction with paraoxon organophosphorus pesticide. Only the PHA exhibited such interaction in the studied conditions. Theoretical calculations showed how the approach between PHA and ATCh, and also with paraoxon occurred. Regarding the obtained results, PHA was the chosen biomimetic molecule to be applied in the electrochemical sensor for organophosphorus detection. First of all, PHA was immobilized on the surface of disposable screen printed electrode through blend formation with polyethylene glycol methyl ether (mpEG), avoiding PHA dissolution. The oxidation of thiocholine generated towards ATCh catalysis performed by immobilized PHA was verified at 0.46 V vs Ag/AgCl by differential pulse voltammetry. The linear equation obtained through calibration curve for paraoxon concentration range of 1.0 to 10.0 µmol L-1 was I(%) = [4.8x106 C (mol L-1) + 0.8169]×100 (R2 = 0.99969), with limit of detection of 3.63x10-7 mol L-1. Water supply samples were analyzed considering the added paraoxon concentrations of 3.0; 6.0 e 8.0 µmol L-1, recovering 115%; 106% and 94.5%, respectively. The presented results showed that a biomimetic electrochemical sensor was successfully developed for detection of paraoxon organophosphorus pesticide.
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Nontraditional amorphous oxide semiconductor thin-film transistor fabricationSundholm, Eric Steven 11 September 2012 (has links)
Fabrication techniques and process integration considerations for amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) constitute the central theme of this dissertation. Within this theme three primary areas of focus are pursued.
The first focus involves formulating a general framework for assessing passivation. Avoiding formation of an undesirable backside accumulation layer in an AOS bottom-gate TFT is accomplished by (i) choosing a passivation layer in which the charge neutrality level is aligned with (ideal case) or higher in energy than that of the semiconductor channel layer charge neutrality level, and (ii) depositing the passivation
layer in such a manner that a negligible density of oxygen vacancies are present at the channel-passivation layer interface. Two AOS TFT passivation schemes are explored. Sputter-deposited zinc tin silicon oxide (ZTSO) appears promising for suppressing
the effects of negative bias illumination stress (NBIS) with respect to ZTO and IGZO TFTs. Solution-deposited silicon dioxide is used as a barrier layer to subsequent PECVD silicon dioxide deposition, yielding ZTO TFT transfer curves showing that the dual-layer passivation process does not significantly alter ZTO TFT
electrical characteristics.
The second focus involves creating an adaptable back-end process compatible with flexible substrates. A detailed list of possible via formation techniques is presented with particular focus on non-traditional and adaptable techniques. Two of the
discussed methods, "hydrophobic surface treatment" and "printed local insulator," are demonstrated and proven effective.
The third focus is printing AOS TFT channel layers in order to create an adaptable and additive front-end integrated circuit fabrication scheme. Printed zinc indium aluminum oxide (ZIAO) and indium gallium zinc oxide (IGZO) channel layers are demonstrated using a SonoPlot piezoelectric printing system.
Finally, challenges associated with printing electronic materials are discussed. Organic-based solutions are easier to print due to their ability to "stick" to the substrate and form well-defined patterns, but have poor electrical characteristics due
to the weakness of organic bonds. Inorganic aqueous-based solutions demonstrate good electrical performance when deposited by spin coating, but are difficult to print because precise control of a substrate's hydrophillic/hydrophobic nature is required. However, precise control is difficult to achieve, since aqueous-based solutions either spread out or ball up on the substrate surface. Thickness control of any printed solution
is always problematic due to surface wetting and the elliptical thickness profile of a dispensed solution. / Graduation date: 2013
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Design of a Highly Constrained Test System for a 12-bit, 16-channel Wilkinson ADCPannell, Zachary William 01 December 2009 (has links)
Outer space is a very harsh environment that can cause electronics to not operate as they were originally intended. Aside from the extreme amount of radiation found in space, temperatures can also change very dramatically in a relatively small time frame. In order to test electronics that will be used in this environment, they first need to be tested on Earth under replicated conditions. Vanderbilt University designed a dewar that allows devices to be tested at these extreme temperatures while being radiated. For this thesis, a test setup that met all of the dewar's constraints was designed that would allow a 12-bit, 16-channel analog-to-digital converter to be tested while inside.
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Reintroducing Communication as a Strategy in Printed Evidence-based Medical Materials. Model to Assess EffectivenessGenova, Juliana 07 November 2012 (has links)
Hypotheses on the efficiency of evidence-based printed materials can be directed by health communication concepts. These concepts can provide a general framework that goes beyond the traditional vulgarization point of view: instead, it points towards a strategy to obtain health outcomes and provoke behavior change, from a disease prevention, management and health promotion perspective.
The present study proposes a comprehensive framework based on concepts from health risk communication, Tarde's theory of social values, usability, readability and plain language. Using the mapping approach, an evaluation grid was applied to printed evidence-based materials with proven effectiveness, in order to reveal the underlying strategy and isolate the characteristics of effective materials.
The results allowed us to define two types of printed evidence-based materials, according to the robustness of the evidence they contain and the target audience. It was also possible to identify indicators of notions that are translated into operationalized items, frequent in those materials that might be responsible for their efficiency: clear purpose of the documents, limited scope, learning motivation and correspondence to the logic, experience and language of readers. Effectiveness of printed evidence-based materials could also be correlated to numeracy, objectiveness, standard definitions, constant timeframes and denominators, risks enumerated in order of importance, effective response, and high degree of threat, urgency, novelty and visibility of the disease.
It was also possible to identify some missing communication concepts: cultural diversity, narrative, increased easiness of procedures and aesthetic advantage for the patient.
In the process of work, the theory of social values emerged as a dynamic component that can bring together and explain many concepts, as well as physician’s acceptance of the guidelines. Value in terms of usefulness and truth plays a major role in cognitive appreciation of the documents. This concept gives a strategic meaning to the whole work and allows us to better understand attitude and behavior change.
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A Population-based Study on the Association of Standardized Protocols in the Emergency Department for Childhood Asthma with Outcomes in Ontario, CanadaLi, Patricia 10 January 2011 (has links)
Objectives: To describe the use of standardized protocols (SPs) in emergency departments (EDs) across Ontario for childhood asthma and analyze the association of SPs with hospital admissions, 7-day ED re-visits, and outpatient follow-up visits.
Methods: Population-based retrospective cohort study using health administrative data and survey data. EDs were categorized as having the optimal, other, or no SP for each outcome. Associations were tested with generalized estimating equations.
Results: Between 2006/04/14-2009/02/28, 46,510 children with asthma were seen in 146 EDs, with 43 (29.5%) having SPs. Children treated in EDs with the optimal SP compared to no SP had no significant differences in hospital admissions (AOR 1.17; 95% CI 0.91, 1.49) or ED re-visits (AOR 1.09; 95% CI 0.85, 1.40) but were more likely to have follow-up visits (AOR 1.27; 95% CI 1.02, 1.59).
Conclusions: SPs for childhood asthma are not common in Ontario EDs and had little impact on outcomes measured.
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A Population-based Study on the Association of Standardized Protocols in the Emergency Department for Childhood Asthma with Outcomes in Ontario, CanadaLi, Patricia 10 January 2011 (has links)
Objectives: To describe the use of standardized protocols (SPs) in emergency departments (EDs) across Ontario for childhood asthma and analyze the association of SPs with hospital admissions, 7-day ED re-visits, and outpatient follow-up visits.
Methods: Population-based retrospective cohort study using health administrative data and survey data. EDs were categorized as having the optimal, other, or no SP for each outcome. Associations were tested with generalized estimating equations.
Results: Between 2006/04/14-2009/02/28, 46,510 children with asthma were seen in 146 EDs, with 43 (29.5%) having SPs. Children treated in EDs with the optimal SP compared to no SP had no significant differences in hospital admissions (AOR 1.17; 95% CI 0.91, 1.49) or ED re-visits (AOR 1.09; 95% CI 0.85, 1.40) but were more likely to have follow-up visits (AOR 1.27; 95% CI 1.02, 1.59).
Conclusions: SPs for childhood asthma are not common in Ontario EDs and had little impact on outcomes measured.
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Highly conductive stretchable electrically conductive composites for electronic and radio frequency devicesAgar, Joshua Carl 05 July 2011 (has links)
The electronics industry is shifting its emphasis from reducing transistor size and operational frequency to increasing device integration, reducing form factor and increasing the interface of electronics with their surroundings. This new emphasis has created increased demands on the electronic package. To accomplish the goals to increase device integration and interfaces will undoubtedly require new materials with increased functionality both electrically and mechanically.
This thesis focuses on developing new interconnect and printable conductive materials capable of providing power, ground and signal transmission with enhanced electrical performance and mechanical flexibility and robustness. More specifically, we develop: 1.) A new understanding of the conduction mechanism in electrically conductive composites (ECC). 2.) Develop highly conductive stretchable silicone ECC (S-ECC) via in-situ nanoparticle formation and sintering. 3.) Fabricate and test stretchable radio frequency devices based on S-ECC. 4.) Develop techniques and processes necessary to fabricate a stretchable package for stretchable electronic and radio frequency devices.
In this thesis we provide convincing evidence that conduction in ECC occurs predominantly through secondary charge transport mechanism (tunneling, hopping). Furthermore, we develop a stretchable silicone-based ECC which, through the incorporation of a special additive, can form and sinter nanoparticles on the surface of the metallic conductive fillers. This sintering process decreases the contact resistance and enhances conductivity of the composite. The conductive composite developed has the best reported conductivity, stretchability and reliability. Using this S-ECC we fabricate a stretchable microstrip line with good performance up to 6 GHz and a stretchable antenna with good return loss and bandwidth.
The work presented provides a foundation to create high performance stretchable electronic packages and radio frequency devices for curvilinear spaces. Future development of these technologies will enable the fabrication of ultra-low stress large area interconnects, reconfigurable antennas and other electronic and RF devices where the ability to flex and stretch provides additional functionality impossible using conventional rigid electronics.
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