Tesis sobre el tema "Capteurs flexibles"
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Le, Scornec Julien. "Micro-générateurs aéroélectriques flexibles pour l’auto-alimentation de capteurs communicants". Thesis, Nantes, 2020. http://www.theses.fr/2020NANT4039.
Texto completoThe advent of the Internet of Things has rendered the ambient energy harvesting a major issue for powering communicating microsystems. In this context, this work focuses on the development of a flexible piezoelectric micro-generator able to convert the mechanical energy from low airflows. The objective is to develop autonomous microsystems, or at least to extend their lifespan with energy harvesting. To harvest ambient energy, the flexible micro-generators are made of 3 μm-thick lead zirconate titanate (PZT) thin films encapsulated between polyethylene terephthalate (PET) films. The manufacturing process of the micro-generators has been optimized in order to increase their energy efficiency. Both the optimization of the electrode structure and the geometry of the generator made the maximum harvested power increase by a factor of 625. In this work, to characterize the energy harvesting, the micro-generators were excited with different systems (shaker, traction/compression system and wind tunnel). Thus, wind tunnel tests have shown that it was possible to harvest a power of 38 μW at 10 Hz when the generator was subjected to a low airflow (6 m/s). This generator allowed to power a communicating temperature sensor during several measurement/data transmission cycles
Takpara, Rafatou. "Développement de capteurs piézoélectriques interdigités flexibles pour la caractérisation ultrasonore des revêtements". Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0041/document.
Texto completoThis work deals with the realization of interdigital sensors (IDT for InterDigital Transducer) on piezoelectric substrates. There is a dual challenge since firstly, the aim is to have efficient sensors to generate surface acoustic waves (SAW) in order to characterize the quality of the coatings and structure surfaces. The second objective of this study is to make these IDT sensors flexible so as to adapt to different geometries of structures and to be able to put up with the deformations of structures in use. Typically, piezoelectric materials are rigid and the flexible nature of the materials is often in opposition to the piezoelectric performance of the latter. We developed materials that meet these two requirements: piezoelectricity and flexibility. Finally, we gave greater importance to relatively cheap technologies to develop these sensors because this allows then to consider continuous monitoring (structural health monitoring) by incorporating these sensors permanently on the structures to be tested
Villafuerte, Diaz José Guillermo. "Nanofils de ZnO résistifs synthétisés par dépôt en bain chimique pour capteurs piézoélectriques flexibles". Thesis, Université Grenoble Alpes, 2022. http://www.theses.fr/2022GRALI056.
Texto completoHighly resistive ZnO NWs are intended for their application as pressure sensors in flexible substrates. To achieve this, it was important to develop the important role of hydrogen- and nitrogen-related defects in ZnO NWs grown by CBD, as it has been extensively studied in this thesis. Chapter 1 details the state-of-the-art of the present thesis and Chapter 2 details the experimental procedures used to develop the different studies of this thesis. In Chapter 3, the metal-like electrical conduction of spontaneously grown ZnO NWs was attributed to a high density of free charge carriers due to hydrogen-related defects (i.e., HBC and VZn-3H acting as shallow donors). Then, Chapter 4 demonstrates the capacity to engineer the ZnO NWs by thermal annealing under an oxygen atmosphere, showing that the density of hydrogen-related defects would decrease at ~300 °C, and the thermal activation of VZn-NO-H (acting as deep acceptor) at ~450 °C would promote an important compensation. Furthermore, the intentional incorporation of Sb dopant atoms in the ZnO NWs bring a novel approach by performing the growths in the low- and high-pH regions, as performed in Chapter 5. Hence, Chapter 6 elucidates the complex modulation between the hydrogen-, nitrogen- and antimony-related defects at the different growth conditions and the different annealing conditions. Particularly, the novel two-step annealing at 300 °C for 4 h and a consecutive 1 h at 450 °C will illustrate the possibility to exo diffuse the hydrogen-donors and thermally activate the VZn-NO-H and Sb-related defects. Finally, Chapter 7 shows the incorporation of these highly resistive ZnO NWs as flexible piezoelectric sensors
DE, PIERI EDSON ROBERTO. "Modelisation et commande de structures flexibles : reduction du modele, placement des capteurs et commande robuste". Paris 6, 1991. http://www.theses.fr/1991PA066611.
Texto completoSelmene, ep Ben Hassine Nissem. "Etude et développement de capteurs tactiles flexibles à détection harmonique vers la fonctionnalisation sensitive des surfaces". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM028/document.
Texto completoThe advent of sensitive interfaces is promising prospects to the human-machine interaction. We propose a new concept of sensitive flexible surface. Its aim is to study the interaction between electrical signal and resistive and dielectric environment of the support in order to realize an acquisition system providing machine readable information.The technological base is a waveguide on flexible substrate on which the touch creates a reflection at the input port. We have developed a location method as an alternative to the time domain reflectometry (TDR). It is named Harmonic Detection and Location (HDL) and it allows using a narrow band, around 100 MHz, low complexity acquisition system. The concept has been approved using measures on flexible and rigid sensitive surfaces connected to a vector network analyzer (VNA) used as reference. A compact acquisition system based on a Wheatstone bridge associated to a phase detector has been developed. For this purpose, errors characterization and identification work has been done. Electromagnetic interactions between the finger and the waveguide, waveguide imperfections, substrate nature and acquisition system errors’ impact have been studied. This knowledge has provided the possibility to co-develop the hardware and the detection algorithm to demonstrate a location accuracy of 2cm. Fundamental principles of this work provide the possibility of realizing large surface interfaces, with simple connection and conformable, for 3D sensitive objects
Jemai, Brahim. "Contrôle actif de structures flexibles à l'aide de matériaux piezo-électriques : Applications". Ecully, Ecole centrale de Lyon, 1999. http://www.theses.fr/1999ECDL0023.
Texto completoA given mechanical system is dependant on its environment at the time of its operation. The excitation sources and the connections with its environment makes the system produces adverse effects such as the noises and the vibrations. Such a system behaves according to positive and total natural laws'. Active control aims to act on these laws and makes it possible to confer on the system a behavior with better dynamic performances. With this intention one integrates into the basic structure a set of sensors to measure its vibratory state and a set of actuators to apply a command generated by a controller in order to bring the structure in a state fixed before. In this work, it is a question of studying the active control of light and flexible structures using peizoelectric materials. These structures are abundantly used in aeronautical construction. A fundamental problem arises during the control of such structures : it is the phenomenon of the modal contamination (effet Spillower) which occurs as instabilities
Degryse, Emmanuel. "Etude d'une nouvelle approche pour la conception de capteurs et d'actionneurs pour le contrôle des systèmes flexibles". Compiègne, 2001. http://www.theses.fr/2001COMP1363.
Texto completoAmestoy, Antoine. "Synthèse de nanohélices hybrides par auto-assemblage de type "bottom up" pour la fabrication de capteurs de déformation flexibles". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0041.
Texto completoFlexible and biocompatible strain sensors based on nanoparticle (NPs) assemblies show great potential for various future applications, such as electronic skin, flexible touch screens, and robotics. The high sensitivity of such strain sensing devices is due to the exponential dependence of the tunnel resistance on the distance between adjacent NPs, which is altered by the strain. However, the sensitivity, reproducibility and stability of these sensors are affected by variations in thickness, morphology and density of the films during manufacture or during their application. The objective of this work is to develop strain sensors based on assemblies of silica nanohelices covered with conductive metallic NPs or semiconducting metal oxide NPs to overcome these critical aspects. In the first part, gold NPs are synthesized and functionalized with different compositions of insulating ligands and are further grafted on the surface of the nanohelices with a covalent bond. In the second part, transparent semiconducting NPs of antimony-doped tin oxide are synthesized, functionalized and assembled on the surface of nanohelices by electrostatic or covalent interactions. Finally, the various assemblies obtained are deposited by dielectrophoresis between interdigitated electrodes on a flexible substrate. The flexibility, sensitivity and stability properties of the sensors are then characterized by electromechanical measurements coupled with scanning electron microscopy observations
Ganesan, Sivaramakrishnan. "Utilisation de la résonance plasmonique de surface pour la réalisation de capteurs appliqués au domaine phytosanitaire". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I059.
Texto completoThe overall goal of this study was to develop a portable biological detection system with high sensitivity, accuracy and repeatability to be used in either the phytosanitary or the medical domain. This system is based on the Surface Plasmon Resonance (SPR) physical principle. Such a use of this principle is already achieved but leads to laboratory equipment. The goal here is to democratize its use up to an on field or point of care measurement system. In this context and within the frame of the BIOSENS INTEREG FWVL project, I worked more particularly on several developments around the sensor. From all the existing biosensor technologies, surface plasmon resonance (SPR) sensing technology has received continuous attention due to its advantages of a high-sensitivity, label-free and fast response time. Although the SPR sensing technique being legend in the sensor community, currently the temperature of the sample needs to be carefully maintained and controlled because SPR signal varies with temperature and any change in SPR signal can be interpreted as a biological interaction. This gives a huge challenge in the portable application that is targeted since embedding of a temperature controlled chamber size and energy consuming. A SPR sensor design including 4 SPR channels has been made and the temperature is controlled in real time by using Joule effect. Temperature behavior has been modelled under COMSOL and we experimentally demonstrated that the temperature modulation of SPR channel by Joule effect does not affect the detection scheme. Water was heated by injecting current through the plasmonic layer and the refractive index change of water due to temperature was measured and compared with the theory. We also demonstrated that the temperature of each of the 4 channels can be controlled independently without any thermal crosstalk. In order achieving a more precise monitoring of sample temperature, a temperature sensor was also fabricated on top of the plasmonic layer, allowing the real temperature at the sensor surface to be monitored in real time. This temperature control can so be used either to maintain the temperature of biologic samples or to identify the effect of temperature on biomolecular interactions. On addressing the cost of the sensing tool, a flexible and cheap SPR sensor made on tape has been fabricated and tested. Air and water plasmonic responses were measured using such a "tape sensor". A PDMS prism has already been investigated and combined to the tape sensor making then a very cheap sensing platform
Delabre, Benjamin. "Développement de capteurs flexibles à courants de Foucault : applications à la caractérisation des propriétés électromagnétiques des matériaux et à la détection de défauts par imagerie statique". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS415/document.
Texto completoThe work of this thesis focuses on the development and the optimization of probes for non-destructive testing (NDT) by Eddy Currents (EC). The manuscript presents several achievements of flexible EC probes engraved on Kapton film. The first part describes the evaluation of the electromagnetic parameters (electrical conductivity σ and magnetic permeability µ) of materials typically encountered in NDT by EC. Conventional methods to estimate σ and μ have been investigated and implemented: it is the four-point probe and the permeameter. However, these methods present practical difficulties relating to the surface condition (paint, corrosion,…) and the sample geometry. Two probes have therefore been designed: the first is composed of a transmitting and a receiving coil in order to evaluate the conductivity of purely conductive materials, and the second is composed of a transmitter coil and a GMR for evaluate the magnetic permeability. Design patterns and experimental results are presented in the manuscript. The second part describes the development of a flexible static EC imager. The imager is a multielement probe composed of 576 receivers arranged in a matrix allowing to inspect the surface of a structure under test without moving the probe relative to the sample surface. The inspection by the static imager provides a pixelated image of the surface under the probe. The imager has been optimized to detect a surface defect of at least 1 mm long of given orientation regardless of its location relative to the receiver coils. The design of the probe and its experimental evaluation are given in the manuscript
Abriat, Patrick. "Conception et réalisation d'un système multi-agent de robotique permettant de récupérer les erreurs dans les cellules flexibles". Compiègne, 1991. http://www.theses.fr/1991COMPD411.
Texto completoLaaraibi, Abdo-rahmane Anas. "Development of an autonomous system based on piezoresistive sensors for quantitative sports movement". Electronic Thesis or Diss., Université de Rennes (2023-....), 2024. http://www.theses.fr/2024URENE001.
Texto completoHuman motion analysis plays a vital role in numerous fields, enabling, for instance, the understanding of the nuances of physical performance or biomechanics. The data and information derived from this motion analysis can enhance performance, prevent injuries, or optimize rehabilitation. Various systems exist, such as video, but their implementation and data processing pose limitations. One solution is to develop integrated wearable systems offering discreet and continuous activity tracking. One challenge lies in the materials and instrumentation domain, where the objective is to develop wearable and autonomous systems that meet the requisite specifications. This thesis work focuses on the design of piezoresistive transducers for the development of energy-autonomous systems, such as an insole for estimating plantar force and a garment for determining joint angles. A viscoelastic model of the piezoresistive transducer has been established, which enables the estimation of plantar force by inversion. Comparative experiments have been conducted with commercial systems, including a force platform
Lonjaret, Thomas. "Micro-fabrication of wearable and high-performing cutaneous devices based on organic materials for human electrophysiological recordings". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM021/document.
Texto completoElectrophysiology is the study of electrical and electrochemical signals generated by specific cells or whole organs. It gives doctors the opportunity to track the physiological behavior of a single neuron, as well as the integral brain. The recording of these activities is essential to diagnose and better understand diseases like cardiac arrhythmias, epilepsy, muscular degeneration and many more. In this thesis, we study different types of cutaneous electrodes based on organic materials, from conception to pre-clinical evaluation. Our approach is based on the usage of PEDOT:PSS conducting polymer and ionic gels in order to reduce impedance at the skin-electrode interface. Moreover, the substrate of our electrodes is made with different materials such as thin and conformable plastics and textiles. Our devices are then flexible, motion resistant and can be integrating into clothes. We developed new fabrication processes, considering the different substrates and organic materials specifics. The electrodes were characterized and then tested on human volunteers to show their excellent performance in comparison to standard medical electrodes. The evaluation of noise reduction capabilities and possibilities to perform long-term recordings were established on signals coming from muscles, heart and brain. Furthermore, we present a hundred micrometer-small “active” electrode, based on the organic electrochemical transistor. It enables in situ amplification and filtering of recorded signals. The wearable organic electrodes developed in this work are of great industrial and clinic interest. Future work will aim to integrate these technologies into state-of-the-art medical devices
Nohava, Lena. "Concepts for Wearable Technology in MR : Lightweight Flexible Radio Frequency Coils and Optical Wireless Communication Flexible multi-turn multi-gap coaxial RF coils: design concept and implementation for Magnetic Resonance Imaging at 3 and 7 Tesla Perspectives in Wireless Radio Frequency Coil Development for Magnetic Resonance Imaging". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST069.
Texto completoThis PhD thesis work was conducted at the BioMaps laboratory at the Université Paris-Saclay and the Center for Medical Physics and Biomedical Engineering (CMPBME) at the Medical University of Vienna.To improve diagnostic value in MRI, shorter acquisitions, more efficient patient handling and improved image quality are needed. Wearable technology with optimized hardware reduces weight, increases flexibility, and could be wireless, thereby improving sensitivity, comfort, safety, and usability.In this work, flexible self-resonant coaxial transmission line resonators were investigated. Coaxial coils with multiple turns and gaps enable size optimization depending on the target application. The design was first studied in silico. Numerous prototypes were constructed and their performance was tested on the bench and in 3 and 7 T MRI. Coaxial coils were shown to be robust against bending, have no SAR penalty and improve SNR and transmit efficiency when form-fitted.A review of wireless MR, associated hardware developments and data transmission technology is given.An optical wireless communication module for sensor data transmission was demonstrated experimentally.Wearable coaxial coils offer an attractive alternative to standard coils due to low weight and flexibility. With wireless motion sensors diagnostic value in e.g. breast, knee, or cardiac MRI could be increased
Acuautla, Meneses Monica Isela. "Development of ozone and ammonia gas sensors on flexible substrate". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4337/document.
Texto completoNowadays the emerging of new applications in the micro and nanotechnology field required to reduce fabrication costand to improve electronic devices with properties such as flexibility, portability, lightweight, and low cost. Traditional methods involve expensive and long production steps, and chemical vapor deposition. The purpose of this work is to present the conception and characterization of flexible ammonia and ozone sensors fabricated by photolithography and laser ablation processes. The flexible platform is composed of Kapton substrate with interdigitated Ti/Pt electrodes for gas detection and a micro-heater device. The circuit patterns were realized by photolithography and laser ablation. Photolithography is a well-known and reliable patterning process used on rigid substrate. The application of laser ablation process not only reduces fabrication time, but also represents an excellent viable alternative instead of chemical processes. ZnO thin films deposited by drop coating have been used as sensitive materials due to their excellent properties in the gas detection. The gas sensing condition and the performances of the devices are investigated for ozone and ammonia at different gas concentrations and different thin film thicknesses. In order to test a deposit methodology used in large scale industrial production, an ultrasonic spray deposition was done. The sensor provides a wide range of detection from 5 ppb to 500 ppb for ozone and from 5 ppm to 100 ppm for ammonia. Their best sensibilities were obtained at 200°C for ozone and 300 °C for ammoniac with good repeatability, stability and fast response/recovery time
Back, Antoine. "Conception et intégration d'un convertisseur analogique-paramètres flexible pour les capteurs intelligents". Electronic Thesis or Diss., Institut polytechnique de Paris, 2022. http://www.theses.fr/2022IPPAT020.
Texto completoThe Internet of Things (IoT) is currently experiencing huge developments. IoT includes lots of different devices such as Wireless Sensors Networks (WSN) or wearable electronics that rely on wireless communications. These networks need to understand the context in which they are used. This mean that the system must know what is happening around it, i.e. sense the environment, and understands the needs of the user. This requires always-on sensing on many sensors while being small, cheap, reliable and having a lifetime of several years. Analog-to-Feature (A2F) conversion is a new acquisition method that was thought for IoT devices. The converter aims at extracting useful features directly on the analog signal. By carefully choosing a set of features, it is possible to acquire only the relevant information for a given task. The proposed converter is based on the Non-Uniform Wavelet Sampling (NUWS) architecture. The architecture mixes the analog signal with tunable wavelets prior to integration and digital conversion. The aim of the thesis is to propose a method to design a generic A2F converter based on the NUWS. It includes the definition of the wavelet parameters in order to acquire a broad range of low frequency signals (ECG, EMG, EEG, speech …). This step requires the use of feature selection algorithms and machine learning algorithms for selecting the best set of wavelets for a given application and should be used to define the specifications for the converter. The feature selection step must be aware of physical implementation constraints to optimize energy consumption as much as possible. A feature selection algorithm is proposed to choose wavelets for a given application, in order to maximize classification accuracy while decreasing power consumption, through a power model designed in CMOS 0.18μm
Belaizi, Yassin. "Etude et conception d'un capteur-RFID passif en bande UHF : application à l'agroalimentaire". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS061/document.
Texto completoRadio frequency identification (RFID) technology is available today in thousands of applications. Among them we can mention the logistics management applications pallets / cardboard in industrial warehouses (RFID UHF) and the identification of subscribers in urban transport networks (RFID HF). In recent years, scientific contributions around the radio frequency identification (RFID) technologies with a sensor coupling are increasingly visible. The growing interest in this type of development rely heavily on a mass use of inexpensive sensors that can be integrated on each object.It is calledconnected objects or Internet of Things (IoT). In this thesis, we focus on the study and development of a passive RFID sensor operating in UHF band. This technological orientation is dictated by the targeted application, the food industry, which requires the lowest possible manufacturing costs and a reading distance greater than one meter. For the sensitive element, we use a biopolymer, specifically wheat gluten whose dielectric properties as a function of relative humidity have been studied previously. We are committed to dealing with all the issues related to the communication between a reader and a passive RFID sensor, the ultimate objective of this thesis being to get a sensor information using a conventional RFID reader complying with the standards and the radio directives imposed in different regions of the world. To validate this study, we are implementing RFID sensors to create a smart packaging demonstrator for monitoring the quality of food
Vallérian, Mathieu. "Une infrastructure flexible de collecte et de traitement de données d’un réseau de capteurs urbain mutualisé". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI058/document.
Texto completoIn this thesis, a receiver architecture for a gateway in a urban sensors network was designed. To embed the multiple protocols coexisting in this environment, the best approach seems to use a reconfigurable architecture, following the scheme of the Software-Defined Radio (SDR). All the received signals should be digitized at once by the Analog-to-Digital Converter (ADC) in order to sustain the reconfigurability of the architecture: then all the signal processing will be able to be digitally performed. The main complication comes from the heterogeneity of the propagation conditions: from the urban environment and from the diversity of the covered applications, the signals can be received on the gateway with widely varying powers. Then the gateway must be able to deal with the high dynamic range of these signals. This constraint applies strongly on the ADC whose resolution usually depends on the reachable digitized frequency band. A first study is led to evaluate the required ADC resolution to cope with the dynamic range. For this the dynamic range of the signals is first evaluated, then the required resolution to digitize the signals is found theoretically and with simulations. For a 100~dB power ratio between strong and weak signals, we showed that the ADC resolution needed 21 bits which is far too high to be reached with existing ADCs. Two different approaches are explored to reduce analogically the signals' dynamic range. The first one uses the companding technique, this technique being commonly used in analog dynamic range reduction in practice (\emph{e.g.} in audio signals acquisition), its relevance in multiple signal digitization is studied. Three existing compression laws are explored and two implementations are proposed for the most efficient of them. The feasibility of these implementations is also discussed. In the second approach we propose to use a two-antennas receiver architecture to decrease the dynamic range. In this architecture two digitization paths are employed: the first one digitizes only the strongest signal on the band. Using the information we get on this signal we reconfigure the second branch of the architecture in order to attenuate the strong signal. The dynamic range being reduced, the signals can be digitized with an ADC with a lower resolution. We show in this work that the ADC resolution can de decreased from 21 to 16 bits using this receiver architecture. Finally, the promising two-antennas architecture is tested in experimentation to demonstrate its efficiency with dynamic signals (\emph{i.e.} with appearing and disappearing signals)
Chauvin, Adrien. "Couches minces et nanofils métalliques nanoporeux : de la synthèse aux applications comme capteurs à effet SERS ou conducteur flexible transparent". Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4042/document.
Texto completoThe main objective of this thesis is to study the dealloying process of metal alloy thin films and nanowires deposited by magnetron sputtering which is a versatile process allowing growing alloys with a large panel of morphologies. We explore the influence of the deposition parameters on the morphology of the alloy films and nanowires and how in turn they impact the dealloying process. We further demonstrate that it is possible to create nanoporous lamellar films by selective etching in nitric acid of multilayered thin films consisting of stacks of gold/copper nanolayers. Furthermore, we show how by combining the deposition of gold-copper alloy by magnetron sputtering on “template” substrate and electrochemical dealloying one can create planar arrays of nanoporous gold nanowires with a tunable morphology. In term of application, the various nanoporous structures developed so far in this work are then used for the development of SERS-based sensors for the detection of small molecules. We obtain a detection limit at picomolar level (between 10-12 and 10-14 mol.L-1) with bipyridine as probe molecule using the nanoporous lamellar films. Moreover, we demonstrate a novel process based on applying dealloying using acidic vapors allowing fabricating highly flexible and transparent gold nanomesh electrodes suitable for flexible electronics. The obtained gold nanomesh electrodes may exhibit a resistivity as low as 44 Ω/□ and a transmittance of 79 % with a slight increase in resistance of less than 8 % after 10 000 bending cycles at 1 %
Dankoco, Mariam Dème. "Conception et réalisation de capteurs (température et pouls) imprimés sur support souple". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4318.
Texto completoThis thesis is a part of the collaborative research project VEADISTA (Remote monitoring of vital parameters and smart alerts) based on the conception of an ergonomic technology at low-cost.The objective of this thesis is to design and to realize printed temperature and pressure sensors on flexible support for biomedical applications. Subsequent to this, these sensors must be suitable to an integration on a passive transponder remotely powered, conformable to fit the patient's arm, low cost and allowing a technological transfer towards industry.Prototype tests were realized in order to identify the most promising topology and active layer to achieve printed temperature sensors on flexible support. At the end of this preliminary study, a RTD based on a silver ink was performed by inkjet on a flexible substrate (Kapton). The characterization of these sensors allowed to assess their sensitivity and to attest to their good linearity.The preliminary tests on commercial sensors were then made to demonstrate that it was possible to detect the heart rate with a pressure sensor. Following this study, pressure sensors were manufactured on flexible support using inkjet technology. These sensors were electrically characterized under controlled mechanical constraint. To achieve these results, many technological developments were realized around the inkjet printing technique. The mastery of the ink – inkjet head – substrate interaction is indeed essential for obtaining good printed quality and functional sensors
Dankoco, Mariam Dème. "Conception et réalisation de capteurs (température et pouls) imprimés sur support souple". Electronic Thesis or Diss., Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4318.
Texto completoThis thesis is a part of the collaborative research project VEADISTA (Remote monitoring of vital parameters and smart alerts) based on the conception of an ergonomic technology at low-cost.The objective of this thesis is to design and to realize printed temperature and pressure sensors on flexible support for biomedical applications. Subsequent to this, these sensors must be suitable to an integration on a passive transponder remotely powered, conformable to fit the patient's arm, low cost and allowing a technological transfer towards industry.Prototype tests were realized in order to identify the most promising topology and active layer to achieve printed temperature sensors on flexible support. At the end of this preliminary study, a RTD based on a silver ink was performed by inkjet on a flexible substrate (Kapton). The characterization of these sensors allowed to assess their sensitivity and to attest to their good linearity.The preliminary tests on commercial sensors were then made to demonstrate that it was possible to detect the heart rate with a pressure sensor. Following this study, pressure sensors were manufactured on flexible support using inkjet technology. These sensors were electrically characterized under controlled mechanical constraint. To achieve these results, many technological developments were realized around the inkjet printing technique. The mastery of the ink – inkjet head – substrate interaction is indeed essential for obtaining good printed quality and functional sensors
Arora, Neha. "Contribution to the concept of micro factory : design of a flexible electromagnetic conveyor system". Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2347.
Texto completoThe aim of the thesis is to provide a flexible conveyor system for moving micro-objects. The system may need to be integrated into a micro-factory which requires high reconfigurability and low power consumption. These two criteria have been considered in the design of the conveyor system. The conveyor is based on a planar electromagnetic actuator developed in the Laboratoire Roberval of the UTC, and on smart surface composed of 5 x 5 unit cells; each ceii moves th movable part in the two directions of the plane. An analytical model of the actuator has been developed in order to calculate the electromagnetic forces and the displacement of the mobile part. This modei has been used during the design phase of the conveying system. An experimental prototype is then manufactured and tested which has validated the proposed principle of operation. Experimental tests have shown the ability to perform wide area displacement in both directions of the plane. Numerous experimental tests (control in open loop and closed loop performance characterization as straightness of movement, position repeatability, coupled- decoupled analysis...) have been done to qualify the performance of the conveyor system. Experiments for rotations about the axis perpendicular to the olane have also been performed successfully. Work synthesis: - Static modeling under RADIA was developed in order to design the conveyor surface especially for the transitio zone between two neighboring cells. A dynamic modeling under MATLAB allowed to simulate the behavior of single axis motor in open loop and closed loop control. - A conveyor surface prototype, consisting of a multilayer printed circuit board (4 layers) of dimensions 130 mm x 130 mm, was designed under EAGLE software. The influence of the distance between the first two layers was studied using the developed models to ensure uniform displacement in both the directions. - The experimental tests (with LABVIEW interface) of an elementary cell of the intelligent surface with a moving part composed of two orthogonal magnetic motors has been carried out that allowed to validate the operation of the conveying system in both directions of the plane. - Another series of tests with LABVIEW interface were carried out in order to validate experimentally the displacement of the mobile part with the smart surface at the transition zones between the elementary cells. - These experimental tests showed displacements of great extent in the two directions of the plane and of rotation about the axis perpendicular to the plane. - Long displacements and rotations of the moving part were measured using image processing algorithm developed in MATLAB. - At the same time, a high resolution fiber optic displacement sensor was studied that can be integrated into the conveyor surface locally for the precise positioning. A robust signal processing algorithm for high resolution displacement measurement was developed. In this algorithm, - The optimum position of the movable part is determined in order to obtain a continuous switching betwee the two fiber optic probes ; - The usable parts of the signals obtained from two probes were then filtered to measure the displacement using interpolation method ; The algorithm is implemented under MATLAB and validated by the implementation of the experimental signals. The work have been published in an international journal (Computers in Industry (COMIND)) and presented at international congresses (IEEE Sensors, REM Mechatronics, AIM, IWMF) during the years 2011 to 2016
Alrammouz, Rouba. "Conception et réalisation d’un système de détection de gaz à faible coût sur substrat flexible". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS134.
Texto completoCurrent concerns for environmental protection and public health focus on air quality in industries, cities and households. Nowadays, paper-based gas sensors are of increasing interest due to their low cost, biodegradability, flexibility and applications in e-textiles, e-dressings and e-packaging.Graphene oxide is a derivative of graphene with exceptional electrical, mechanical and thermal properties. Graphène oxide is a promising material for the development of low-cost room temperature gas sensors.In this context, this thesis aims to integrate a graphene oxide sensing layer inside a porous paper substrate for humidity and ammonia detection. The first part of this work focuses on the fabrication, functionalization and optimization of capacitive porous gas sensors on paper. A new local reduction process of graphene oxide into electrodes is introduced. The process is hot-plating, a low cost technique compatible with large scale productionThe second part of this work studies the humidity and ammonia sensing capabilities of the sensors. Graphene oxide on paper exhibits a high sensitivity towards ammonia, with humidity as an interfering gas. The local reduction of graphène oxide into electrodes, and its functionalization with zinc oxide increased the sensitivity and selectivity of the device towards humidity. The fabricated sensors exhibit a good repeatability, reproducibility and flexibility
Vergara, Gallego Maria Isabel. "Smarter Radios for Energy efficiency in Wireless Sensor Networks". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENM020/document.
Texto completoThe constraints of Wireless Sensor Networks scenarios require the introduction of optimization techniques at different design levels: from the hardware to the software and communication protocol stack. In fact, the design of energy efficient WSNs involves an appropriate hardware/software co-design oriented to the concerned application. Given the event driven and multitasking nature of WSNs applications, one could think of adding different processing units that cooperate to manage events and tasks in an optimal way. Then, the complexity of tasks performed by the main processing unit can be reduced and energy efficiency can be achieved. In this PhD thesis we study protocols that leverage the implementation of smart radios. The idea of smart radios is introducing intelligence into the radio chip; in this way, it will be able to take decisions and perform several tasks in an autonomous way and without any intervention of the main processing unit. The processing unit will be in charge of bootstrapping the network and, after a stable state is reached, it can remain inactive most of the time while the radio chip provides a given set of services. The proposed protocol is called Wake on Idle and it provides integrated neighborhood maintenance and low duty-cycle medium access control. These services are provided based on analog transmissions that are time encoded; then, as soon as the network enters the stable state (i.e. the topology is formed and nodes are associated and synchronized) digital processing of frames is not needed. Since it relies on low-level information, Wake on Idle can be easily implemented on hardware and integrated into the radio chip; then, it works as a coprocessor that provides high-level services (i.e. neighborhood maintenance and medium access) to the main processing unit. Through theoretical analysis and a preliminary implementation we demonstrate the feasibility of the protocol and we show several interesting characteristics that help achieving energy efficiency and good performance. Then, we further exploit analog signaling to optimize duty cycle of existing medium access control protocols. We propose a mechanism called Sleep on Idle and it is based on the exchange of analog busy tones. Sleep on Idle can also be integrated into the smart radio to take decisions about whether the main processing unit has to be woken up. We apply the decision mechanism to the slotted ieee802.15.4 standard and validate it through simulations and experimentations. The results show an important gain in terms of energy consumption and network reactivity
Leleu, Sylvaine. "Amortissement actif des vibrations d'une structure flexible de type plaque à l'aide de transducteurs piézoélectriques". Cachan, Ecole normale supérieure, 2002. http://www.theses.fr/2002DENS0010.
Texto completoDinh, Thi hong nhung. "Etudes technologiques de composants PDMS pour applications biomédicales : développement de capteurs souples de pression par transfert de film". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS127/document.
Texto completoThis thesis focuses on the development of methodologies dedicated to the development of PDMS-based devices, which are required in medical applications. Two objective applications are considered in this work: i) the development of wearable flexible micro-sensors arrays for measuring pressure fields on human body and ii) the development of a reversible bonding technique of PDMS components dedicated to microfluidic chips. In this work, the mechanical properties of PDMS are determined using experiments and computations; they allow identifying the essential elements of the design of capacitive micro-sensors. The manufacturing process is reliable and reproducible, and different types of flexible pressure sensor have been fabricated by a film transfer process. Electromechanical characterizations show that the fabricated sensors are fully operational and suitable for the intended applications. Normal pressure sensors have a capacitance change ranging from 3 to 17% under a 10 N - 300 kPa - load, which is suitable for dental applications. Fabricated triaxial sensor arrays have a spatial resolution of 25 mm2, and a sensitivity of 4% under 3 N load in compression, and 1.4% / N under shear. These features are suitable for plantar pressure measurements required in gait analyses or for the detection of over-pressures. Besides, two different process methods for the reversible bonding of PDMS devices are developed. The microfluidic devices fabrcitated with these methods can be used within up to 5 “bonding & peeling off” cycles, and can be working at high microfluidic flows (500 µL / min, corresponding to a pressure of 148 kPa). The methodologies developed in these works open the way to the design and fabrication of PDMS-based devices suitable for demanding biomedical applications
Bahoumina, Prince. "Développement d’une plateforme de détection de gaz, utilisant un capteur différentiel flexible imprimé à transducteurs micro-ondes et matériaux composites carbonés". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0101/document.
Texto completoSince the Industrial Revolution, the levels of atmospheric concentrations of greenhouse gases have been increasing, causing an acceleration of global warming. Volatile organic compounds (VOCs) contribute not only to this greenhouse effect, but also to environmental pollution, which has a negative impact on all living species on the planet. For example, in the year 2012, air pollution caused 7 million deaths, according to the World Health Organization (WHO) [1]. In addition, a very recent medical study by the Lancet Commission on Pollution and Health found that one in six deaths in 2015 was related to air and water pollution [2]. Also, indoor and outdoor air pollution is linked to 6.5 million deaths worldwide each year. VOCs can indirectly cause cough, chest discomfort, painful discomfort, shortness of breath, as well as nasal, ocular or throat irritation. They can also be directly toxic or explosive or disruptive of the immune response. In addition, some of them are classified as CMR (carcinogenic, mutagenic and reprotoxic). They are very volatile and often used as solvents for example. In these conditions, a better understanding of the health and environmental effects of exposure to VOCs is necessary. Such knowledge also involves the detection and quantification of VOC concentrations in order to propose a better management of the environments and to alert people in real time of the dangers incurred. Most of the existing or commercially available platforms are either too expensive, energy intensive, high temperature functional, unstable for real-time or long-term detection, which limits the proliferation of measurement sites. This thesis is in the field of dedicated gas sensors for the detection of pollution in the air. It deals with the development of a platform for the detection, monitoring and quantification of volatile organic compounds (VOCs) in real time, using a flexible and printed differential gas sensor based on microwave transducers and composite polymeric carbon materials as sensitive layers. The proposed device aims at providing directly exploitable information such as a low-cost embedded platform dedicated to the Internet of things and which offers increasing possibilities for the proliferation of detection and control sites by realizing networks of wireless communicating sensors operating in various environments
Lubin, Jérôme. "Vers le déploiement d'un réseau de capteurs enfouis dans des multi-plis carbone-epoxy pour l'instrumentation in-situ de structures composites pour l'avionique". Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2199/.
Texto completoManufacturers are using more and more carbon fibers composite materials in their structures. The aviation industry in particular is very interested by these new materials. Carbon fibers are capable of sustaining greater axial strain than their metallic equivalents and are lighter. Their properties allow for the design of more robust and lightweight aircrafts which would in turn bring about lots of benefits: longer lifespan, less fuel consumption, etc. For the time being, aircraft components in carbon composites are oversized for security reasons. Carbon fiber composites are not as good at withstanding torsion and flexion as they are at withstanding axial strain. The lifetimes of the components are not well known and investigation results are not easily transferable from one design to another. In order to ensure operational safety while keeping parts lightweight, health monitoring becomes indispensable. The goal of this PhD thesis is to propose a monitoring solution based on small sensors using silicon technology. These sensors are sensitive to mechanical vibrations and can be used to detect the appearance of faults in the structure. We developed a process which is simple yet robust for manufacturing sensors. The sensitive element is a polysilicon Zener PN. First we demonstrate that the sensors are sensitive to mechanical vibrations. Then we demonstrate the usage of our sensors in monitoring the annealing step in autoclave for carbon fiber polymer pieces. Next step consists in the study of a strong and flexible packaging that can be used with any shape of piece. Finally, we studied the electronic circuits able to read the signal and reduce the background noise
Kervran, Yannick. "Cartographie d'un champ de pression induit par l'occlusion dentaire". Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S077.
Texto completoDental occlusion diagnosis is still a major challenge for dentists. A couple of tools are dedicated to occlusal analysis, such as articulating papers and the T-Scan® system, but they are limited for various reasons. That's why, the goal of this thesis is to develop a novel system consisting in pressure sensor arrays on flexible substrates combining the positive aspects of both previously cited tools: an electronic and computerized system, on a very thin non-invasive flexible substrate. We chose a piezoresistive technology based on microcrystalline silicon strain gauges and 25-µm- or 50-µm-thick Kapton® substrates. Microcrystalline silicon is deposited directly on plastic at low temperature (< 200°C) using PECVD technique (Plasma Enhanced Chemical Vapor Deposition) in a cost-effective solution perspective. Strain gauges have firstly been characterized using bending tests. Longitudinal and transversal gauge factors have been studied in order to understand the behavior of our deposited materials under bending. Those gauges remained functional until strains up to 0.6 % and degradations appeared for higher values. These values correspond to bending radius on the order of 1 mm for 25-µm-thick substrates. Then, those gauges have been integrated in arrays with two different designs: one was an 800-element array to study the occlusal surface of one tooth, and the second was a 6400-element array to study the occlusal surface of a hemiarcade. Those prototypes have showed interesting correlations between articulating paper marks and our electrical responses during characterizations using a dental articulator to simulate a human jaw. Thus, we have developed in this work a proof-of-concept of a flexible strain sensor using microcrystalline silicon dedicated to dental occlusion diagnosis
Decorde, Nicolas. "Développement de jauges de contrainte à base de nanoparticules colloïdales : Application à la réalisation de surfaces tactiles souples". Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0002/document.
Texto completoOne recent big challenge is to implement innovative sensors that take advantage of the unique properties of colloidal nanoparticles chemically synthesized and assembled on various surfaces. The goal of this work is the development of nanoparticle based resistive strain gauges. These strain gauges are constructed of few micrometers wide parallel wires of close packed colloidal gold nanoparticles, chemically synthesized, and assembled on flexible substrates by convective self assembly. The principle of these resistive sensors is based on the tunnel conduction between the adjacent nanoparticles which varies exponentially as the assembly is stretched. Electro-mechanical measurements coupled with scanning electron microscopy and atomic force microscopy observations were used to identify, quantify and understand the impact of the nanoparticle size and the nature of the protecting ligands, on the gauge sensitivity and the drift of the resistance at rest of the nanoparticle based strain gauges. Coupled with small angle x-ray scattering measurements, these studies allowed us to correlate the macroscopic changes in electrical resistance of the strain gauges to the relative displacement of the nanoparticles at the nanoscale. Finally, a matrix of these miniature ultra-sensitive gauges was used to construct flexible touch screen panels capable of measuring the intensity of several touches simultaneously
Zaidi, Houda. "Méthodologies pour la modélisation des couches fines et du déplacement en contrôle non destructif par courants de Foucault : application aux capteurs souples". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00776931.
Texto completoRitou, Mathieu. "Surveillance d'usinage en fraisage de pièces complexes par un suivi de la broche". Phd thesis, Université de Nantes, 2006. http://tel.archives-ouvertes.fr/tel-00355721.
Texto completoTout d'abord, plusieurs critères issus de la bibliographie et susceptibles de résoudre notre problématique, ont été testés dans des conditions de coupe et de trajectoires industrielles, ce qui n'avait pas été fait auparavant. L'analyse de leur comportement a permis de mettre en évidence leurs faiblesses et de faire évoluer notre réflexion, avant de proposer une nouvelle méthode : la Surveillance d'Usinage Intermittente. L'état de l'outil est estimé à partir des efforts de coupe, puis reporté sur une carte de contrôle. Pour plus de fiabilité, seules les zones où la coupe est stable sont surveillées.
Afin d'augmenter la précision, la robustesse et le domaine de validité de la méthode, des améliorations ont ensuite été apportées, quant au conditionnement et à l'analyse des signaux d'efforts. Par ailleurs, les estimations de l'état de l'outil sont affinées pendant l'usinage, grâce à des simulations numériques effectuées au préalable. Des expérimentations ont validé l'approche, par des détections fiables de l'état d'un outil possédant 5 dents (dont une endommagée ou non).
Enfin, nous avons montré que notre méthode permet de détecter de très faibles endommagements de l'outil, survenant au cours de l'usinage d'une pièce. Nous proposons également de coupler notre SSAU à un système d'inspection des outils hors-usinage pour confirmer les détections. Nous avons ensuite montré que notre méthode n'est pas perturbée par l'usure des outils. Une table dynamométrique n'étant pas viable industriellement, nous avons cherché des alternatives. Nous avons finalement montré que la mesure d'efforts peut être réalisée en instrumentant la broche par des capteurs inductifs. L'application de notre méthode permet alors, dans un cadre industriel, de détecter de très faibles endommagements de l'outil, lors de production flexible en fraisage.