464 research outputs found

    0-level Vacuum Packaging RT Process for MEMS Resonators

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    A new Room Temperature (RT) 0-level vacuum package is demonstrated in this work, using amorphous silicon (aSi) as sacrificial layer and SiO2 as structural layer. The process is compatible with most of MEMS resonators and Resonant Suspended-Gate MOSFET [1] fabrication processes. This paper presents a study on the influence of releasing hole dimensions on the releasing time and hole clogging. It discusses mass production compatibility in terms of packaging stress during back-end plastic injection process. The packaging is done at room temperature making it fully compatible with IC-processed wafers and avoiding any subsequent degradation of the active devices.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    Designing Vibrotactile Widgets with Printed Actuators and Sensors

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    Physical controls are fabricated through complicated assembly of parts requiring expensive machinery and are prone to mechanical wear. One solution is to embed controls directly in interactive surfaces, but the proprioceptive part of gestural interaction that makes physical controls discoverable and usable solely by hand gestures is lost and has to be compensated, by vibrotactile feedback for instance. Vibrotactile actuators face the same aforementioned issues as for physical controls. We propose printed vibrotactile actuators and sensors. They are printed on plastic sheets, with piezoelectric ink for actuation, and with silver ink for conductive elements, such as wires and capacitive sensors. These printed actuators and sensors make it possible to design vibrotactile widgets on curved surfaces, without complicated mechanical assembly

    Identification of diverse database subsets using property-based and fragment-based molecular descriptions

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    This paper reports a comparison of calculated molecular properties and of 2D fragment bit-strings when used for the selection of structurally diverse subsets of a file of 44295 compounds. MaxMin dissimilarity-based selection and k-means cluster-based selection are used to select subsets containing between 1% and 20% of the file. Investigation of the numbers of bioactive molecules in the selected subsets suggest: that the MaxMin subsets are noticeably superior to the k-means subsets; that the property-based descriptors are marginally superior to the fragment-based descriptors; and that both approaches are noticeably superior to random selection

    La demeure seigneuriale dans l’espace Plantagenêt : salles, chambres et tours

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    Le gros ouvrage que nous proposent les Presses universitaires de Rennes et un groupe de travail informel franco-anglais sur l’habitat seigneurial (xie-xve siècles) mérite toute notre attention pour la masse d’informations délivrées sur un sujet qui a connu un sérieux renouveau depuis une quarantaine d’années sous l’impulsion notable des chercheurs britanniques qui ont fait de la Bretagne (Meirion-Jones) et de la Normandie (Impey) un champ de recherche renou..

    La perspectiva de género y la función del discurso en la construcción del personaje femenino en Mauprat de George Sand

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    La perspectiva de género y la función del discurso en la construcción del personaje femenino en Mauprat de George San

    Silicon on Nothing Mems Electromechanical Resonator

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    The very significant growth of the wireless communication industry has spawned tremendous interest in the development of high performances radio frequencies (RF) components. Micro Electro Mechanical Systems (MEMS) are good candidates to allow reconfigurable RF functions such as filters, oscillators or antennas. This paper will focus on the MEMS electromechanical resonators which show interesting performances to replace SAW filters or quartz reference oscillators, allowing smaller integrated functions with lower power consumption. The resonant frequency depends on the material properties, such as Young's modulus and density, and on the movable mechanical structure dimensions (beam length defined by photolithography). Thus, it is possible to obtain multi frequencies resonators on a wafer. The resonator performance (frequency, quality factor) strongly depends on the environment, like moisture or pressure, which imply the need for a vacuum package. This paper will present first resonator mechanisms and mechanical behaviors followed by state of the art descriptions with applications and specifications overview. Then MEMS resonator developments at STMicroelectronics including FEM analysis, technological developments and characterization are detailed.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    Deux approches pédagogiques dans la prévention du paludisme par le pharmacien d'officine

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    Les voyageurs se rendant dans certains pays ou régions du monde ont un risque de développer le paludisme. Il s agit d une maladie infectieuse à transmission vectorielle causée par un parasite appartenant au genre Plasmodium. Le paludisme est une maladie grave, parfois mortelle, très répandue dans les pays tropicaux et subtropicaux. Le pharmacien d officine a un rôle central et primordial dans le conseil aux voyageurs et dans la prévention de l'infestation. L information donnée doit être fiable, complète et actualisée. Pour fournir les informations aux pharmaciens mais aussi aux étudiants de la nouvelle génération Y, deux approches pédagogiques seront utilisées dans cette thèse. L une traditionnelle, l autre plus adaptée aux attentes et aux habitudes de la nouvelle génération appelée : approche par étude de cas.People who travel in specific countries or areas can be exposed and can develop malaria. It is a mosquito-borne infectious disease caused by parasitic protozoans of the genus Plasmodium. Malaria is a serious and sometimes fatal disease which is widespread in many tropical and subtropical countries. The pharmacist has a central role in the prevention of the disease by giving advices to traverlers. The information must be reliable, complete and up-to-date. The thesis will be developped into two pedagogical approaches to give the right information to the pharmacists and also to Y generation students. The first one is a traditional synthesis work. The second is a new methode : a study case, that fits more with student s expectations and habits.GRENOBLE1-BU Médecine pharm. (385162101) / SudocSudocFranceF

    Tuneable Capacitor based on dual picks profile of the sacrificial layer

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    In this paper, we present a novel dual gap tuneable capacitor process based on the profile of the sacrificial layer. This profile involves a tri-layer photo-resist process with only one mask level. This realization is based on a special profile of the sacrificial layer designed by two picks. The mechanism of the sacrificial layer realisation is dependent on resist thickness, resist formulation (viscosity, type of polymer and/or solvent, additives...), design of the patterned layer (size or width) and the conditions under which this layer is prepared: thermal treatment, etch back processes... In this communication we demonstrate influence of the later parameters and discuss how a dual pick profile was achieved.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    Antireflection of an absorbing substrate by an absorbing thin film at normal incidence

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    An absorbing substrate of complex refractive index n2 - jk2 at wavelength λ can be coated by an absorbing thin film of complex refractive index n1 - jk1 and thickness d to achieve zero reflection at normal incidence. For given n2,k2 multiple solutions (n1,k1,d/λ) are found that correspond to infinitely many distinct antireflection layers. This is demonstrated for a Si substrate at two wavelengths (6328 and 4420 Å). The response of these absorbing antireflection layers to changes of the angle of incidence from 0 to 45° and to changes of thickness of ±10% is also determined and compared to the limting case of a nonabsorbing antireflection layer

    MEMS tunable capacitors with fragmented electrodes and rotational electro-thermal drive

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    This paper reports on the design, simulation and fabrication of tunable MEMS capacitors with fragmented metal (AlSi 4%) electrodes. We examine a rotational electro-thermal actuation. An analytic model of the rotational effect thermal actuator was established in order to show the periodicity of the capacitance when the angle increases. Evaluation of the impact of fringing fields on the capacitance has been carried out using finite element analysis (FEA). The MEMS capacitors were fabricated using metal surface micromachining with polyimide sacrificial layer. The maximum rotation, corresponding to a maximum angle of 7°, was obtained near 1.2V and 299mA. The proposed capacitor has a practical tuning range of 30%. FEA has shown that this figure can be improved with design optimization. The MEMS architecture based on rotational effect and fragmented electrodes does not suffer from the pull in effect and offers a practical solution for future above-IC capacitor
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