This dissertation presents the modeling, design, fabrication, and experimental testing of a polyimide based micro mirror for applications in MEMS logic devices based on its static behavior and in MEMS resonators using mixed frequency excitation. First, a universal MEMS logic device that can perform all the logic operations, such as INVERTER, AND, NAND, NOR, and OR gates using one physical structure, within an operating range of 0-10 volts. It can also perform XOR and XNOR with one access inverter using the same structure with different electrical interconnects. We discuss the fabrication, simulations and experimental results demonstrating these logic operations on a polyimide micro mirror. The device is capable of performing the switching operation with a frequency of 1 kHz, a switching time of 8.2 μs, and an electrical lifetime of 8000 cycles. Second, this study presents an experimental and theoretical investigation of a micro mirror under a mixed frequency signal composed of two harmonic AC sources. The experimental and theoretical dynamics are explored via frequency sweeps in the desired neighborhoods. One frequency is fixed while the other frequency is swept through a wide 5 range to study the dynamic responses of the micro mirror. These responses are studied under different frequencies and different input voltages. The results show interesting dynamics, where the system exhibits primary resonance, and combination resonances of additive and subtractive type. The mixed excitation is demonstrated as a way to increase the bandwidth of the resonator near primary resonance, which can be promising for resonant sensing applications in the effort to increase the signal-noise ratio over extended frequency range. It can be promising for energy harvesting as well; since it provides the system with resonances of very high amplitudes at very low frequencies regardless of what is the natural frequency of the system, however this still needs further investigation.

<p>Radiative cooling is an approach that utilizes the material reflectance in solar spectrum to reflect solar irradiation and emit the energy to deep space (2.7K) through the transparent portion in atmosphere (8-13μm). Therefore, radiative cooling is a passive cooling method that can generate a large reduction in energy consumption in the cooling sector. Scientists have been researching on the best solution for passive radiative cooling, including the utilization of multi-layer techniques with a metallic base layer. However, the current solutions are usually not cost effective and thus limited in the commercial applications. We initially started with the experiment on single-layer cooling paints embedded with TiO₂nanoparticles, and we were able to achieve a partial daytime radiative cooling effect of 60Wm^-2 Built upon our lab’s success of full-daytime sub-ambient cooling based on BaSO₄-acrylic paints, we experiment with colored cooling paints based on BaSO₄ nanoparticles instead of TiO₂ nanoparticles. Our results show much enhanced solar reflectance while matching the color, indicating the potential for colored cooling paints, although outdoor tests have not shown significant temperature drop compared to commercial colored paints yet. At the same time, we also explore creatures with shells in nature for possible solutions. Seashells are collected and the microstructures and radiative properties are characterized. The results provide insights into bio-inspired radiative cooling solutions.</p>

In the last decade, organic photovoltaics (OPV) have gained considerable attention with a rapid improvement of power conversion efficiency (PCE) from 5% to more than 13%. At the origin of the gradual efficiency improvements are (i) the rationalization of material design and (ii) systematic optimization of film processing condition. OPV can have a key role in markets such as building-integrated photovoltaics (BIPV). The main advantages of organic solar cells are semitransparency, low weight, good performance at low light intensity, flexibility and potential low-cost module manufacture through solution processed-based technologies. In solution processed OPV, the active layer that converts photons into electric charges is a composite of two organic compounds, a donor (D) and an acceptor (A) where the best morphology is achieved via the so-called bulk heterojunction (BHJ): an interpenetrating phase-separated D-A network. Historically, research has been focused on polymer donors and guidelines about morphology and film processing have been established. However recent studies have shown that small-molecule (SM) donors can rival their polymer counterparts in performance. The advantages of SM are a defined molecular weight, the ease of purification and a good batch-to-batch reproducibility. Using this class of material the existing guidelines have to be adjusted and refined. In this dissertation, using new SM synthesized in our laboratory, solution-processed organic solar cells are fabricated in which the morphology of the active layer is controlled by thermal annealing, the use of additive or solvent vapor annealing. In-depth analyses of the morphology are correlated to charge generation, recombination and extraction inferred from device physics. In the first part of the dissertation, using a small amount of 1,8-Diiodooctane additive that acts as a plasticizer, it is found that the D-A domains do not necessarily need to be pure and that mixed domains can also result in high performing devices. In the second part of the dissertation, the effect of solvent vapor annealing, particularly effective for SM:PCBM BHJ, is discussed where excellent control of the morphology is achieved. In the last part of the dissertation, efficient organic solar cells with open circuit voltage of >1.05V are made via fine-tuning of the morphology.

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Based on binocular vision the human eye is capable of generating the observed spatial perception of the object. Nowadays 3D imaging of two-dimensional surface is in vogue especially in the cinema industry. However, 3D imaging is gradually getting into other industries especially in other parts of everyday life (advertisements, presentations, entertainment ...). 3D images can be created in various ways, some of which are detailed in this master´s thesis. This thesis deals with the description and the drawing up of a 3D display which provides a three-dimensional image without using auxiliary objects such as glasses. The display unit produces a three-dimensional image at a fundamental level, which consists of providing high-speed rotation of the display and creates the current portion of the object in specified sections.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this research paper, we proposed an extended model for the early detection of skin cancer... The purpose is reduce the waiting time to obtaining a diagnosis, in addition, the function of the dermatoscope has been digitized by using a Smartphone and magnifying lenses as an accessory the mobile device. The proposed model has five phases: 1. The patient is attended by a general practitioner or nurse previously trained in any health center which has WiFi or mobile network connectivity to record their data and capture the skin lesion that will be analyzed. 2) The image will be in the cloud storage, which at the same time feeds an exclusive access website of dermatologists.3) Images are analyzed in real time using an image recognition service provided by IBM, which is integrated into a cloud-hosted web platform and an-Android application. 4)The result of the image processing is visualized by the dermatologist who makes a remote diagnosis.5) This diagnosis is received by the general practitioner or nurse, responsible for transmitting the diagnosis and treatment to the patient. This model was validated in a group of 60 patients, where 28 suffer from skin cancer in the early stage, 12 in the late stage and 20 are healthy patients, in a network of clinics in Lima, Peru. The obtained result was 97.5% of assertiveness on the analyzed skin lesions and 95% in healthy patients. / Revisión por pares

In recent years super-hydrophobic micro-patterned substrates (SHS) have been successfully used for the suspension of a few biological molecules, allowing the further characterization in a background-free environment by label-free techniques such as Raman spectroscopy, SEM and TEM in one device. This result is due to the combined action of laminar flow and shear stress exerted on the molecules contained in a drop that is spotted on top of the SHS and slowly evaporates. This new method is here proposed for the label-free formation and background-free characterization of amyloid fibers. Amyloids are insoluble aggregates formed by proteins that convert from a misfolded form into highly-organized β-sheet structures that could accumulate in different organs and compromise their normal physiological functions. Known amyloid-related diseases, named amyloidosis, are for instance Alzheimer, Parkinson, and type 2 diabetes. In classical crystallography, the study of the amyloid aggregates structure is often hampered by the laborious and time consuming sample preparation techniques. Therefore the need of a quick reproducible technique, has emerged. The amyloid fibers investigated in this work are derived from a lysozyme protein and a Tau-derived short peptide, both known to be related to two forms of amyloidosis. With this technique we demonstrate that threads of protein fibers are deposited on the substrate helped by the patterning of the SHS and its properties, and by characterizing them with Raman spectroscopy technique we revealed that they are anisotropic structures of amyloid nature. This type of sample preparation technique arises from the effect of the evaporation on the SHS, and opens up new possibilities for the formation of oriented fibers of amyloids and more in general, of proteins, ready for a substrate-free characterization, while classic crystallographic methods could have a limitation.

Cette thèse de doctorat, en Sciences de Gestion, a pour terrain de réflexions et d’actions de recherche, le projet WITE 2.0 consacré à l’analyse technico-organisationnelle d’un dispositif TIC en développement : une plateforme intégrée de télétravail. Cette plateforme permet de travailler «à distance» en mode connecté ou non, à partir de n’importe quel terminal (PC, téléphone, tablette), sur un mode «client léger» et dans un environnement de type cloud computing. De la conception de cette plateforme ont émergé des questionnements relatifs à la place des technologies d’information et de communication (TIC) dans les activités de travail réalisées «à distance» de son collectif de travail. Notre stratégie de recherche est constituée de deux grandes phases d’actions de recherche : la première consistait à connaître la diversité des configurations de «télétravail» et la seconde à comprendre les modes d’appropriation et les limites des technologies de communication unifiée entrant en jeu dans la conception de la plateforme. Ces deux phases ont été conduites dans une perspective de l’«action située» et suivant une méthodologie qualitative fondée sur des études par entretiens et par observations. Les résultats rendent compte des réalités des pratiques de travail à distance en situation de mobilité équipée, des limites des équipements et des tactiques construites par les acteurs pendant la «mise en pratique» de la technologie. Ces résultats révèlent aussi les normes, souvent tacites, et valeurs d’usages de ces nouvelles technologies et permettent d’appréhender leur conception au travers des recommandations managériales englobant leurs aspects technique, d’usage et de service. / This doctoral thesis in Management Sciences concerns the project WITE 2.0 dedicated to the analysis and the design of technical and organizational ICT device : an integrated platform for teleworking. This platform allows you to work "remotely" on a connected mode or not, from any device (PC, phone, tablet), on a "thin client" and in a work environment like « cloud computing ». Some questions have emerged related to the design of the platform : these questions concern the role of the information and communication technologies (ICT) in the progress of remote working. Our design of research is divided into two research’s actions : firstly, we wanted to know the diversity of remote working configurations and secondly, we wanted to understand how the appropriation’s codes and norms of the new technologies (used for the platform) take place. We followed an « situed action » perspective and a qualitative methodology based on semi-structured interviews and observations. In our results, we describe the remote working’s realities, the limitations of the technologies and the tactics built by the workers while they « enact » the technology remotly. We discovered some use’s norms, often in a tacit dimension, and use’s values of these new technologies. Finally we gave some managerial recommandations concerning the technical, use and service aspects.

Cette thèse porte sur plusieurs technologies de déchargement cellulaire pour les futurs réseaux sans fil avec l’amélioration envisagée sur la efficacité spatiale du spectre et l’efficacité énergétique. Notre recherche concerne deux directions principales, y compris la communication D2D underlaid dans les réseaux cellulaires et le caching proactif au bord de réseau.La première partie de cette thèse contient deux chapitres qui présentent nos résultats de recherche sur les réseaux cellulaire avec D2D underlaid. Notre recherche se focalise sur l’accès opportuniste distribué, dont la performance en termes du débit D2D est optimisé dans deux scénarios: 1) en supposant que l’utilisateur cellulaire avec un trafic saturé peut avoir une probabilité de couverture minimale; 2) en supposant que le trafic discontinu à l’utilisateur cellulaire, dont le délai moyen doit être maintenue au-dessous d’un certain seuil. La deuxième partie de cette thèse se focalise sur les méthodes de caching proactif au bord de réseau, y compris le caching aux petites cellules et aux appareils des utilisateurs. Tout d’abord, nous étudions le placement de contenu probabiliste dans différents types de réseaux et avec différents objectifs d’optimisation. Deuxièmement, pour le caching aux petites cellules, nous proposons un schéma coopérative parmi les petites stations de base, qui exploite le gain combiné du caching coopérative et les techniques de multipoint coordonnée. Les modèles de processus ponctuel nous permet de créer la connexion entre la diversité de transmission en couche PHY et la diversité de contenus stockés. / This thesis focuses on several emerging technologies towards future wireless networks with envisaged improvement on the area spectral efficiency and energy efficiency. The related research involves two major directions, including deviceto- device (D2D) communication underlaid cellular networks and proactive caching at network edge. The first part of this thesis starts with introducing D2D underlaid cellular network model and distributed access control methods for D2D users that reuse licensed cellular uplink spectrum. We aim at optimize the throughput of D2D network in the following two scenarios: 1) assuming always backlogged cellular users with coverage probability constraint, 2) assuming bursty packet arrivals at the cellular user, whose average delay must be kept below a certain threshold. The second part of this thesis focuses on proactive caching methods at network edge, including at small base stations (SBSs) and user devices. First, we study and compare the performance of probabilistic content placement in different types of wireless caching networks and with different optimization objectives. Second, we propose a cooperative caching and transmission strategy in a cluster-centric small cell networks (SCNs), which exploits the combined gain of cache-level cooperation and CoMP technique. Using spatial models from stochastic geometry, we build the connection between PHY transmission diversity and the content diversity in local caches.

Indiana University-Purdue University Indianapolis (IUPUI) / Biological cells are constantly subjected to mechanical forces such as tension, compression and shear. The importance of these forces in mediating cell signals, maintenance of lineages, promoting embryonic cell differentiation and tissue engineering is only now coming into focus. It has been shown that stretch stimulus can influence growth, differentiation, as well as tissue strength and integrity. Most stretch systems built to understand more of these phenomena suffer from shortcomings, as accurately replicating the in vivo environment is quite challenging. Many of the devices currently available are very expensive as well as limited to a single application. The objective of this thesis is to design, manufacture, test, and validate a novel uniaxial cyclic cell stretch device that overcomes most of the major limitations of existing systems, and to experimentally demostrate that uniaxial cyclic stretch causes a shift towards in vivo characteristics of smooth muscle cells. The stretch mechanism is driven by a single servo motor which makes its operation simple and straight forward. Coolworks Lite, a proprietary software of the servo motor supplier, is used to control the motor and LabVIEW is used to obtain feedback from the sensors. Validation for the stretch machine was done by evaluating the performance of the device against engineering requirements. Methods were suggested to improve shortcomings that were encountered. Also, the machine's unique design allows its extension to a biaxial stretch unit while keeping the same driver platform, a concept for which has been discussed and illustrated.