Dans un marché aéronautique en plein essor marqué par une croissance rapide du parc d’avions utilisées à travers le monde, l’optimisation de la maintenance devient une préoccupation pour les avionneurs. Il s’agit de maximiser la disponibilité des aéronefs tout en réduisant les couts directs d’exploitation sans compromis sur la sécurité des hommes et en respectant les contraintes environnementales. Une stratégie possible pour relever ce challenge est de renforcer la capacité à anticiper les défaillances afin de recourir à des actions préventives le plus juste possible sur les composants les plus critiques comme les roulements à billes. La mise en œuvre de processus de Prognostic Health Management (PHM) prend ainsi une part grandissante et le processus de pronostic est considéré comme l’un des principaux leviers d’action. Son déploiement requiert que le comportement du système étudié puisse être observés. Il peut ainsi bénéficier de l’apport des récentes avancées dans le domaine des microsystèmes autonomes en énergie permettant des mesures intelligentes et un transfert de données d’une manière distribuée, sans aucune aide externe. L’association de ses deux champs de recherche mène naturellement vers le roulement intelligent qui pourrait être la transition d’une maintenance programmée à une maintenance prédictive. Cependant les solutions de PHM autour du roulement et le roulement intelligent, ne restent pas moins le fruit de l’évolution des techniques et technologies de surveillance, de récupération d’énergie et de connectivité. C’est dans ce cadre que s’inscrit ce mémoire de thèse par Validation des Acquis de l’Expérience (VAE). Il s’articule en trois parties principales : motivations du VAE, état de l’art autour du roulement mécatronique et exemple de contributions autour de la récupération d’énergie et la communication sans fil à des fins de surveillance. / The aeronautic market is growing and the aircraft fleet size is becoming bigger. Maintenance optimization is a key focus for liner since objectives are to maximize the aircraft availability and to reduce the direct cost of ownership with no compromise on the flight security and safety with respect to environmental standards. To meet this challenge one possible strategy is to apply a PHM approach using the recent advance in the autonomous embedded microsystem field. This PhD work presents some work done around energy harvesting and wireless sensor to enable a smart bearing able to measure the usage and health data from the component in the purpose of predictive mainteance.

Essa dissertação de mestrado é dedicada ao estudo, desenvolvimento e caracterização da resposta dinâmica de transdutores de deformação mecânica e de temperatura baseados em grades de Bragg inscritas em fibras ópticas (FBG). Como não se encontram referências diretas na literatura da área sobre a caracterização da resposta dinâmica de sensores de temperatura e deformação a FBG, percebeu-se a importância de realizar um trabalho com ênfase nesse aspecto. O desenvolvimento de transdutores FBG de deformação e de temperatura com resposta dinâmica rápida é de grande importância, já que as grades de Bragg são afetadas, de maneira intrínseca, simultaneamente pelas duas grandezas e que existe um amplo leque de aplicações em que uma delas, ou ambas, variam rapidamente. Nesses casos, diferenças em termos de tempos de resposta entre os sensores utilizados para medição de deformação e os usados para compensação de temperatura podem acarretar em erros significativos nas medidas, o que pode até inviabilizar o uso dos sensores a grades de Bragg em tais aplicações. Este trabalho apresenta um compêndio da teoria da tecnologia das FBG para aplicação em sensores ópticos de deformação e de temperatura. Buscando contribuir para o domínio das técnicas de fabricação de sensores a FBG no Brasil, também são apresentados os resultados experimentais da utilização de grades de Bragg inscritas em fibras ópticas fabricadas no laboratório da Subdivisão de Sensores (EFO-S), da Divisão de Fotônica do Instituto de Estudos Avançados (IEAv) do Comando-Geral de Tecnologia Aeroespacial (CTA), como elementos sensores em ensaios de deformação e de temperatura. Os resultados de caracterizações, tanto de FBG produzidas no IEAv quanto de sensores de deformação e de temperatura comerciais das empresas Micron Optics e Fiber Sensing, foram obtidos por meio de três interrogadores diferentes e são comparados e apresentados neste trabalho. Em uma análise realizada dos resultados apresentados de sensores a FBG, utilizados para medição de temperatura e de deformação mecânica em alguns arranjos experimentais, foram observados comportamentos dinâmicos não lineares que apresentam-se como um obstáculos a serem vencidos para a viabilização da aplicação desta técnica à medição desses parâmetros quando os mesmos são rapidamente variáveis. / This dissertation is devoted to the study, development and characterization of the dynamic response of mechanical strain and temperature transducers based on Bragg gratings inscribed in optical fibers (FBG). Since there are no direct references in the literature on the characterization of the dynamic response of FBG based temperature and strain sensors, it was realized the importance of conducting a study with emphasis on this aspect. The development of FBG strain and temperature transducers with fast dynamic response is of great importance, since the Bragg gratings are intrinsically and simultaneously affected by the two quantities and there is a wide range of applications in which one or both quantities vary rapidly. In such cases, differences in response times between the sensors used for measurement of strain and used for temperature compensation can result in significant errors, which may even preclude the use of FBG sensors in such applications. This work presents a compendium of the theory related to FBG technology for application in optical strain and temperature sensors. Seeking to master the techniques of manufacture of the FBG sensors in Brazil, experimental results from the use of FBG manufactured in the laboratory of Sensors Subdivision (EFO-S), of Photonics Division of Institute of Advanced Studies (IEAv) of General Command for Aerospace Technology (CTA) as sensor elements in strain and temperature trials are also presented. The results of both characterizations, of FBG produced in IEAv and strain and temperature commercial sensors, produced by Micron Optics and Fiber Sensing manufacturers, were obtained from three different interrogators and are compared and presented in this paper. In an analysis of the results of FBG sensors used for measuring temperature and mechanical deformation in some experimental arrangements, nonlinear dynamic behaviors were observed. Such behaviors present themselves as an obstacle to be overcome to achieve the feasibility of applying this technique to measurement of these parameters when they are rapidly changing.

This thesis deals with creating hardware and software equipment of intelligent beehive for data collection purpose. Measurement characteristics are temperature, humidity, weight of beehive and audio record of bees. They are measured by available IoT technology. They are simple single-chip component with a clear focus. This thesis also include creation of software for measurements this characteristics and communications with server. The software featured of the remote server are also documented. This software analyze incoming measurement and also provides their displays. Software in this thesis is developed in language Python.

Using bandgap engineering, silicon-germanium (SiGe) BiCMOS technology effectively combines III-V transistor performance with the cost and integration advantages associated with CMOS manufacturing. The suitability of SiGe technology for cryogenic and radiation-intense environments is well known, yet SiGe has been generally overlooked for applications involving extreme high temperature operation. This work is an investigation into the potential capabilities of SiGe technology for operation up to 300°C, including the development of packaging and testing procedures to enable the necessary measurements. At the device level, SiGe heterojunction bipolar transistors (HBTs), field-effect transistors (FETs), and resistors are verified to maintain acceptable functionality across the temperature range, laying the foundation for high temperature circuit design. This work also includes the characterization of existing bandgap references circuits, redesign for high temperature operation, validation, and further optimization recommendations. In addition, the performance of temperature sensor, operational amplifier, and output buffer circuits under extreme high temperature conditions is presented. To the author's knowledge, this work represents the first demonstration of functional circuits from a SiGe technology platform in ambient temperatures up to 300°C; furthermore, the optimized bandgap reference presented in this work is believed to show the best performance recorded across a 500°C range in a bulk-silicon technology platform.

The objective of this work is to enhance and advance sensing technologies with the design and development of novel radio frequency (RF) sensors based on far-field and near-field principles of the electromagnetic (EM) resonances. In the first part of this thesis, original design and development of a passive RF temperature sensor, a passive RF strain sensor, and a passive RF pressure sensor are presented. The RF temperature sensor is presented in Chapter 3. It is based on split ring resonators loaded with bimorph cantilevers. Its operating principles and equivalent circuits are discussed in Chapter 4, where the design concept is illustrated to be robust and highly adaptable to different sensing ranges, environments, and applicable to other type of sensing beyond temperatures. The passive RF strain sensor, based on a patch antenna loaded with a cantilever-integrated open loop, is presented in Chapter 5, where it is demonstrated to have the highest strain sensitivity in the same remote and passive class of sensors in the state-of-the-art. Chapter 6 describes the passive RF pressure sensor, which is based on a dual-band stacked-patch antenna that allows both identification and sensing to be embedded in its unique dual resonant responses. In the second part of this thesis, an original and first-of-its-kind RF transducer is presented that enables non-touch sensing of human fingers within 3 cm of proximity (based on one unit sensor cell). The RF transducer is based on a slotted microstrip patch coupled to a half-wavelength parallel-coupled microstrip filter operating in the frequency range of 6 – 8 GHz. The sensing mechanism is based on the EM near-field coupling between the resonator and the human finger. Fundamentally different from the electric field capacitive sensing, this new method of sensing, the first of its kind, based on near-field interference that produces a myriad of nonlinearities in the sensing response, can introduce new capabilities for the interface of electronic displays (the detection is based on pattern recognition). What set this sensor and its platform apart from previous proximity sensors and microwave sensing platforms is the low profile planar structure of the system, and its compatibility with mobile applications. The thesis provides both breadth and depth in the proposed design and development and thus presenting a complete research in its contributions to RF sensing.

The temperature sensor design discussed in this thesis, is meant mainly to monitor temperature at power outlets. Current variations in power cords have a direct impact on the surrounding temperature. Sensing these variations ,enables us to take necessary measures to prevent any hazards due to temperature rise. Thus, for this application we require a sensor with a moderate temperature error (_10C) over a sensing range of -200C to 1500C. Low power consumption and simple digitizing scheme alleviate measurement errors due to self heating effects of the sensor. A current starved inverter based ring oscillator was chosen for the sensor design in 130nm technology. The inverter delay variation with temperature is used for sensing. Linearity and process invariancy of these characteristics are fundamental to the sensor design. We observed through simulations, and confirmed by mathematical analysis, that the sensing characteristics are governed by bias current dependence on temperature. Control voltage for the bias circuitry of the oscillator determines current through the inverter stages. Hence, for linear sensing characteristics, a control voltage(Vc) just above the maximum threshold voltage of bias transistor is used. This enables generation of PTAT saturation current for current starved inverters, due to dominance of threshold voltage decrease with temperature over mobility decrease. I.Another limitation, process dependency of the sensing characteristics, was overcome through the proposed calibration based compensation technique. A changing Vc proportional to threshold voltage variation with process, process independent bias current and current temperature characteristics were obtained. This compensated for the process variation effects on frequency. Thus, a variable Vc was generated using a reference with low temperature sensitivity of 17.6_V=0C, and resistive divider combinations for various processes. Incorporating this compensation technique we achieved good linearity in sensor characteristics and a maximum temperature error of± 1.60C over the sensing range. The sensor consumes a low power of 0.29mW and also occupies minimal area.

This thesis deals with problems related to heating of hot service water. It focuses on solar water heating, describes individual types of solar panels and summarizes the existing information about solar water heating. It demonstrates actual problems of solar system solution on a specific example of a two-generation family house, where it analyses possibilities of diagnostics and control of such system. It also deals with suggestions of possible expansion of the current solar system.

This paper deals with the hardware and software design of the data acquisition distributed system with large amount of connected sensors. The intended application of this work is measuring some physical quantities in the building constructions. The designed system is hierarchically divided into the three levels. On the highest level there is a single-board computer Raspberry Pi which is used as a master on RS-485 bus. There can be up to 32 slave devices on the bus while each of them collects data from the sensors connected to 4-channel I2C bus. At the same time the Raspberry Pi is used as a web server, providing the user interface of the system.

<div>A microheater and resistance temperature detector (RTD) are designed and fabricated for various applications. First, a hierarchical manifold microchannel heatsink with an integrated microheater and RTDs is demonstrated. Microfluidic cooling within the embedded heat sink improves heat dissipation, with two-phase operation offering the potential for dissipation of very high heat fluxes while maintaining moderate chip temperatures. To enable multi-chip stacking and other heterogeneous packaging approaches, it is important to densely integrate all fluid flow paths into the device. Therefore, the details of heatsink layouts and fabrication processes are introduced. Characterization of two-phase cooling as well as reliability of the microheater/RTDs are discussed. In addition, another application of microheater for mining particle detection using interdigitated capacitive sensor. While current personal monitoring devices are optimized for monitoring microscale particles, a higher resolution technique is required to detect sub-micron and nanoscale particulate matters (PM) due to smaller volume and mass of the particles. The detection capability of the capacitive sensor for sub-micron and nanoparticles are presented, and an incorporated microheater improved stable capacitive sensor reading under air flow and various humidity. </div><div>This paper also introduces the characterization of nanomaterials such as metallic nanowires (NWs) and single layer graphene. First, the copper nanowire (CuNW)/graphene hybrid networks for transparent conductors (TC) is investigated. Though indium tin oxide (ITO) has been widely used, demands for the next generation of TC is increasing due to a limited supply of indium. Thus, the optical and electrical properties of CuNW/graphene hybrid network are compared with other transparent conductive materials including ITO. Secondly, silver nanowire (AgNW) growth technique using electrodeposition is introduced. A vertically aligned branched AgNW arrays is made using a porous anodic alumina template and the optical properties of the structure are discussed.</div><div><br></div>

We need to employ modern-day technologies in our daily lives to make our life easier. In this thesis, we analyze the user’s oral hygiene habits and core body temperature to help people to track the state of their health. We designed a system in which the data are directly extracted from the mouth, then stored and presented in the application. By means of the system, the people can keep track oftheir core temperature without any extra function apart from their daily chores.The system can also help to keep track of the health of people with symptoms ofdementia and Alzheimer. We used an LM35 temperature sensor to measure temperature. The sensor is mounted on a powered toothbrush head. When the user starts to brush, the sensor records the temperature data for seven times in two minutes of an average brush time and sends it to the mobile application using WiFi. We used a NodeMCUboard, ThingSpeak server and MIT inventor app to transfer the data and designthe mobile application.