240 results on '"M. Le Berre"'
Search Results
2. 237 IS ONLINE GROUP-BASED PELVIC FLOOR MUSCLE TRAINING FEASIBLE FOR OLDER WOMEN WITH URINARY INCONTINENCE?
- Author
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M Le Berre, J Filiatrault, B Reichetzer, and C Dumoulin
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Diseases of the genitourinary system. Urology ,RC870-923 - Published
- 2022
- Full Text
- View/download PDF
3. Photodetection and Photostatistics
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M Le Berre
- Subjects
Physics ,business.industry ,Optoelectronics ,Photodetection ,business - Published
- 2020
4. Investigation of the in-plane and out-of-plane electrical properties of metallic nanoparticles in dielectric matrix thin films elaborated by atomic layer deposition
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Daniel Thomas, Lucian Roiban, A Malchère, L. Militaru, Etienne Puyoo, M. Le Berre, David Albertini, Thierry Epicier, Siddardha Koneti, Francis Calmon, Andrei Sabac, INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), INL - Plateforme Technologique Nanolyon (INL - Nanolyon), and ANR-11-IDEX-0007,Avenir L.S.E.,PROJET AVENIR LYON SAINT-ETIENNE(2011)
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Electron mobility ,Materials science ,Analytical chemistry ,Bioengineering ,02 engineering and technology ,01 natural sciences ,Atomic layer deposition ,Planar ,0103 physical sciences ,General Materials Science ,Electrical and Electronic Engineering ,Thin film ,010302 applied physics ,metallic nanoparticles ,Condensed matter physics ,Mechanical Engineering ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,shadow edge evaporation ,General Chemistry ,021001 nanoscience & nanotechnology ,Evaporation (deposition) ,Mechanics of Materials ,atomic layer deposition ,electrical properties ,Electrode ,0210 nano-technology ,Current density ,Order of magnitude - Abstract
International audience; Pt nanoparticles in a Al2O3 dielectric matrix thin films are elaborated by means of atomic layer deposition. These nanostructured thin films are integrated in vertical and planar test structures in order to assess both their in-plane and out-of-plane electrical properties. A shadow edge evaporation process is used to develop planar devices with electrode separation distances in the range of 30 nm. Both vertical and planar test structures show a Poole–Frenkel conduction mechanism. Low trap energy levels (
- Published
- 2017
5. Fluorescence eXclusion Measurement of volume in live cells
- Author
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C, Cadart, E, Zlotek-Zlotkiewicz, L, Venkova, O, Thouvenin, V, Racine, M, Le Berre, S, Monnier, and M, Piel
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Cell Tracking ,Cell Cycle ,Single-Cell Analysis ,Cell Shape ,Cell Size ,Fluorescent Dyes - Abstract
Volume is a basic physical property of cells; however, it has been poorly investigated in cell biology so far, mostly because it is difficult to measure it precisely. Recently, large efforts were made to experimentally measure mammalian cell size and used mass, density, or volume as proxies for cell size. Here, we describe a method enabling cell volume measurements for single living cells. The method is based on the principle of fluorescent dye exclusion and can be easily implemented in cell biology laboratories. As this method is very versatile, it can be used for cells of different sizes, adherent or growing in suspension, over several cell cycles and is independent of cell shape changes. The method is also compatible with traditional cell biology tools such as epifluorescence imaging or drug treatments.
- Published
- 2017
6. Fluorescence eXclusion Measurement of volume in live cells
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Larisa Venkova, Matthieu Piel, Olivier Thouvenin, Sylvain Monnier, Ewa Zlotek-Zlotkiewicz, Clotilde Cadart, M. Le Berre, and Victor Racine
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0301 basic medicine ,Dye exclusion ,Biology ,Cell cycle ,Fluorescence ,Cell size ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Volume (thermodynamics) ,Mammalian cell ,Fluorescence microscope ,Cell shape ,Biological system ,030217 neurology & neurosurgery - Abstract
Volume is a basic physical property of cells; however, it has been poorly investigated in cell biology so far, mostly because it is difficult to measure it precisely. Recently, large efforts were made to experimentally measure mammalian cell size and used mass, density, or volume as proxies for cell size. Here, we describe a method enabling cell volume measurements for single living cells. The method is based on the principle of fluorescent dye exclusion and can be easily implemented in cell biology laboratories. As this method is very versatile, it can be used for cells of different sizes, adherent or growing in suspension, over several cell cycles and is independent of cell shape changes. The method is also compatible with traditional cell biology tools such as epifluorescence imaging or drug treatments.
- Published
- 2017
7. Metallic nanoparticle-based strain sensors elaborated by atomic layer deposition
- Author
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M. Le Berre, Daniel Thomas, Annie Malchere, Matthieu Bugnet, M. R'Mili, C. Malhaire, Siddardha Koneti, Lucian Roiban, Andrei Sabac, Rémi Rafael, Etienne Puyoo, INL - Dispositifs Electroniques ( INL - DE ), Institut des Nanotechnologies de Lyon ( INL ), École Centrale de Lyon ( ECL ), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon ( CPE ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ) -École Centrale de Lyon ( ECL ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Matériaux, ingénierie et science [Villeurbanne] ( MATEIS ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique ( CNRS ) -Institut National des Sciences Appliquées de Lyon ( INSA Lyon ), Université de Lyon-Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ), INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
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Wheatstone bridge ,Physics and Astronomy (miscellaneous) ,[ SPI.MAT ] Engineering Sciences [physics]/Materials ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,Bending ,01 natural sciences ,law.invention ,[SPI.MAT]Engineering Sciences [physics]/Materials ,Atomic layer deposition ,law ,0103 physical sciences ,Composite material ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Strain gauge ,010302 applied physics ,Physics ,[PHYS]Physics [physics] ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,[ PHYS ] Physics [physics] ,[ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics] ,021001 nanoscience & nanotechnology ,Pressure sensor ,Gauge factor ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,[ SPI.NANO ] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[ SPI.OPTI ] Engineering Sciences [physics]/Optics / Photonic ,0210 nano-technology ,Short circuit - Abstract
International audience; Platinum nanoparticle-based strain gauges are elaborated by means of atomic layer deposition on flexible polyimide substrates. Their electro-mechanical response is tested under mechanical bending in both buckling and conformational contact configurations. A maximum gauge factor of 70 is reached at a strain level of 0.5%. Although the exponential dependence of the gauge resistance on strain is attributed to the tunneling effect, it is shown that the majority of the junctions between adjacent Pt nanoparticles are in a short circuit state. Finally, we demonstrate the feasibility of an all-plastic pressure sensor integrating Pt nanoparticle-based strain gauges in a Wheatstone bridge configuration.
- Published
- 2017
8. Validity of urine dipstick test to assess eradication of urinary tract infection in persons with spinal cord injury
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M. Le Berre, J.-G. Previnaire, P. Denys, L. Pawlicki, L. Chouaki, J.-M. Soler, and E. Hode
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Male ,medicine.medical_specialty ,Bacteriuria ,medicine.drug_class ,Urology ,Urinary system ,Population ,Antibiotics ,Urine ,Urinalysis ,urologic and male genital diseases ,03 medical and health sciences ,0302 clinical medicine ,Predictive Value of Tests ,Internal medicine ,Intermittent catheterisation ,medicine ,Humans ,030212 general & internal medicine ,Prospective Studies ,education ,Spinal cord injury ,Spinal Cord Injuries ,education.field_of_study ,business.industry ,Dipstick ,medicine.disease ,Surgery ,Anti-Bacterial Agents ,Female ,business ,030217 neurology & neurosurgery - Abstract
Summary Objectives To prospectively study the predictive value (PV) of urine nitrite (NIT) dipstick testing against urine cultures during antibiotic treatment for urinary tract infection (UTI), and other situations, in patients with spinal cord injury (SCI). Methods Inpatients with SCI on intermittent catheterisation (IC) or a Foley indwelling catheter (FC) were included. Urine specimens were collected in patients without symptoms (routine), with symptoms of UTI (suspicion), and on day 4 of a 5-day antibiotic treatment (ATB + 3). Results A total of 157 urine samples were collected in 61 patients: 34 were on IC (95 samples) and 27 on FC (62 samples). The prevalence of asymptomatic bacteriuria in the urine cultures was 89% in routine (70 samples). At ATB + 3, microbiological cure was found in 27/30 specimens (IC group) and 2/6 (FC group). In the routine condition, the specificity and positive PV of the NIT tests was 1.00 and sensitivity 0.63. The negative PV was low in both groups. In suspicion of UTI, the sensitivity was between 0.69 and 0.55, the positive PV was 1.00 and the negative PV 0.00 for both groups. At ATB + 3, the negative PV and sensitivity was 1.00, specificity 0.85 and positive PV 0.43 in the IC group, and in the FC group, specificity was 1.00, negative PV 0.33 and sensitivity 0.00. Conclusion In the SCI population on intermittent or indwelling catheters with high prevalence of bacteriuria, dipstick testing helped assess the eradication of germs during antibiotic treatment, but showed no value in the decision making process for UTI. Level of evidence 3.
- Published
- 2016
9. Nonlinearity and nonequilibrium together in Nature: wind waves in the open ocean
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M. Le Berre and Yves Pomeau
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Physics ,Classical mechanics ,Inviscid flow ,Wind wave ,Mechanics ,Gravity wave ,Mechanical wave ,Physics::Atmospheric and Oceanic Physics ,Atomic and Molecular Physics, and Optics ,Wind speed ,Swell ,Longitudinal wave ,Dimensionless quantity - Abstract
We derive scaling laws for the steady spectrum of wind excited waves, neglecting surface tension and taking air and water as inviscid, an approximation valid at large wind speed. Independently of the wind speed, there exists an unique (small) dimensionless parameter ϵ, the ratio of the mass densities of the two fluids (air and water). The smallness of ϵ allows to derive some important average properties of the wave system. The average square slope of the waves is, as observed, a small but not very small quantity, because it is of order |ln(ϵ 2)|-1. This supports the often used assumption of small nonlinearity in the wave-wave interaction. We introduce an equation to be satisfied by the two-point correlation of the height fluctuations. Lastly we reconsider the formation of swell, that is the relationship between the randomness of waves and the observation of quasi monochromatic water waves.
- Published
- 2010
10. Twenty-seventh year of the Alpine marmot introduction in the agricultural landscape of the Central Massif (France)
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R. Ramousse, M. le Berre, and J. Metral
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Marmota marmota ,geography ,education.field_of_study ,geography.geographical_feature_category ,biology ,Ecology ,Population size ,Population ,Introduced species ,Marmot ,Massif ,biology.organism_classification ,Dry stone ,Animal Science and Zoology ,Wildlife management ,education ,Ecology, Evolution, Behavior and Systematics - Abstract
A small population of Alpine marmots was introduced near the top of the Mezenc Massif (France) in 1980 and reinforced 7 times until 1991. An annual monitoring was performed since 1988. It took 12 years to the population size to reach the number of marmots released. Afterwards the population doubled every 7 years, despite several population crashes (in 1997 and 2001). The currently censused 492 marmots were distributed into 86 sites on an area of about 200 km2 in 2007. A Multiple Correspondence Analysis of demographic and environmental parameters of each site showed that marmots preferred, these last years, anthropogenic sites (meadows, dry stone walls, elevation under 1200 m) where reproduction rate was highest. Thus, marmots are now competing with farmers for space. In the same time, tourism increased strongly, especially tourism related to marmot spotting. The interactions between the presence of marmots in this agricultural environment and human activities are described, and their consequences are cons...
- Published
- 2009
11. Microfluidic device for protein crystallization under controlled humidity
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M. Le Berre, M. Lounaci, Yong Chen, P. Rigolet, and C. Abraham
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Materials science ,Microfluidics ,Evaporation ,Nanotechnology ,Integrated circuit ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Microcontact printing ,Electrical and Electronic Engineering ,Crystallization ,Contact print ,Protein crystallization ,Lithography - Abstract
Crystallization is one of the key steps for the determination of a protein structure by X-ray diffraction. Microfluidics offers new perspectives for high throughput screening of the crystallization conditions with much reduced cost. In particular, fast prototyping of microfluidic devices by soft-lithography using PDMS has lead to successful demonstrations of both on chip crystallisation and large scale integration. However, PDMS, which is gas permeable, can lead irreversibly to the liquid evaporation in microfluidic chambers. Because of the fragility of the protein crystals, this is clearly undesirable for post-crystallization experiments. We describe here a simple but yet efficient approach to solve this problem, where the PDMS device is placed inside a small tight box having two compartments separated with a thin membrane. Inside the box, a good control of humidity can be achieved and protein crystals could be conserved over a long period without dehydratation.
- Published
- 2007
12. Micro-aspiration assisted lithography
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M. Le Berre, Yong Chen, C. Crozatier, G. Velve Casquillas, and Jian Shi
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Materials science ,Nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nanoimprint lithography ,law.invention ,Resist ,law ,X-ray lithography ,Electrical and Electronic Engineering ,Photolithography ,Lithography ,Layer (electronics) ,Next-generation lithography ,Electron-beam lithography - Abstract
We report on a micro-fabrication method based on micro-aspiration assisted lithography (MAAL). Unlike nanoimprint lithography where a mould is pressed into a resist layer spin coated on a substrate, MAAL uses aspiration forces to guide the resist material in the mould cavities. By suing this technique, the limit of capillary based lithography techniques has been extended. Double layer PDMS moulds were fabricated using multi-layer soft-lithography in which a micro-aspiration network could be introduced close to the pattern layer of the mould. As a result, high resolution patterning could be obtained with a UV curable resist. We also show the results of patterning of a thin layer of PDMS, nano-particles as well as agar gels. We have also provided a semi-quantitative analysis in order to understand the limitation of different approaches.
- Published
- 2007
13. Reversible assembling of microfluidic devices by aspiration
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G. Velve Casquillas, C. Crozatier, Yong Chen, and M. Le Berre
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Channel network ,Materials science ,Fabrication ,Microfluidics ,Nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Anode ,Microfluidic channel ,Surface modification ,Electrical and Electronic Engineering ,Injection pressure ,Leakage (electronics) - Abstract
This paper deals with a novel and flexible method for microfluidic device assembling. In general, microfluidic device assembly is obtained by irreversible sealing with anodic, thermal or chemical bonding. Reversible assembly can be obtained by aspiration through a crossing channel network (CCN) between the two pieces of microfluidic device (channels and substrate). In this way, relatively high injection pressure can be achieved in microfluidic channels without leakage. We describe the principle and the fabrication of such PDMS devices and also show two examples of the described assembly method applied to surface functionalization.
- Published
- 2006
14. Electrocapillary force actuation of microfluidic elements
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C. Crozatier, M. Le Berre, Z. L. Zhang, and Yong Chen
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Fabrication ,Materials science ,Microfluidics ,Nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Surface tension ,Microelectrode ,Membrane ,law ,Microfluidic channel ,Electrical and Electronic Engineering ,Spark plug ,Lithography - Abstract
Electrocapillary force can be used to displace a mercury droplet confined in microfluidic channels. When the plug is moved into an area of a thin membrane of low Young's module, the surface tension of the confined mercury droplet provides a force to deform the membrane. We show that this effect, together with the electrocapillary force controlled movement, can be used for the actuation of microfluidic elements. We applied this technique to micro valves obtained by using multilayer soft-lithography techniques. Fabrication of integrated microelectrodes as well as single and multiple mercury plugs using microfluidic techniques has also been shown, thereby providing a set of technology for more detailed investigations.
- Published
- 2005
15. In situ bio-functionalization and cell adhesion in microfluidic devices
- Author
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C. Crozatier, M. Le Berre, Yong Chen, and Z. L. Zhang
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Materials science ,Cell adhesion molecule ,Microfluidics ,Nanotechnology ,Adhesion ,Lab-on-a-chip ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Soft lithography ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Bio-MEMS ,Surface modification ,Electrical and Electronic Engineering ,Cell adhesion - Abstract
Protein immobilization is of great importance for the development of biosensors, immunoassays and microfluidic devices. In this work, we study the in situ bio-functionalization and cell adhesion in microfluidic channels. A way of covalently linking antibodies on the channel surface while keeping their bio-functionality and its application for efficient cell adhesion were shown. Soft lithography has been used to fabricate simple microfluidic devices and all chemical and biologic materials were injected into microfluidic channels for the in situ bio-functionalization and cell adhesion. Our results show that the established bio-processing protocol significantly enhances the protein immobilization on both glass and poly-dimethylsiloxane surfaces, thereby allowing one to develop a large number of applications.
- Published
- 2005
16. YIG thin films for magneto‐optical and microwave applications
- Author
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S. Capraro, T. Boudiar, Jean Jacques Rousseau, Béatrice Payet-Gervy, M.-F. Blanc-Mignon, T. Rouiller, M. Le Berre, Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,010302 applied physics ,Materials science ,Annealing (metallurgy) ,business.industry ,Isolator ,Yttrium iron garnet ,Gadolinium gallium garnet ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Sputtering ,0103 physical sciences ,Faraday effect ,symbols ,Optoelectronics ,Thin film ,0210 nano-technology ,business ,ComputingMilieux_MISCELLANEOUS ,Microwave - Abstract
Thin films of Yttrium Iron Garnet (YIG) are grown by radio frequency magnetron non reactive sputtering system on quartz and Gadolinium Gallium Garnet (GGG) for optical applications or alumina substrates for microwave applications. A post deposition annealing is needed to obtain the crystallization of YIG films and the magnetic properties which are correlated with the magneto-optical properties. Their crystallographic, morphologic and magnetic properties are explored. The variation of Faraday rotation is studied versus the wavelength. For both optical substrates, quartz and GGG, results are comparable with the literature for bulk material. A microwave isolator was realized with YIG thin film on alumina substrate in a coplanar configuration. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
- Published
- 2004
17. Properties of barium ferrite sputtered films
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M. Le Berre, Bernard Bayard, S. Capraro, D. Barbier, H. Joisten, J.P. Chatelon, E. Mery, Jean Jacques Rousseau, Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Jean Monnet - Saint-Étienne (UJM), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Silicon ,Scanning electron microscope ,Annealing (metallurgy) ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Nuclear magnetic resonance ,law ,0103 physical sciences ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Electrical and Electronic Engineering ,Crystallization ,Composite material ,Instrumentation ,ComputingMilieux_MISCELLANEOUS ,Barium ferrite ,010302 applied physics ,Metals and Alloys ,Sputter deposition ,Coercivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,chemistry ,0210 nano-technology - Abstract
Ferrites have magnetic properties suitable for electronic applications, especially in the microwave range (circulators and isolators). Hexagonal ferrite, such as barium ferrite (BaFe12O19 or BaM), are of great interest for microwave device applications because of their large resistivity and high permeability at high frequencies. BaM films, 1–10 μm thick, were deposited under optimized conditions by RF magnetron sputtering on alumina and silicon substrates. After deposition, films were amorphous and needed a post-deposition annealing at 800 °C to crystallize and to present magnetic properties. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results showed that BaM films deposited on alumina and silicon substrates presented a good crystallization, a smooth surface and no cracks. Ba, Fe and O depth profiles obtained by secondary ion mass spectroscopy (SIMS) showed that the films have a good in-depth uniformity. The film residual stress was evaluated using curvature measurements. Whatever the substrate type, the films are in compression after deposition. Upon annealing and crystallization, a tensile stress adds up in relation with crystalline arrangements. Finally, regarding the magnetic properties measured using a vibrating sample magnetometer (VSM), the optimized saturation magnetization of such films reached 500 mT and the coercive force 325 kA/m. These values are close to that of the bulk BaM.
- Published
- 2004
18. Moving localized structures and spatial patterns in quadratic media with a saturable absorber
- Author
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M. Le Berre, Majid Taki, Andree Tallet, L. Di Menza, E Reyssayre, and Mustapha Tlidi
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Hopf bifurcation ,Physics ,Physics and Astronomy (miscellaneous) ,business.industry ,Degenerate energy levels ,Pattern formation ,Saturable absorption ,Instability ,Molecular physics ,Atomic and Molecular Physics, and Optics ,symbols.namesake ,Optics ,Mean field theory ,symbols ,Optical parametric oscillator ,business ,Lasing threshold - Abstract
For near the first lasing threshold, we give a detailed derivation of a real order parameter equation for the degenerate optical parametric oscillator with a saturable absorber. For this regime, we study analytically the role of the quasi-homogeneous neutral mode in the pattern formation process. We show that this effect stabilized the hexagonal patterns below the lasing threshold. More importantly, we find numerically that when Turing and Hopf bifurcations interact, a stable moving asymmetric localized structure with a constant transverse velocity is generated. The formation of the moving localized structures is analysed for both the propagation and the mean field models. A quantitative confrontation of the two models is discussed.
- Published
- 2004
19. Fabrication and experimental investigation of silicon micro heat pipes for cooling electronics
- Author
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Monique Lallemand, S Launay, M. Le Berre, Valérie Sartre, INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)
- Subjects
Materials science ,020209 energy ,Mechanical Engineering ,Enhanced heat transfer ,02 engineering and technology ,Heat sink ,021001 nanoscience & nanotechnology ,6. Clean water ,Electronic, Optical and Magnetic Materials ,[SPI]Engineering Sciences [physics] ,Heat pipe ,Thermal conductivity ,Mechanics of Materials ,Thermocouple ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Water cooling ,Wafer ,Electrical and Electronic Engineering ,Composite material ,0210 nano-technology ,Condenser (heat transfer) ,ComputingMilieux_MISCELLANEOUS - Abstract
An experimental investigation was conducted to determine the thermal behaviour of micro heat pipe (MHP) arrays micromachined in silicon wafers. Two types of MHP arrays were tested, one with triangular channels, 230 μm wide, 170 μm deep, and the other with triangular channels, 500 μm wide, 340 μm deep, coupled with arteries. Both types of arrays were fabricated using an anisotropic etching process. Once fabricated, a plain Si wafer was used to seal the pipe array hermetically. Two working fluids were tested, ethanol and methanol. A polysilicon heater was used to supply the heat input, and cooling water flowing through the condenser was used as a heat sink. Fill charges from 0% up to 66% were tested. The axial temperature variation along the length of the pipe was measured using T-type thermocouples connected to a data acquisition system. The effective thermal conductivity was evaluated using the experimental temperature profiles and 3D thermal modelling. The results show a maximum improvement of 300% in effective thermal conductivity at high heat flux, which demonstrates enhanced heat transfer in a prototype with liquid arteries.
- Published
- 2003
20. Sens de la verticalité et scoliose idiopathique de l’adolescent
- Author
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Cécile Donzé, Jean-François Catanzariti, C. Pradeau, V. Avinee, and M. Le Berre
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Neurology ,Physiology (medical) ,Neurology (clinical) ,General Medicine - Abstract
Introduction La scoliose idiopathique de l’adolescent (SIA) est une deformation tridimentionnelle du rachis, d’etiologie inconnue. Nous posons l’hypothese pathogenique suivante : la SIA s’accompagne d’une representation centrale erronee de la verticalite a l’origine d’une adaptation posturale du tronc dans les 3 plans de l’espace. Pour le verifier, nous avons debute une etude dont l’objectif est d’evaluer le sens de la verticalite dans la SIA, a la fois dans ses composantes top down et bottom up . Materiel et methodes Trois types de mesure ont ete realisees : – Verticale visuelle subjective (VVS) realisee en conditions visuelles statique et dynamique (stimulation optocinetique 40°/sec) chez 83 SIA versus 15 controles non scoliotiques ; – Verticale posturale subjective (VPS) chez 12 SIA ; – evaluation de l’image du tronc deforme par le Spinal Appareance Questionnaire (SAQ) chez 19 SIA versus 5 hypercyphoses thoraciques. Resultats Exactement 51,8 % des SIA ont une VVS anormale, surtout en condition visuelle dynamique versus 0 % dans le groupe controle. Les valeurs de VPS dans la SIA sont proches de celles trouvees chez les hemiplegiques pusher (exemple : tilt droit = 8,28°4,05). Les SIA avec une scoliose majeure ont un SAQ significativement deteriore par rapport aux hypercyphoses thoraciques. Discussion–conclusion Un sous-groupe de patients SIA presente une perturbation du sens de la verticalite. Cette anomalie peut etre secondaire a la deformation scoliotique mais peut egalement etre un facteur d’evolutivite de la SIA.
- Published
- 2015
21. Cinétique de la formation de structures localisées dans un oscillateur paramétrique optique
- Author
-
M. Le Berre, E. Ressayre, Paul Mandel, A. Tallet, Mustapha Tlidi, and L. Di Menza
- Subjects
Physics ,General Physics and Astronomy ,Humanities - Abstract
La formation de structures localisees intenses dans le profil transverse du faisceau signal transmis par un oscillateur parametrique degenere (DOPO), presente un regime transitoire de coalescence pendant lequel la taille des domaines correspondants a des solutions de signes opposes s'agrandit selon une loi de puissance t 1/3 .
- Published
- 2000
22. Beyond the Mean-Field Model of the Ring Cavity
- Author
-
D. Leduc, A. Tallet, M. Le Berre, S. Patrascu, and E. Ressayre
- Subjects
Diffraction ,General Mathematics ,Applied Mathematics ,Mode (statistics) ,Chaotic ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Geometry ,Ring (chemistry) ,Square (algebra) ,Mean field theory ,Quantum mechanics ,Path (graph theory) ,Limit (mathematics) ,Mathematics - Abstract
The ring cavity device with large diffraction path in the free-space of the cavity cannotbe described within the mean-field model. It is shown to generate a large variety of monoconicaland multiconical patterns with wave and/or Turing modes, for anonlinear medium either made of two-level atoms or with a χ (2) crystal.Even in the limit of a single-longitudinal mode operation, monoconical structures can be differentfrom those predicted by the mean-field model. For instance, chaotic localized structures with anatomic medium and square patterns with a DOPO are presented.
- Published
- 1999
23. Striped and circular domain walls in the DOPO
- Author
-
D. Leduc, E. Ressayre, M. Le Berre, and A. Tallet
- Subjects
Physics ,Diffraction ,Nonlinear system ,Range (particle radiation) ,Optics ,Amplitude ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,business.industry ,Domain (ring theory) ,business ,Signal ,Atomic and Molecular Physics, and Optics - Abstract
A family of circular and striped domain walls with oscillatory tails have been observed with the propagation model for the DOPO that is more general than the mean-field model. The same structures are observed with diffraction inside or outside the cell, showing that diffraction and nonlinearity may be decoupled. They result from the switching of the signal amplitude, from the positive to the negative solution. They are formed for positive and negative signal detunings of order unity, in a wide range of input pump amplitude. A second-order MacLaurin expansion mapping model is found to agree well with the propagation model.
- Published
- 1999
24. Thermo-resistance based micro-calorimeter for continuous chemical enthalpy measurements
- Author
-
Sébastien Méance, Laurent Malaquin, Yong Chen, Jean-Jacques Greffet, F. Bertholle, G. Velve Casquillas, M. Le Berre, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL), and Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec
- Subjects
Microfluidics ,Enthalpy ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Integrated circuit ,010402 general chemistry ,01 natural sciences ,law.invention ,[SPI]Engineering Sciences [physics] ,Neutralization ,PDMS ,law ,Micro-calorimetry ,Electrical and Electronic Engineering ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Chemistry ,Fluid mechanics ,Lab-on-a-chip ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Calorimeter ,Glucose ,Chemical engineering ,Reagent ,Glass ,0210 nano-technology ,Platinum - Abstract
International audience; We present a thermo-resistance based micro-calorimeter using a glass/platinum/PDMS prototyping technology which is more flexible than the existing silicon based technology for lab on a chip device integration. Resistance monitoring and fluid injection techniques are optimized in order to reduce thermal noises and improve the detection sensibility. We used neutralization acid-base reaction to evaluate the device capability in determination of both reagent concentration and reaction enthalpy. We also performed a glucose/glucose oxy-dase enzymatic reaction to illustrate the advantage of using PDMS device for the studies of aerobic reaction.
- Published
- 2008
25. Seasonal variation of thermoregulatory behaviour in the Hippopotamus (Hippopotamus amphibius)
- Author
-
M. Le Berre, Christian Noirard, R. Ramousse, and Jean-Paul Léna
- Subjects
biology ,Ecology ,Thermoregulation ,Seasonality ,biology.organism_classification ,medicine.disease ,Hippopotamus amphibius ,Behavioural thermoregulation ,Hippopotamidae ,Animal ecology ,biology.animal ,Hippopotamus ,Dry season ,medicine ,Animal Science and Zoology ,Ecology, Evolution, Behavior and Systematics - Abstract
The hippopotamus (Hippopotamus amphibius) spends more than 12 h a day in the water. Hippos are often submitted to water temperatures that vary with the seasons. We hypothesize that this difference between cool and warm water temperatures leads to variations in behavioural thermoregulation. We recorded the exposure of hippos to sunshine at the beginning and at the end of the dry season. Our results show that (1) sunshine exposure lasted much longer in cool water and (2) sun-bathing occurred during the hottest hours. It is therefore likely that in cool water hippos were cold and expressed an original behaviour of search for heat.
- Published
- 2007
26. Localized structures in chaotic patterns: From disorder to ordering
- Author
-
A. S. Patrascu, E. Ressayre, A. Tallet, and M. Le Berre
- Subjects
Physics ,Quantum mechanics ,Chaotic ,Atomic and Molecular Physics, and Optics - Published
- 1997
27. Thermal drift of piezoresistive properties of LPCVD polysilicon thin films between room temperature and 200 °C
- Author
-
M. Le Berre, D. Barbier, B. Semmache, P. Kleimann, INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)
- Subjects
010302 applied physics ,Materials science ,Silicon ,Mechanical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Chemical vapor deposition ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Piezoresistive effect ,Monocrystalline silicon ,chemistry ,Mechanics of Materials ,Electrical resistivity and conductivity ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,General Materials Science ,Grain boundary ,Composite material ,Thin film ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
Investigations of the thermal drifts of the resistivity and gauge factors of polysilicon are needed to extend its use as a transducing material for high temperature piezoresistive microsensor applications. Longitudinal gauge factors of LPCVD B-doped and rapid thermal-annealed polysilicon films, patterned onto oxidized silicon using a clamped beam technique, have been measured in the 20–200 °C temperature range as a function of the doping concentration between 8 × 10 18 and 10 20 cm −3 . The gauge factors have been simulated as a function of the B-concentration and the temperature, starting from experimental data for the polysilicon resistivity and literature data for the hole resistivity and the piezoresistive effect in monocrystalline silicon. Only a model involving a significant piezoresistive effect at grain boundaries can adequately fit the temperature dependent gauge factors of polysilicon.
- Published
- 1997
28. Micro-Raman study of thermoelastic stress distribution in oxidized silicon membranes and correlation with finite element modeling
- Author
-
M. Le Berre, Yannick Guyot, E. Bustarret, D. Barbier, Bernard Champagnon, C. Malhaire, A. Sibai, INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,Silicon ,Analytical chemistry ,Silicon on insulator ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,Stress (mechanics) ,[SPI]Engineering Sciences [physics] ,symbols.namesake ,Thermoelastic damping ,0103 physical sciences ,General Materials Science ,Composite material ,ComputingMilieux_MISCELLANEOUS ,[PHYS]Physics [physics] ,010302 applied physics ,Mechanical Engineering ,Biaxial tensile test ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Finite element method ,chemistry ,Mechanics of Materials ,symbols ,Profilometer ,0210 nano-technology ,Raman spectroscopy - Abstract
Silicon on insulator (SOI) pressure sensors show potential applications in high temperature environment. However, as a result of thermal mismatch, large stresses usually exist in the composite SiO 2 /Si membranes which would provide an otherwise promising substrate for such sensors. These stresses can significantly influence the long term reliability of such membranes. In this work a high spatial resolution (10 μm 2 ) Raman spectroscopy method has been used to measure the localized stresses over an oxidized membrane, thus yielding stress maps. The method is based on the frequency shift of the Raman line at 520 cm −1 . Shift between 0.05 and 1 cm −1 are observed. A three-dimensional commercially available finite element modeling (FEM) software (ANSYS) has been used to modelize the thermal stress distribution over the complete micromachined bilayer membrane. Its validity has been checked out through optical profilometer deflection measurements. The experimental Raman shifts were compared with those calculated using stresses from FEM and a biaxial stress hypothesis. Finally, the sensitivity of Raman stress mapping method for high temperature SOI pressure sensors is discussed.
- Published
- 1997
29. Fifth-order perturbation analysis for removing the degeneracy between squares and rhombuses
- Author
-
E. Ressayre, A. Tallet, M. Le Berre, and D. Leduc
- Subjects
Physics ,Third order ,Mathematical analysis ,Structure (category theory) ,Range (statistics) ,Order (ring theory) ,Rhombus ,Degeneracy (mathematics) ,Atomic and Molecular Physics, and Optics ,Energy (signal processing) ,Square (algebra) - Abstract
At the third order of the order parameter expansion, the system under study is variational, and for some range of parameters, a two-mode structure may occur. Both a square pattern and a 48\ifmmode^\circ\else\textdegree\fi{} rhombic pattern are shown to minimize the free energy, while the numerical simulations of the full equations display only the squares. The expansion at the nontrivial fifth order removes the degeneracy between the two different patterns and predicts squares.
- Published
- 1997
30. Geometric Friction Directs Cell Migration
- Author
-
Yong Chen, Matthieu Piel, Yan-Jun Liu, Paolo Maiuri, Olivier Bénichou, M. Le Berre, Raphaël Voituriez, Jie Hu, Le Berre, M, Liu, Yj, Hu, J, Maiuri, P, Benichou, O, Voituriez, R, Chen, Y, and Piel, M
- Subjects
Work (thermodynamics) ,Friction ,Ratchet ,FOS: Physical sciences ,General Physics and Astronomy ,Cell motion ,Condensed Matter - Soft Condensed Matter ,Models, Biological ,01 natural sciences ,03 medical and health sciences ,Optics ,Cell Movement ,Cell Behavior (q-bio.CB) ,0103 physical sciences ,Humans ,010306 general physics ,Brownian motion ,030304 developmental biology ,Physics ,0303 health sciences ,business.industry ,Isotropy ,Cell migration ,Adhesion ,Fibroblasts ,Classical mechanics ,FOS: Biological sciences ,Quantitative Biology - Cell Behavior ,Soft Condensed Matter (cond-mat.soft) ,Particle ,business - Abstract
In the absence of environmental cues, a migrating cell performs an isotropic random motion. Recently, the breaking of this isotropy has been observed when cells move in the presence of asymmetric adhesive patterns. However, up to now the mechanisms at work to direct cell migration in such environments remain unknown. Here, we show that a non-adhesive surface with asymmetric micro-geometry consisting of dense arrays of tilted micro-pillars can direct cell motion. Our analysis reveals that most features of cell trajectories, including the bias, can be reproduced by a simple model of active Brownian particle in a ratchet potential, which we suggest originates from a generic elastic interaction of the cell body with the environment. The observed guiding effect, independent of adhesion, is therefore robust and could be used to direct cell migration both in vitro and in vivo., Comment: To appear in PRL. Supplementary Information file available on request
- Published
- 2013
31. Bifurcations from a 8-fold orientational order quasipattern in a polarization instability device
- Author
-
M. Le Berre, E. Ressayre, D. Leduc, and A. Tallet
- Subjects
Physics ,business.industry ,Numerical analysis ,Nonlinear optics ,Rhombus ,Polarization (waves) ,Instability ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Quasiperiodic function ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Nonlinear Sciences::Pattern Formation and Solitons ,Refractive index ,Bifurcation - Abstract
The stability of the 8-fold orientational order quasipattern is studied both analytically and numerically. Close to the intensity threshold, the sequence, that minimizes the free energy, displays structures built up with four, two and one modes, successively, as the linear refractive index decreases. Differently, when increasing the intensity above the threshold, the 8-fold orientational order quasipattern bifurcates to a three mode quasiperiodic pattern, followed by a robust rhombic pattern. A multiconical emission process is invoked to explain the occurrence of the rhombuses.
- Published
- 1996
32. Daisy patterns in the passive ring cavity with diffusion effects
- Author
-
M. Le Berre, A.S. Patrascu, A. Tallet, and E. Ressayre
- Subjects
Optics ,Materials science ,business.industry ,Hexagonal crystal system ,Pattern formation ,Petal ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Diffusion (business) ,Ring (chemistry) ,business ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Abstract
Near-field patterns with three to fifteen petals set on a single circle are numerically observed in the ring cavity device. Three to six petal daisies result from usual finite size effects. We point out the non-trivial formation of seven to fifteen petal daisies, with a top-hat input, and a small diffusion term that controls this daisy-type pattern formation, preventing the usual hexagonal structure to be formed.
- Published
- 1996
33. Spatio-temporal sub-harmonic cascade in a non-linear interferometer with a liquid-crystal light valve
- Author
-
M Le Berre, S Aumaitre, E. Ressayre, and A. Tallet
- Subjects
Period-doubling bifurcation ,Physics ,Series (mathematics) ,business.industry ,General Engineering ,Geometry ,Atomic and Molecular Physics, and Optics ,Nonlinear system ,Interferometry ,Optics ,Cascade ,Bounded function ,Harmonic ,Spiral (railway) ,business - Abstract
A bounded spatio-temporal period-doubling sequence is shown to occur in the Ahkmanov et al. non-linear interferometer. This happens when the pattern is a rotating 2k-armed spiral. First, all arms are identical and the period is the time required for any arm to rotate by the angle 2 pi /2k. As the control parameter increases, the time trace at some location on the pattern displays period doubling as the arms develop progressively distinct spatial modulations. Period 2 behaviour occurs when the nearest patterns similar to arm 'i' are arms 'i+or-2', period 4 behaviour occurs when arm 'i' has arms 'i+or-4' as its nearest similar neighbours, and so on until period 2k when all arms are distinct and the pattern must complete a full revolution for the time series to repeat. Such a cascade is shown to be qualitatively modelled by a mapping.
- Published
- 1995
34. Simulation and analysis of the flower-like instability in the single-feedback mirror experiment with rubidium vapor
- Author
-
A. Maître, D. Leduc, A. Tallet, E. Ressayre, and M. Le Berre
- Subjects
Diffraction ,Physics ,Zeeman effect ,Aspect ratio ,business.industry ,chemistry.chemical_element ,Nonlinear optics ,Near and far field ,Instability ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Rubidium ,symbols.namesake ,Optics ,chemistry ,symbols ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Adiabatic process ,business - Abstract
Flower-like patterns are numerically investigated when the schematic Rb four-level relevant transition is reduced to the lower two Zeeman sub-levels via the adiabatic elimination of the upper states. These flower-like patterns are the signature of small aspect ratio while typical patterns like squares are displayed in the opposite limit. Depending on the relative weights of diffraction effects and nonlinearities, they display, or not, self-similar shapes in the near and the far field.
- Published
- 1995
35. A general method for tensor averaging and an application to polycrystalline materials
- Author
-
E. Belorizky, M. Le Berre, and W. Grieshaber
- Subjects
Physics ,Mathematical analysis ,General Chemistry ,engineering.material ,Condensed Matter Physics ,Piezoresistive effect ,Polycrystalline silicon ,Condensed Matter::Superconductivity ,Materials Chemistry ,engineering ,Symmetric tensor ,Crystallite ,Tensor ,Invariant (mathematics) ,Tensor density ,Physical quantity - Abstract
A general method is presented for determining the average tensorial components of a physical quantity for a polycrystalline sample with random crystallite orientation, when this tensor is known for a monocrystal. The technique, based on the determination of the rotationally invariant part of the tensor, is very convenient and provides analytical results. Explicit expressions are given for symmetrical 4th rank and 8th rank tensors and are applied to calculate piezoresistive effects in polycrystalline silicon.
- Published
- 1995
36. Why does a Ginzburg-Landau diffraction equation become a diffusion equation in the passive ring cavity?
- Author
-
A. Tallet, M Le Berre, and E. Ressayre
- Subjects
Physics ,Ring (mathematics) ,Diffusion equation ,Condensed matter physics ,General Engineering ,Ginzburg landau equation ,Physics::Optics ,Nonlinear optics ,Atomic and Molecular Physics, and Optics ,Kirchhoff's diffraction formula ,Optical bistability ,Hysteresis ,Condensed Matter::Superconductivity ,Quantum mechanics ,Nonlinear Sciences::Pattern Formation and Solitons ,Ginzburg landau - Abstract
The Swift-Hohenberg diffusion-type equation is shown to be the normal form of the purely diffraction-type Ginzburg-Landau equation for the passive and saturable ring cavity in the vicinity of nascent hysteresis.
- Published
- 1995
37. Electrical and structural properties of rapid thermally annealed boron‐doped silicon films deposited by plasma‐enhanced chemical‐vapor deposition
- Author
-
M. Le Berre, V. Conedera, J. Sicart, Jean-Louis Robert, P. Pinard, P. Jeanjean, Etienne Bustarret, Mustapha Lemiti, J. Cali, W. Grieshaber, and P. Sellitto
- Subjects
inorganic chemicals ,Materials science ,Silicon ,Annealing (metallurgy) ,Doping ,technology, industry, and agriculture ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Chemical vapor deposition ,Piezoresistive effect ,chemistry ,Plasma-enhanced chemical vapor deposition ,Thin film ,Composite material ,Boron - Abstract
The structural, electrical, and piezoresistive properties of in situ boron‐doped thin silicon layers deposited by plasma‐enhanced chemical‐vapor deposition at 320 °C on oxidized silicon substrates and subjected to a rapid thermal anneal (1100 °C for 20 s) have been investigated. Macroscopic electrical parameters derived from resistivity and Hall‐effect measurements were compared to microscopic characteristics deduced from optical data to explain the low‐temperature coefficients of resistance measured on this polycrystalline material. Finally, the piezoresistivity gauge factors of these heavily doped layers are discussed in view of their internal stress state and of other structural characteristics.
- Published
- 1994
38. Rotating spiral waves in a nonlinear optical system with spatial interactions
- Author
-
M. Le Berre, E. Ressayre, A. Tallet, and N.I. Zheleznykh
- Subjects
Physics ,Nonlinear optical ,Classical mechanics ,General Mathematics ,Applied Mathematics ,Dispersion relation ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Curvature ,Rotation ,Spiral ,Eigenvalues and eigenvectors - Abstract
The formation of multi-petals and multi-spirals is analysed with the help of a generalized dispersion relation, taking advantage of the invariance of the rotation frequency of a pattern. It results in an eigenvalue problem, which allows us to predict the rotation frequency and the radial curvature of the pattern, in good agreement with exact calculations: A stationary pattern is predicted to look like petals, while a uniform rotating pattern is predicted to have some curvature, leading to a spiral shape.
- Published
- 1994
39. Spatial patterns in a passive ring cavity with atoms
- Author
-
E. Ressayre, A. Tallet, A.S. Patrascu, M. Le Berre, and N.I. Zheleznykh
- Subjects
Boundary effects ,General Mathematics ,Applied Mathematics ,Chaotic ,Structure (category theory) ,General Physics and Astronomy ,Statistical and Nonlinear Physics ,Geometry ,Ring (chemistry) ,Pattern selection ,Spatial ecology ,Radiative transfer ,Boundary value problem ,Mathematics - Abstract
We present numerical simulations of a simplified model for the ring cavity device in the case of round-trip time equal to the atomic radiative lifetime. Real pattern effects are of primordial importance, especially in small systems where the boundary conditions seem the key for the pattern selection. For a plane-wave input, our system displays not only hexagons, as in the mean-field model, but also stationary rolls, squares and octagons with a weakly chaotic structure. All these structures are also obtained in the case of bell-shaped input profile with large aspect ratio; they even appear regular and wonderful, as if boundary effects stabilize them.
- Published
- 1994
40. Climbing abilities in four species of desert rodents
- Author
-
L. Le Guelte and M. Le Berre
- Subjects
biology ,Ecology ,Gerbillus pyramidum ,Climbing ,Acomys cahirinus ,Animal Science and Zoology ,biology.organism_classification ,Gerbillus ,Ecology, Evolution, Behavior and Systematics - Abstract
The potential locomotor performances of four Saharan species of rodents were tested in laboratory conditions, using three experimental situations. Two questions were investigated: Is each of these species able to use the vertical dimension when it is available? Does each of these species behave efficiently in a new environment? We tested the performances of Acomys cahirinus (Desmarest 1819) and Gerbillus campestris (Le Vaillant 1867) that are found in rocky environments in the wild and of Gerbillus pyramidum (I. Geoffroy 1825) and Meriones shaivi (Rozet 1833), that are found in sandy environments. Climbing performance of the species was tested on a horizontal platform, a thread and a tree-branch. From our data, we concluded that Acomys and G. campestris showed an efficient behaviour in these three tasks. M. shawi and to a lesser extent G. pyramidum were unable to behave efficiently in the test situations.
- Published
- 1993
41. Microstructural and magnetic properties of thick (≥10μm) magnetron sputtered barium ferrite films
- Author
-
J.P. Chatelon, Bruno Canut, D. Givord, M. Le Berre, A.-S. Dehlinger, S. Perrot, David Albertini, Jean Jacques Rousseau, Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), INL - Spectroscopies et Nanomatériaux (INL - S&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), INL - Plateforme Technologique Nanolyon (INL - Nanolyon), Station Nationale d’Essais de Semences (SNES), Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Micro et NanoMagnétisme (MNM), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)
- Subjects
010302 applied physics ,Materials science ,Analytical chemistry ,02 engineering and technology ,Sputter deposition ,Coercivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Rutherford backscattering spectrometry ,Microstructure ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,Nuclear magnetic resonance ,chemistry ,Sputtering ,0103 physical sciences ,Cavity magnetron ,Deposition (phase transition) ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,0210 nano-technology ,Barium ferrite ,ComputingMilieux_MISCELLANEOUS - Abstract
This work focuses on the properties of 10–15 μm thick barium M-type hexaferrite (BaFe 12 O 19 or BaM) films deposited by non-reactive RF magnetron sputtering on alumina substrates. High deposition rates were achieved through deposition at room temperature and operation at an RF power of 100 W. By varying sputtering gas pressure, the dc magnetic properties were correlated with structural, morphological and compositional properties obtained by X-ray diffraction (XRD), atomic force microscopy (AFM) and Rutherford backscattering spectrometry (RBS), respectively. A deposition pressure of P =3 Pa enables one to reach the best compromise between high deposition rate (0.75 μm/h) and adequate crystallographic, stoichiometric and magnetostatic properties. Finally the gyromagnetic properties at high frequency were assessed through the characterization of coplanar isolator up to 60 GHz. As such, hexaferrite films prepared using this technique may offer opportunities for the next generation of self-biased planar microwave devices.
- Published
- 2010
42. Coplanar waveguides with or without barium ferrite thin films
- Author
-
Beatrice Payet-Gervy, Francis Calmon, M. Le Berre, Tao Zhou, Evangéline Bènevent, A.-S. Dehlinger, E. Verney, S. Perrot, INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), Laboratoire Telecom Claude Chappe (LT2C), Université Jean Monnet [Saint-Étienne] (UJM)-Ecole d'ingenieurs Telecom Saint Etienne, and Radiall
- Subjects
Materials science ,02 engineering and technology ,7. Clean energy ,01 natural sciences ,010309 optics ,chemistry.chemical_compound ,Condensed Matter::Materials Science ,Condensed Matter::Superconductivity ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Thin film ,Barium ferrite ,business.industry ,Electrical engineering ,020206 networking & telecommunications ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,[SPI.ELEC]Engineering Sciences [physics]/Electromagnetism ,chemistry ,Remanence ,Ferrite thin films ,Optoelectronics ,Ferrite (magnet) ,business ,Microwave - Abstract
The attractive properties of coplanar waveguides with or without ferrite thin films are presented in this article.The microwave characteristics are measured from 1 to 55 GHz. Also, analytical calculations and simulations are performed. The influence of ferrite thin film with remanent magnetization in-plane or out-of-plane is studied. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2007–2010, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25393
- Published
- 2010
43. YIG Thin Film Used to Miniaturize a Coplanar Junction Circulator
- Author
-
J. J. Rousseau, D. Givord, B. Sauviac, O. Zahwe, M. F. Blanc Mignon, B. Abdel Samad, J. P. Chatelon, M. Le Berre, Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), Laboratoire de physique de la matière (LPM), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Micro et NanoMagnétisme (MNM), Institut Néel (NEEL), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
- Subjects
Materials science ,Circulator ,Yttrium iron garnet ,General Physics and Astronomy ,02 engineering and technology ,RX ,01 natural sciences ,chemistry.chemical_compound ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Miniaturization ,Electrical and Electronic Engineering ,Thin film ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,010302 applied physics ,business.industry ,RF passive components ,020206 networking & telecommunications ,Sputter deposition ,Electronic, Optical and Magnetic Materials ,chemistry ,visual_art ,Electronic component ,visual_art.visual_art_medium ,Optoelectronics ,Ferrite (magnet) ,Microwave range ,business - Abstract
International audience; The preparation of Yttrium Iron Garnet films (YIG) presenting controlled magnetic properties is of great interest for miniaturization of RF passive components. The present work deals with the integration of YIG ferrite sputtered films for coplanar circulators. These components must work at frequencies above 10GHz, and they must be compatible with mass-production and low-cost process. The YIG films (of thickness 15 μm) are deposited on an alumina substrate by RF magnetron sputtering. Their structural mechanical and magnetic properties in the millimetre wave range are optimised to enable the film's integration. A circulator is fabricated using such prepared film, and its properties in the microwave range are characterised using a network analyzer and a probing system.
- Published
- 2010
44. Multi-conical instability in the passive ring cavity: linear analysis
- Author
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A. S. Patrascu, C. Nath, M. Le Berre, Andree Tallet, and Elisabeth Ressayre
- Subjects
Materials science ,business.industry ,Buffer gas ,Conical surface ,Linear analysis ,Ring (chemistry) ,Instability ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Optics ,Maxwell's equations ,Physics::Atomic and Molecular Clusters ,symbols ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,business ,Conical shell - Abstract
The instability threshold characteristics are derived for the ring cavity with passive weakly absorbing two-level atoms cell. Emission of several conical shells is predicted, depending on the optical arrangement, and on the buffer gas pressure. In the case of pure vapor, each conical shell has its own frequency, while all the conical shells display the same frequency in case of large buffer gas pressure.
- Published
- 1992
45. Wave-breaking and generic singularities of nonlinear hyperbolic equations
- Author
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M. Le Berre, Stephan T. Grilli, Philippe Guyenne, and Y. Pomeau
- Subjects
Physics ,Differential equation ,Applied Mathematics ,Mathematical analysis ,Fluid Dynamics (physics.flu-dyn) ,General Physics and Astronomy ,Breaking wave ,FOS: Physical sciences ,Statistical and Nonlinear Physics ,Physics - Fluid Dynamics ,01 natural sciences ,Power law ,010305 fluids & plasmas ,Power (physics) ,Nonlinear system ,0103 physical sciences ,Gravitational singularity ,010306 general physics ,Focus (optics) ,Hyperbolic partial differential equation ,Mathematical Physics - Abstract
Wave-breaking is studied analytically first and the results are compared with accurate numerical simulations of 3D wave-breaking. We focus on the time dependence of various quantities becoming singular at the onset of breaking. The power laws derived from general arguments and the singular behavior of solutions of nonlinear hyperbolic differential equations are in excellent agreement with the numerical results. This shows the power of the analysis by methods using generic concepts of nonlinear science.
- Published
- 2008
- Full Text
- View/download PDF
46. Development of millimeter wave integrated circulator based on barium ferrite
- Author
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M. Le Berre, Didier Vincent, H. Hassane, Dominique Givord, V. Larrey, A.-S. Dehlinger, E. Benevent, Micro et NanoMagnétisme (MNM), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), DIOM (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), Radiall, Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), INL - Dispositifs Electroniques (INL - DE), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL)
- Subjects
Materials science ,Circulator ,Barium ferrites ,Bioengineering ,02 engineering and technology ,Biomaterials ,chemistry.chemical_compound ,Sputtered film ,Integrated circulator ,Magnetic oxide ,0202 electrical engineering, electronic engineering, information engineering ,Barium ferrite ,business.industry ,Millimeter wave ,020206 networking & telecommunications ,021001 nanoscience & nanotechnology ,Telecommunications network ,Power (physics) ,chemistry ,Mechanics of Materials ,Extremely high frequency ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Optoelectronics ,Millimeter ,Antenna (radio) ,0210 nano-technology ,business ,Microwave - Abstract
International audience; The development of telecommunications networks requires low-cost microwave and millimeter waves integrated devices. Among the microwave devices based on the non-reciprocity of ferrites, circulators are the most important. A typical use of circulators is in communication equipment (mobile phone and low power radar detection). Their operation allows to combine emission and detection using the same antenna. This work concerns the characterization of barium hexaferrite sputtered films and the device integration for the development of an integrated circulator working at a frequency of 40 GHz.
- Published
- 2008
47. Threshold and large amplitude self-oscillations in a saturable Rayleigh-gain ring cavity
- Author
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E. Ressayre, A. Tallet, and M. Le Berre
- Subjects
Physics ,business.industry ,Physics::Optics ,Nonlinear optics ,Condensed Matter Physics ,Ring (chemistry) ,Atomic and Molecular Physics, and Optics ,law.invention ,Optical bistability ,symbols.namesake ,Optics ,Amplitude ,law ,Optical cavity ,symbols ,Physics::Accelerator Physics ,Physics::Atomic Physics ,Electrical and Electronic Engineering ,Atomic physics ,Rayleigh scattering ,business ,Refractive index ,Beam (structure) - Abstract
Periodic instabilities which occur in the output beam of a ring cavity containing a short cell of passive homogeneously broadened two-level atoms are studied as a function of the atomic detuning and the mode spacing in a high-finesse cavity. The output characteristics are found to be very sensitive to the round-trip time of the light through the cavity and to the refractive index. Conditions for the occurrence of large-amplitude self-oscillation are given in terms of these two parameters. >
- Published
- 1990
48. Fish genotype significantly influences susceptibility of juvenile rainbow trout, Oncorhynchus mykiss (Walbaum), to waterborne infection with infectious salmon anaemia virus
- Author
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Stéphane Biacchesi, S. Le Guillou, Edwige Quillet, Pierre Boudinot, Abdenour Benmansour, Michel Brémont, M Le Berre, Unité de recherche Virologie et Immunologie Moléculaires (VIM (UR 0892)), Institut National de la Recherche Agronomique (INRA), Unité de recherche Génétique des Poissons (UGP), and ProdInra, Migration
- Subjects
Time Factors ,GENETIC SUSCEPTIBILITY ,Genotype ,Veterinary (miscellaneous) ,[SDV]Life Sciences [q-bio] ,Isavirus ,Zoology ,Aquatic Science ,Biology ,03 medical and health sciences ,Fish Diseases ,Orthomyxoviridae Infections ,RAINBOW TROUT ,Genetic predisposition ,Juvenile ,Animals ,Genetic Predisposition to Disease ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,04 agricultural and veterinary sciences ,[SDV] Life Sciences [q-bio] ,Fishery ,INFECTIOUS SALMON ANAEMIA VIRUS ,WATERBORNE INFECTION ,Infectious salmon anaemia virus ,Oncorhynchus mykiss ,040102 fisheries ,0401 agriculture, forestry, and fisheries ,%22">Fish ,Rainbow trout ,Water Microbiology - Abstract
International audience
- Published
- 2007
49. Feasibility of an integrated self biased coplanar isolator with barium ferrite films
- Author
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J.P. Chatelon, S. Capraro, M. Le Berre, J. J. Rousseau, Bernard Bayard, T. Rouiller, D. Barbier, Dispositifs et Instrumentation en Optoélectronique et micro-ondes (DIOM), Université Jean Monnet [Saint-Étienne] (UJM), INL - Dispositifs Electroniques (INL - DE), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Materials science ,business.industry ,Isolator ,Electrical engineering ,020206 networking & telecommunications ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Magnetization ,Magnetic anisotropy ,chemistry ,Remanence ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,Ferrite (magnet) ,Electrical and Electronic Engineering ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,0210 nano-technology ,business ,Saturation (magnetic) ,Barium ferrite ,Microwave ,ComputingMilieux_MISCELLANEOUS - Abstract
The development of passive devices using a ferrite is a major focus of current research for electronic applications in the microwave range (circulators and isolators). Hexagonal ferrite, such as barium ferrite (BaFe12O19 or BaM), which has a large resistivity and high permeability at high frequencies are indeed of great interest for microwave device applications. In this work we developed an integrated and self-biased coplanar isolator using BaM sputtered films. BaM films, 1-36 mum thick, were deposited under optimized conditions by radio frequency magnetron sputtering on alumina substrates. The films were crystallized using a 800degC thermal annealing. Isolators were then realized using patterning of coplanar waveguides (CPW) with standard lift-off technique. The slots and the central width were 300 mum wide and gold was used for the conductor lines. We evaluated the influence of various parameters on the device performances: the magnetic film's thickness, the positioning of the magnetic film (CPW deposited onto the magnetic film or directly on the substrate), the CPW metallic thickness and the polarizing field. As standard design, the CPW were deposited on the top of the magnetic film. At the remanent magnetization (no polarizing field applied), the transmission coefficients then showed a non reciprocal effect, which reached 5.4 dB per cm of line length at 50 GHz for a 26.5 mum thick BaM film. Both the insertion losses and the non-reciprocal effect measured increased with the magnetic film thickness with a saturation effect. In the second design where the CPW is deposited directly on the substrate after a selective etching of the BaM film, we measured that the non reciprocal effect reached higher values for lower BaM thicknesses than for the first design and that the insertion losses also decreased. The interaction between the field lines created by the conductors and the magnetic film was indeed favored in the second case. Finally, we show the tunability of the isolator with the polarizing field.
- Published
- 2007
50. Liquid Handling in a Microfluidic Chip by Micro-Aspiration
- Author
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G.V. Casquillas, M. Le Berre, C. Crozatier, and Yong Chen
- Subjects
Materials science ,Microfluidic chip ,Multilayer soft lithography ,Pressure control ,Microfluidics ,Nanotechnology ,Protein crystallization ,Soft lithography - Abstract
We report on a new method to handle fluids in microfluidic systems by using both micro- aspiration and PDMS valves. Multilayer soft lithography technique has been used to fabricate microfluidic circuit and micro-aspiration network. We introduced micro-aspiration areas to locally create vacuum in the microfluidic network. The induced pressure differences can drive confined liquid into motion. This allowed us to fill chambers, form droplets and displace droplets in channels without any other external injection apparatus. We describe the principle and the operation of this method. Finally, we discuss a possible application of this method in the field of protein crystallization.
- Published
- 2007
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