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18117
01/06/2018

A review on mechanical considerations for chronically-implanted neural probes

C.BERGAUD, A.LECOMTE, E.DESCAMPS

MEMS, MICA

Revue Scientifique : Journal of Neural Engineering, Vol.15, N°3, Juin 2018 , N° 18117

Lien : https://hal.laas.fr/hal-01764292

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Abstract

This review intends to present a comprehensive analysis of the mechanical considerations for chronically-implanted neural probes. Failure of neural electrical recordings or stimulation over time has shown to arise from foreign body reaction and device material stability. It seems that devices that match most closely with the mechanical properties of the brain would be more likely to reduce the mechanical stress at the probe/tissue interface, thus improving body acceptance. The use of low Young's modulus polymers instead of hard substrates is one way to enhance this mechanical mimetism, though compliance can be achieved through a variety of means. The reduction of probe width and thickness in comparison to a designated length, the use of soft hydrogel coatings and the release in device tethering to the skull, can also improve device compliance. Paradoxically, the more compliant the device, the more likely it will fail during the insertion process in the brain. Strategies have multiplied this past decade to offer partial or temporary stiffness to the device to overcome this buckling effect. A detailed description of the probe insertion mechanisms is provided to analyze potential sources of implantation failure and the need for a mechanically-enhancing structure. This leads us to present an overview of the strategies that have been put in place over the last ten years to overcome buckling issues. Particularly, great emphasis is put on bioresorbable polymers and their assessment for neural applications. Finally, a discussion is provided on some of the key features for the design of mechanically-reliable, polymer-based next generation of chronic neuroprosthetic devices.

143461
18129
28/05/2018

Nanoscale measurements of phosphorous-induced lattice expansion in nanosecond laser annealed germanium

S.BONINELLI, R.MILAZZO, R.CARLES, F.HOUDELLIER, R.DUFFY, K.HUET, A.LA MAGNA, E.NAPOLITANI, F.CRISTIANO

CNR-IMM, Catania, University of Padova, CEMES/CNRS, Tyndall, SCREEN-LASSE, MPN

Revue Scientifique : APL Materials, Vol.6, N°5, 058504p., Mai 2018 , N° 18129

Lien : https://hal.archives-ouvertes.fr/hal-01796115

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Abstract

Laser Thermal Annealing (LTA) at various energy densities was used to recrystallize and activate amorphized germanium doped with phosphorous by ion implantation. The structural modifications induced during the recrystallization and the related dopant diffusion were first investigated. After LTA at low energy densities, the P electrical activation was poor while the dopant distribution was mainly localized in the poly- crystalline Ge resulting from the anneal. Conversely, full dopant activation (up to 1 × 10 20 cm 3 ) in a perfectly recrystallized material was observed after annealing at higher energy densities. Measurements of lattice parameters performed on the fully activated structures show that P doping results in a lattice expansion, with a perpen- dicular lattice strain per atom β Ps = +0.7 ± 0.1 Å 3 . This clearly indicates that, despite the small atomic radius of P compared to Ge, the “electronic contribution” to the lattice parameter modification (due to the increased hydrostatic deformation potential in the conduction band of P doped Ge) is larger than the “size mismatch contribu- tion” associated with the atomic radii. Such behavior, predicted by theory, is observed experimentally for the first time, thanks to the high sensitivity of the measurement techniques used in this work

143594
18160
23/05/2018

Conception et réalisation de microdispositifs électrochimiques, pour l’analyse de l’activité bioénergétique de mitochondries isolées, dans le cadre de la mise au point de traitements innovants des leucémies aiguës myéloïdes

G.LEMERCIER

MICA

Doctorat : Université de Toulouse III - Paul Sabatier, Mai 2018, 179p., Président: L.CASTEILLA, Rapporteurs: P.MAILLEY, R.ROSSIGNOL, Examinateurs: R.FERRIGNO, S.ARBAULT, P.TEMPLE-BOYER, Directeurs de thèse: J.E.SARRY, J.LAUNAY , N° 18160

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The role of mitochondria have been restricted to oxidative phosphorylation for a long time. Now it is clear that they are also the main sources of reactive oxygen species, implied in oxidative stress and cell-to-cell signaling. Thus, mitochondrial malfunction is potentially the cause of the appearance and the progression of diseases linked to ageing like cancers and neurodegenerative troubles. In the frame of acute myeloid leukemia, studies governed by Jean-Emmanuel Sarry of the Cancer Research Center of Toulouse, showed that it is possible to improve the efficacy of current chemotherapies by targeting mitochondria’s function. In this context, the objective of the thesis presented here consist in the design and the manufacturing of electrochemical micro-sensors, dedicated to the analysis of the metabolic activity of isolated mitochondria. The manufacturing occurred in the clean room facilities of the Laboratory for Analysis and Architecture of Systems of Toulouse under the supervision of Jérôme Launay and Pierre Temple-Boyer, researchers specialized in the development of solutions aiming the detection of species diluted in solution. Finally, a complete system ensuring the coupling with microscopy and fluidics have been realized, validated, and patented. The results obtained allow us to consider the analysis at the scale of the single mitochondrion with a parallelized approach, thing that have never been made.

Résumé

La mitochondrie est restée longtemps cantonnée au rôle de centrale énergétique cellulaire. On sait désormais qu’elle est aussi la principale source d’espèces réactives oxygénées, impliquées dans le stress oxydant et la signalisation inter-cellulaire. Le dérèglement de l’activité mitochondriale est ainsi susceptible d’être la cause de l’apparition et de la progression de maladies associées au vieillissement, comme le cancer et les maladies neurodégénératives. Dans le cadre de la leucémie aiguë myéloïde, des études menées par l’équipe dirigée par Jean-Emmanuel Sarry du Centre de Recherche en Cancérologie de Toulouse, ont montré qu’il est possible de sensibiliser les cellules jusqu’alors résistantes à la chimiothérapie, en ciblant préalablement la fonction mitochondriale. C’est dans ce contexte que s’inscrit le sujet de cette de thèse, portant sur la conception et la réalisation de micro-capteurs électrochimiques dédiées à l’analyse du métabolisme mitochondrial, à l’échelle de la mitochondrie isolée. La fabrication des microsystèmes s’est déroulée dans la salle blanche du Laboratoire d’Analyse et d’Architecture des Systèmes de Toulouse, sous l’encadrement des chercheurs Jérôme Launay et Pierre Temple-Boyer, spécialisés dans la conception de capteurs pour la détection d’espèces en phase liquide. Finalement, un système complet assurant le couplage à la microscopie et à la gestion des fluides a été fabriqué, validé, et breveté. Les résultats obtenus nous permettent d’envisager l’analyse à l’échelle de la mitochondrie unique par une approche parallélisée, ce qui n’a encore jamais été réalisé.

143853
18066
01/04/2018

Computational fluid dynamics simulation of the ALD of alumina from TMA and H2O in a commercial reactor

G.P.GAKIS, H.VERGNES, E.SCHEID, C.VAHLAS, B.CAUSSAT, A.BOUDOUVIS

LGC, MPN, CIRIMAT, NTUA

Revue Scientifique : Chemical Engineering Research and Design: Transactions of the Institution of Chemical Engineers Part A, Vol.132, pp.795-811, Avril 2018 , N° 18066

Lien : https://hal.archives-ouvertes.fr/hal-01730196

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A three-dimensional Computational Fluid Dynamics model is built for a commercial Atomic Layer Deposition (ALD) reactor, designed to treat large area 20 cm substrates. The model aims to investigate the effect of the reactor geometry and process parameters on the gas flow and temperature fields, and on the species distribution on the heated substrate surface, for the deposition of Al2O3 films from trimethyl aluminum and H2O. The investigation is performed in transient conditions, without considering any surface reaction. A second CFD model is developed for the feeding system of the reactor, in order to calculate the unknown reactant inlet flow rates. The two models are coupled via a computational strategy dictated by the available experimental measurements. Results show that a purging flow entering the reactor through its loading door affects the flow field above the substrate surface and causes non-uniformity in the temperature and reactants concentration on the substrate surface. During the TMA pulse, a recirculation sets in above the substrate surface, leading to a non-uniform distribution of species on the surface.

142837
18103
29/03/2018

Sub-ppm Nitrogen Dioxide (NO 2 ) Sensor Based on Inkjet Printed CuO on Microhotplate with a Pulsed Temperature Modulation

A.SENDI, G.BESNARD, P.MENINI, C.TALHI, F.BLANC, B.FRANC, M.KHAN, K.FAJERWERG, P.FAU

MICA, I2C, IDEA, LCC

Manifestation avec acte : International Conference on Advances in Sensors, Actuators, Metering and Sensing ( ALLSENSORS ) 2018 du 25 mars au 29 mars 2018, Rome (Italie), Mars 2018, 5p. , N° 18103

Lien : https://hal.laas.fr/hal-01757257

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Nitrogen dioxide (NO 2), a toxic oxidizing gas, is considered among the main pollutants found in atmosphere and indoor air as well. Since long-term or short-term exposure to this gas is deleterious for human health, its detection is an urgent need that requires the development of efficient and cost effective methods and techniques. In this context, copper oxide (CuO) is a good candidate that is sensitive and selective for NO 2 at sub-ppm concentrations. In this work, CuO nanoparticles have been deposited by inkjet printing technology on a micro hotplate that can be operated up to 500°C at low power consumption (55 mW). The optimum detection capacity is obtained thanks to a temperature modulation (two-consecutive temperature steps from 100°C to 500°C), where the sensing resistance is measured. Thanks to this operating mode, we report in this study a very simple method for data processing and exploitation in order to obtain a good selectivity for the nitrogen dioxide over few interferent gases. Only four parameters from the sensor response allow us to make an efficient discrimination between individual or mixed gases in humid atmosphere.

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18056
28/03/2018

Submicron polymer optical waveguides on CYTOP for visible range operation

M.DIEZ GARCIA, S.JOLY, V.RAIMBAULT, J.B.DOUCET, L.OYHENART, L.BECHOU, C.DEJOUS

IMS Bordeaux, MICA, TEAM

Manifestation avec acte : Europtrode ( Europtrode ) 2018 du 25 mars au 28 mars 2018, Naples (Italie), Mars 2018 , N° 18056

Lien : https://hal.archives-ouvertes.fr/hal-01720764

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142797
18073
21/03/2018

Dopant Activation in Ultra-thin SiGeOI and SOI layers characterised by Differential Hall Effect

R.DAUBRIAC, E.SCHEID, S.JOBLOT, R.BENEYTON, P.ACOSTA ALBA, S.KERDILES, F.CRISTIANO

MPN, ST Microelectronics, CEA-LETI

Manifestation avec acte : Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon ( EUROSOI-ULIS ) 2018 du 19 mars au 21 mars 2018, Grenade (Espagne), Mars 2018, 2p. , N° 18073

Lien : https://hal.laas.fr/hal-01735436

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The reduction of the contact resistance RC is one of the most challenging issues related to the miniaturisation of advanced MOSFET architectures, including FDSOI technology (Fully Depleted Silicon-On-Insulator). RC strongly depends on the active dopant concentration at the semiconductor/salicide interface. It is therefore essential that electrical activation at different depths within a doped layer is reliably determined to optimise the fabrication processes. In this paper, we firstly present a Differential Hall Effect (DHE) method which allows measuring the active dopant concentration profile close to the surface with nm resolution for ultra-shallow doped Si1-xGex and Si layers. Then, we present DHE measurements made on junctions processed with advanced techniques, including nsec LTA and msec DSA anneals.

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18145
19/03/2018

Conception d’un système d’analyse multi-capteur ISFET pour la surveillance in situ de l’azote minéral. Application à la culture du blé dur

M.JOLY

MICA

Doctorat : INSA de Toulouse, 19 Mars 2018, 184p., Président: J.Y.FOURNIOLS, Rapporteurs: W.WROBLEWSKI, F.LE BIHAN, Examinateurs: T.TALLEC, S.HOUOT, Directeurs de thèse: P.TEMPLE BOYER, J.LAUNAY , N° 18145

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Abstract

Excessive use of nitrogen fertilizers in modern agricultural practices is a concern as it leads to groundwater pollution and eutrophication of fresh and marine waters. Soil testing can enable the introduction of new agricultural practices that take more into account temporal and local variations of soil and plants. This work therefore aims at the development of an in situ, autonomous and communicating analysis system for real-time monitoring of the mineral nitrogen contents of soils. Our system is based on the Ion-Sensitive Field Effect Transistor (ISFET) microsensor technology. A first step of its development was dedicated to the fabrication of generic pH-ISFET microsensors. The problem of determining soil pH by inserting pH-ISFETs directly into the soil was considered. Results obtained by this in situ method were compared with the standard method and we examined the influence of soil (moisture, texture, pH) and ISFET parameters (lifetime, time drift). In a second step, pNH4-ISFET and pNO3-ISFET chips were obtained by functionalizing the generic pH-ISFET chips with ionosensitive membranes. The composition of these membranes has been optimized until detection properties (sensitivity, selectivity, stability, etc.) were in good accordance with the ammonium and nitrate ion contents of cultivated soils. Characterizations under in situ conditions were then carried out. Finally, the integration in the ground, the protection, the power supply and the remote communication of the sensors were made possible by the integration in a dedicated system. We obtained promising results.

Résumé

L’usage excessif de fertilisants azotés dans les pratiques agricoles modernes est préoccupant car il aboutit, entre autres, à la pollution des nappes phréatiques et à l’eutrophisation des eaux douces et marines. L’analyse du sol peut faciliter la mise en place de nouvelles pratiques agricoles qui tiennent davantage compte des variations temporelles et locales du sol et des plantes. Ces travaux visent donc le développement d’un système d’analyse in situ, autonome et communicant pour le suivi en temps réel des teneurs en azote minéral du sol. Notre système est basé sur la technologie de microcapteur chimique en silicium Ion- Sensitive Field Effect Transistor (ISFET). Une première phase de son développement a été dédiée à la fabrication de microcapteurs génériques pH-ISFET. La problématique de la détermination du pH du sol en insérant les pH-ISFET directement dans le sol a été considérée. Les résultats obtenus par cette méthode in situ ont été comparés avec la méthode standard et nous avons examiné l’influence de paramètres propres au sol (humidité, texture, pH) et à l’ISFET (durée de vie, dérive temporelle). Dans un second temps, des puces pNH4-ISFET et pNO3-ISFET ont été obtenues en fonctionnalisant les puces génériques pH-ISFET grâce à l'intégration de membranes ionosensibles. La composition de ces membranes a été optimisée jusqu’à obtention de propriétés de détection (sensibilité, sélectivité, stabilité…) en adéquation avec les teneurs en ions ammonium et nitrates typiques des sols cultivés. Des premières caractérisations en conditions in situ ont alors été effectuées. Finalement, les capteurs ont été intégrés à un système permettant l’insertion des capteurs dans le sol, leur protection, l’alimentation électrique par batterie et la communication à distance des données de mesure. De premiers résultats, prometteurs, ont été obtenus.

Mots-Clés / Keywords
ISFET; Agriculture; Analyse in situ du sol; Membranes ionosensibles; Intégration; Capteurs autonomes communicants; Cycle de l’azote; Microfabrication; In situ soil analysis; Ionosensitive membranes; Integration; Autonomous and communicating sensors; Nitrogen cycle;

143793
18068
14/03/2018

A Differential Hall Effect method with sub-nanometre resolution for active dopant concentration profiling in ultra-thin Si 1-x Ge x and Si doped layers

R.DAUBRIAC, E.SCHEID, S.JOBLOT, R.BENEYTON, P.ACOSTA ALBA, S.KERDILES, F.CRISTIANO

MPN, ST Microelectronics, CEA-LETI

Rapport LAAS N°18068, Mars 2018, 34p.

Lien : https://hal.laas.fr/hal-01730674

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In this paper, we present an enhanced Differential Hall Effect method (DHE) for Si and SiGe ultrathin layers for the investigation of dopant activation in the surface region with sub-nanometre resolution. In the case of SiGe case, which constitutes the most challenging process, we show the reliability of the SC1 chemical solution (NH4OH:H2O2:H2O) thanks to its slow etch rate, stoichiometry conservation and low roughness generation. The reliability of a complete DHE procedure, with an etching step as small as 0.5 nm, is demonstrated on a dedicated 20 nm-thick SiGe test structure fabricated by CVD and uniformly doped in situ during growth. The developed method is finally applied to the investigation of dopant activation achieved by advanced annealing methods (including millisecond and nanosecond laser anneal) in two material systems: 6 nm-thick SiGeOI and 11 nm-thick SOI. In both cases, DHE is shown to be a unique sensitive characterisation technique for a detailed investigation of dopant activation in ultra-shallow layers, providing sub-nm resolution for both dopant concentration and carrier mobility depth profiles.

142839
18104
13/03/2018

Bone degradation machinery of osteoclasts: An HIV-1 target that contributes to bone loss

B.RAYNAUD-MESSINA, L.BRACQ, M.DUPONT, S.SOURIANT, S.M.USMANI, A.PROAG, K.PINGRIS, V.SOLDAN, C.THIBAULT, F.CAPILLA, T.AL SAATI, I.GENNERO, P.JURDIC, P.JOLICOEUR, J.L.DAVIGNON, T.R.MEMPEL, S.BENICHOU, I.MARIDONNEAU-PARINI, C.VEROLLET

IPBS, INSERM, Paris, Harvard Medical Sch, Multiscale Electron, ELIA, INSERM, Centre de Physiopathologie, ENS Lyon, IRCM, Montreal

Revue Scientifique : Proceedings of the National Academy of Sciences, Vol.115, N°11, pp.E2556-E2565, Mars 2018 , N° 18104

Lien : https://hal.laas.fr/hal-01764831

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Bone deficits are frequent in HIV-1–infected patients. We report here that osteoclasts, the cells specialized in bone resorption, are infected by HIV-1 in vivo in humanized mice and ex vivo in human joint biopsies. In vitro, infection of human osteoclasts occurs at different stages of osteoclastogenesis via cell-free viruses and, more efficiently, by transfer from infected T cells. HIV-1 infection markedly enhances adhesion and osteolytic activity of human osteoclasts by modifying the structure and function of the sealing zone, the osteoclast-specific bone degradation machinery. Indeed, the sealing zone is broader due to F-actin enrichment of its basal units (i.e., the podosomes). The viral protein Nef is involved in all HIV-1–induced effects partly through the activation of Src, a regulator of podosomes and of their assembly as a sealing zone. Supporting these results, Nef-transgenic mice exhibit an increased osteoclast density and bone defects, and osteoclasts derived from these animals display high osteolytic activity. Altogether, our study evidences osteoclasts as host cells for HIV-1 and their pathological contribution to bone disorders induced by this virus, in part via Nef.

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