Cette recherche est soutenue par la US Defense Advanced Research Projects Agency en vertu de centres intégrés de recherche en photonique Ingénierie (Cipher) programme avec le Dr J. Scott Rodgers comme chef de projet. L&#39;information fournie dans ce rapport ne reflètent pas nécessairement la position ou la politique du gouvernement américain et aucune approbation officielle doit être déduite.

1. Préparation de microsphères PDMS (Sphère I) <ol><li> Polydiméthylsiloxane (PDMS) de base et le durcisseur sont mélangés avec un rapport en volume de 60:1. </li><li> Un brin de fibre optique en silice, environ 2 cm de long, est d&#39;abord dépouillé de sa gaine plastique à l&#39;aide d&#39;un décapant optique. </li><li> Une extrémité de la fibre est chauffée et étirée pour former une extrémité de tige qui est ~ 25-50 pm de diamètre à la pointe. </li><li> L&#39;extrémité étirée de la fibre est immergée dans le mélange de PDMS par une longueur d&#39;environ 2-4 mm, puis est retiré. </li><li> La tension superficielle et le poids du mélange PDMS permettre la formation d&#39;une sphère à l&#39;extrémité de la fibre en silice. La taille de la sphère est commandée par la longueur de trempage et la vitesse d&#39;extraction. En faisant varier ces deux paramètres, le diamètre des sphères dans la gamme de 100 um - 1000 um peut être obtenue. </li><li> L&#39;ensemble de microsphères / tige est ensuite placé dans une étuve à ~ 90 ° C pendant 4 heures pour permettre un durcissement correct de la polymatériel mer (pour former des chaînes réticulées). Figure 1a est une vue schématique d&#39;I. Sphère </li></ol> 2. Préparation à base de PDMS Triple Sphere Layer (Sphère II) <ol><li> Microsphère 60:1 PDMS est utilisé en tant que noyau intérieur. Les mêmes étapes décrites en 1) ci-dessus est suivi de ce processus. </li><li> Un mélange de titanate de baryum (BaTiO 3) nano-particules et 60:1 PDMS est utilisé comme couche intermédiaire. Le mélange PDMS, préparé de la manière décrite à 1,1) ci-dessus, on mélange avec du titanate de baryum nano-particules. </li><li> Le noyau microsphère PDMS décrit dans 2,1) est ensuite plongée dans le mélange de titanate de baryum-PDMS pour la couche (avec une épaisseur de couche nominale de ~ 10 um). </li><li> Ensuite, la sphère à deux couches est placé dans une étuve à ~ 90 ° C pendant 4 heures pour permettre la polymérisation convenable de la deuxième couche. </li><li> Une fois la sphère à deux couches est durcie, elle est de nouveau plongé dans un mélange de PDMS 60:1 à fournir un revêtement extérieur (troisième couche). Ce externecouche sert de guide optique sphérique (épaisseur ~ um 10). Figure 1b est une vue schématique de Sphère II. </li></ol> 3. Silice / Préparation de microsphères PDMS (Sphère III) <ol><li> Une section ~ 3 cm de long d&#39;une fibre optique unique mode de silice est d&#39;abord dépouillé de son tampon (plastique) de revêtement, puis son extrémité est fondu à l&#39;aide d&#39;un micro-torche (avec le revêtement et le noyau). La tension de surface et la gravité travailler ensemble pour façonner l&#39;extrémité fondue dans une sphère. Sphères ayant des diamètres allant de 200 à 500 um peut être obtenue par ce procédé. </li><li> La microsphère de silice est ensuite immergé dans un bain de PDMS de base (sans durcisseur), à la recouvrir d&#39;une couche de ~ 50 um. Cette couche extérieure reste aussi un très visqueux Bingham (limite d&#39;élasticité) de liquide. Figure 1c est une vue schématique de Sphère III. </li></ol> 4. Préparation de la fibre optique <ol><li> Une section d&#39;une fibre optique monomode est dépouillé de son cla plastiquedding l&#39;aide d&#39;un extracteur optique. À l&#39;aide d&#39;un micro-chalumeau la section rayée de la fibre est chauffé jusqu&#39;à ce qu&#39;il soit fondu (à la fois la gaine et coeur de la fibre). </li><li> Tandis que la partie centrale est en fusion, une extrémité de la fibre optique est tirée le long de son axe pour former une section conique de la fibre qui est à environ 1 cm de long. La durée du chauffage, la vitesse de tirage et de la distance déterminer le diamètre de la section conique qui se situe entre 10 et 20 um. La lumière provenant du laser DFB est couplée dans la sphère à travers la section conique de la fibre. Figure 2 montre le couplage fibre-sphère. </li></ol> 5. Optoélectronique Setup <ol><li> La sortie d&#39;un laser DFB accordable est couplé dans une fibre optique monomode à une extrémité et se terminant à une photodiode rapide sur l&#39;autre extrémité comme représenté sur la figure 3. </li><li> La sortie de la photodiode est numérisé à l&#39;aide d&#39;un convertisseur analogique-numérique (A / N) et stockées sur un ordinateur personnel (PC). </li><li&gt; L&#39;aide d&#39;une étape de micro-traduction de la microsphère (type I, II ou III) est mise en contact avec la partie conique de la fibre optique (figures 2 et 3) pour fournir un couplage optique entre les deux éléments. </li><li> Le laser DFB est réglée par un dispositif de commande laser. Le dispositif de commande laser, à son tour, est entraîné par un générateur de fonction qui fournit une entrée de tension en dents de scie. </li></ol> 6. Génération du champ électrique <ol><li> Deux plaques de laiton carrés (2 x 2 cm) d&#39;épaisseur de 1 mm sont utilisées pour générer le champ électrique uniforme. Les plaques sont reliées à une alimentation en tension et les capteurs sont placés dans la sphère de l&#39;écart entre les deux plaques (figure 4). </li><li> Afin d&#39;augmenter la sensibilité de la mesure, les sphères sont d&#39;abord polarisée dans un champ électrique de 1 MV / m pendant 2 heures. </li></ol>

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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermooptical+switches+using+coated+microsphere+resonators.">Thermooptical switches using coated microsphere resonators.</a> IEEE photonics technology letters. 14 (8), 1118-1120 (2002).</li><li>Little, B. E., Chu, S. T., Haus, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microring+resonator+channel+dropping+filters.">Microring resonator channel dropping filters.</a> Journal of lightwave technology. 15, 998-1000 (1997).</li><li>Offrein, B. J., Germann, R., Horst, F., Salemink, H. W. M., Beyerl, R., Bona, G. 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S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strain+tunable+high-Q+optical+microsphere+resonator.">Strain tunable high-Q optical microsphere resonator.</a> Optics communications. 145, 86-90 (1998).</li><li>Arnold, S., Khoshsima, M., Teraoka, I., Holler, S., Vollmer, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shift+of+whispering-gallery+modes+in+microspheres+by+protein+adsorption.">Shift of whispering-gallery modes in microspheres by protein adsorption.</a> Optics. 28 (4), 272-274 (2003).</li><li>Rosenberger, A. T., Rezac, J. 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V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure+tuning+of+whispering+gallery+mode+resonators.">Pressure tuning of whispering gallery mode resonators.</a> Journal of optical society of America B. 24 (10), 2721-2726 (2007).</li><li>Ioppolo, T., &#214;t&#252;gen, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+acceleration+on+the+morphology+dependent+optical+resonances+of+spherical+resonators.">Effect of acceleration on the morphology dependent optical resonances of spherical resonators.</a> Journal of optical society of America B. 28, 225-227 (2011).</li><li>Ayaz, U. K., Ioppolo, T., &#214;t&#252;gen, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wall+shear+stress+sensor+based+on+the+optical+resonances+of+dielectric+microspheres.">Wall shear stress sensor based on the optical resonances of dielectric microspheres.</a> Measurement science and technology. 22, 075203 (2011).</li><li>Ioppolo, T., Ayaz, U. K., &#214;t&#252;gen, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+of+whispering+gallery+modes+of+spherical+resonators+using+an+external+electric+field.">Tuning of whispering gallery modes of spherical resonators using an external electric field.</a> Optics express. 17 (19), 16465-16479 (2009).</li><li>Ioppolo, T., Stubblefield, J., &#214;t&#252;gen, M. 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Nous n&#39;avons rien à déclarer.

Les sphères sont d&#39;abord polarisé en reliant les électrodes à une alimentation en courant continu à haute tension. À la fin de la durée de polarisation, les conducteurs d&#39;électrodes sont déconnectées de l&#39;alimentation en courant continu et connecté à un générateur de fonction, comme indiqué dans la figure 4. Les résultats présentés dans les figures 5 à 8 montrent que positifs et négatifs des champs électriques (par rapport à la direction de polarisation...

<table border="1"><tbody><tr><td></td><td> Entreprise </td><td> Numéro de catalogue </td><td> Commentaires (optionnel) </td></tr><tr><td> PDMS </td><td> Dow Corning </td><td> Sylgard 184 </td><td></td></tr><tr><td> Fibre de silice </td><td> Les ventes d&#39;instruments en fibre </td><td> E-37AP15-FIS </td><td></td></tr><tr><td> Le titanate de baryum (BaTiO 3) des nanoparticules </td><td> Sigma Aldrich </td><td> 467634-100G </td><td></td></tr><tr><td> Laser Controller </td><td> ILX Lightwave </td><td> LDC-3724B </td><td></td></tr><tr><td> Laser DFB </td><td> Agere </td><td> Agere 2300 </td><td> 1,310 um longueur d&#39;onde centrale </td></tr><tr><td> Photodiode </td><td> Thorlabs </td><td> PDA10CS </td><td></td></tr><tr><td> Une carte / D </td><td> National Instruments </td><td> PXI 6115 </td><td></td>
 </tr>
 </tbody>
</table>

development of whispering gallery mode polymeric micro-optical electric field sensors

Modes optiques diélectriques micro-cavités ont reçu une attention considérable ces dernières années pour leur potentiel dans une large gamme d&#39;applications. Les modes optiques sont souvent appelées &quot;modes de galerie (WGM») ou «résonances morphologie charge» (MDR) et présentent des facteurs élevés de qualité optique. Certaines applications proposées de micro-cavités des résonateurs optiques sont en spectroscopie 1, la technologie laser micro-cavité 2, communications optiques 6.3 ainsi que la technologie des capteurs. Les applications de capteurs à base de WGM comprennent ceux de la biologie 7, la détection de traces de gaz 8, et la détection d&#39;impuretés dans les liquides 9. Capteurs mécaniques basés sur des résonateurs microsphères ont également été proposées, y compris ceux pour la force de 10,11, la pression 12, 13 et accélération paroi contrainte de cisaillement 14. Dans le présent, nous démontrons un capteur de WGM basée champ électrique, qui s&#39;appuie sur notre studi précédentees 15,16. Une application de ce capteur candidat est dans la détection de potentiel d&#39;action neuronale. Le capteur de champ électrique est basé sur des microsphères polymères multicouche diélectrique. Le champ électrique externe induit surface du corps et les forces sur les sphères (effet électrostrictif) conduisant à une déformation élastique. Ce changement dans la morphologie des sphères, conduit à des changements dans le WGM. Le champ électrique induit des changements WGM sont interrogés par l&#39;excitation des modes optiques des sphères de lumière laser. La lumière à partir d&#39;une rétroaction répartie (DFB) laser (longueur d&#39;onde nominale de ~ 1,3 um) est couplé côté-dans les microsphères à l&#39;aide d&#39;une section conique d&#39;une fibre optique monomode. Le matériau de base de la sphère est le polydiméthylsiloxane (PDMS). Trois géométries microsphères sont utilisées: (1) PDMS sphère avec un rapport volumétrique de 60:1 base-durcisseur mélange d&#39;agents, (2) à plusieurs couches avec sphère 60:1 PDMS noyau, afin d&#39;augmenter la constante diélectrique du ièmee sphère, une couche médiane de 60:1 PDMS qui est mélangé avec des quantités variables (2% à 10% en volume) de titanate de baryum et une couche externe de 60:1 PDMS et (3) la sphère de silice solide revêtu d&#39;une couche mince de PDMS de base non durci. Dans chaque type de capteur, la lumière laser à partir de la fibre conique est couplée dans la couche la plus externe qui fournit une grande qualité optique facteur WGM (Q ~ 10 6). Les microsphères sont polarisées pendant plusieurs heures à des champs électriques de ~ 1 MV / m pour accroître leur sensibilité au champ électrique.

Un mode optique (WGM) de la sphère est excité par la lumière laser lorsque la longueur du chemin optique parcouru par la lumière est un multiple entier de la longueur d&#39;onde laser. Pour le dispositif représenté sur la figure 3, la longueur du chemin optique est 2πrn, où n et r sont l&#39;indice de réfraction et le rayon de la sphère, respectivement. Utilisant géométrique rapprochement optique, une condition WGM est satisfaite lorsque 2πrn = lλ où <e...

Watch this Scientific Journal Video about Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors at JoVE.com

Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors

Un capteur de haute sensibilité photonique micro est développé pour la détection du champ électrique. Le capteur exploite les modes optiques d&#39;une sphère diélectrique. Les changements dans l&#39;perturbent champ électrique externe de la morphologie sphère conduit à des changements dans ses modes optiques. L&#39;intensité du champ électrique est mesurée par la surveillance de ces changements optiques.

Développement de Whispering Gallery mode polymères micro-capteurs de champ électrique

Optical modes of dielectric micro-cavities have received significant attention in recent years for their potential in a broad range of applications. The ...

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13.0K vues.  Southern Methodist University. Un capteur de haute sensibilité photonique micro est développé pour la détection du champ électrique. Le capteur exploite les modes optiques d'une sphère diélectrique. Les changements dans l'perturbent champ électrique externe de la morphologie sphère conduit à des changements dans ses modes optiques. L'intensité du champ électrique est mesurée par la surveillance de ces changements optiques.

Vidéo: Development of Whispering Gallery Mode Polymeric Micro-optical Electric Field Sensors

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

The customized techniques developed in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators are presented. The protocols to obtain and characterize these resonators are detailed, and an explanation of some of their applications in microwave photonics is given.

Les systèmes photoniques à micro-ondes Basé sur des résonateurs-galerie-mode de chuchotement

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various ...

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Ingénierie

Real-Time DC-dynamic Biasing Method for Switching Time Improvement in Severely Underdamped Fringing-field Electrostatic MEMS Actuators

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input bias voltage. However, the tradeoff for the improved switching performance is a relatively long settling time to reach each gap height in response to various applied voltages. Transient applied bias waveforms are employed to facilitate reduced switching times for electrostatic fringing-field MEMS actuators with high mechanical quality factors. Removing the underlying substrate of the fringing-field actuator creates the low mechanical damping environment necessary to effectively test the concept. The removal of the underlying substrate also a has substantial improvement on the reliability performance of the device in regards to failure due to stiction. Although DC-dynamic biasing is useful in improving settling time, the required slew rates for typical MEMS devices may place aggressive requirements on the charge pumps for fully-integrated on-chip designs. Additionally, there may be challenges integrating the substrate removal step into the back-end-of-line commercial CMOS processing steps. Experimental validation of fabricated actuators demonstrates an improvement of 50x in switching time when compared to conventional step biasing results. Compared to theoretical calculations, the experimental results are in good agreement.

The robust device design of fringing-field electrostatic MEMS actuators results in inherently low squeeze-film damping conditions and long settling times when performing switching operations using conventional step biasing. Real-time switching time improvement with DC-dynamic waveforms reduces the settling time of fringing-field MEMS actuators when transitioning between up-to-down and down-to-up states.

Real-Time DC-dynamique Méthode de sollicitation pour Temps de commutation amélioration de franges champ gravement sous-amorti électrostatiques MEMS Actionneurs

Mechanically underdamped electrostatic fringing-field MEMS actuators are well known for their fast switching operation in response to a unit step input ...

Characterization of Anisotropic Leaky Mode Modulators for Holovideo

Holovideo displays are based on light-bending spatial light modulators. One such spatial light modulator is the anisotropic leaky mode modulator. This modulator is particularly well suited for holographic video experimentation as it is relatively simple and inexpensive to fabricate1-3. Some additional advantages of leaky mode devices include: large aggregate bandwidth, polarization separation of signal light from noise, large angular deflection and frequency control of color1. In order to realize these advantages, it is necessary to be able to adequately characterize these devices as their operation is strongly dependent on waveguide and transducer parameters4. To characterize the modulators, the authors use a commercial prism coupler as well as a custom characterization apparatus to identify guided modes, calculate waveguide thickness and finally to map the device's frequency input and angular output of leaky mode modulators. This work gives a detailed description of the measurement and characterization of leaky mode modulators suitable for full-color holographic video.

This work describes fabrication and characterization of anisotropic leaky mode modulators for holographic video.

Caractérisation des anisotropes Leaky mode Modulateurs pour Holovideo

Holovideo displays are based on light-bending spatial light modulators.  One such spatial light modulator is the anisotropic leaky mode modulator.  This ...

Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators

Dielectric microspheres can confine light and sound for a length of time through high quality factor whispering gallery modes (WGM). Glass microspheres can be thought as a store of energy with a huge variety of applications: compact laser sources, highly sensitive biochemical sensors and nonlinear phenomena. A protocol for the fabrication of both the microspheres and coupling system is given. The couplers described here are tapered fibers. Efficient generation of nonlinear phenomena related to third order optical non-linear susceptibility &#935;(3) interactions in triply resonant silica microspheres is presented in this paper. The interactions here reported are: Stimulated Raman Scattering (SRS), and four wave mixing processes comprising Stimulated Anti-stokes Raman Scattering (SARS). A proof of the cavity-enhanced phenomenon is given by the lack of correlation among the pump, signal and idler: a resonant mode has to exist in order to obtain the pair of signal and idler. In the case of hyperparametric oscillations (four wave mixing and stimulated anti-stokes Raman scattering), the modes must fulfill the energy and momentum conservation and, last but not least, have a good spatial overlap.

Efficient generation of nonlinear phenomena related to third order optical non-linear susceptibility &#935;(3) interactions in triply resonant silica microspheres is presented in this paper. The interactions here reported are: Stimulated Raman Scattering (SRS), and four wave mixing processes comprising Stimulated Anti-stokes Raman Scattering (SARS).

Stimulé Stokes et antistokes Raman Scattering dans microsphériques Galerie Whispering mode Resonators

Dielectric microspheres can confine light and sound for a length of time through high quality factor whispering gallery modes (WGM). Glass microspheres ...

Fiber Optic Distributed Sensors for High-resolution Temperature Field Mapping

The reliability of computational fluid dynamics (CFD) codes is checked by comparing simulations with experimental data. A typical data set consists chiefly of velocity and temperature readings, both ideally having high spatial and temporal resolution to facilitate rigorous code validation. While high resolution velocity data is readily obtained through optical measurement techniques such as particle image velocimetry, it has proven difficult to obtain temperature data with similar resolution. Traditional sensors such as thermocouples cannot fill this role, but the recent development of distributed sensing based on Rayleigh scattering and swept-wave interferometry offers resolution suitable for CFD code validation work. Thousands of temperature measurements can be generated along a single thin optical fiber at hundreds of Hertz. Sensors function over large temperature ranges and within opaque fluids where optical techniques are unsuitable. But this type of sensor is sensitive to strain and humidity as well as temperature and so accuracy is affected by handling, vibration, and shifts in relative humidity. Such behavior is quite unlike traditional sensors and so unconventional installation and operating procedures are necessary to ensure accurate measurements. This paper demonstrates implementation of a Rayleigh scattering-type distributed temperature sensor in a thermal mixing experiment involving two air jets at 25 and 45 &#176;C. We present criteria to guide selection of optical fiber for the sensor and describe installation setup for a jet mixing experiment. We illustrate sensor baselining, which links readings to an absolute temperature standard, and discuss practical issues such as errors due to flow-induced vibration. This material can aid those interested in temperature measurements having high data density and bandwidth for fluid dynamics experiments and similar applications. We highlight pitfalls specific to these sensors for consideration in experiment design and operation.

We demonstrate use of a fiber optic distributed sensor for mapping the temperature field of mixing air jets. The Rayleigh scattering-based sensor generates thousands of data points along a single fiber to provide exceptional spatial resolution that is unattainable with traditional sensors such as thermocouples.

Fibre optique Capteurs distribués pour haute résolution cartographie des champs de température

The reliability of computational fluid dynamics (CFD) codes is checked by comparing simulations with experimental data. A typical data set consists ...

Nanostructured Ag-zeolite Composites as Luminescence-based Humidity Sensors

Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high external quantum efficiencies (EQE) and spans the whole visible spectrum. It has been recently reported that the UV excited luminescence of partially Li-exchanged sodium Linde type A zeolites [LTA(Na)] containing luminescent silver clusters can be controlled by adjusting the water content of the zeolite. These samples showed a dynamic change in their emission color from blue to green and yellow upon an increase of the hydration level of the zeolite, showing the great potential that these materials can have as luminescence-based humidity sensors at the macro and micro scale. Here, we describe the detailed procedure to fabricate a humidity sensor prototype using silver-exchanged zeolite composites. The sensor is produced by suspending the luminescent Ag-zeolites in an aqueous solution of polyethylenimine (PEI) to subsequently deposit a film of the material onto a quartz plate. The coated plate is subjected to several hydration/dehydration cycles to show the functionality of the sensing film.

A protocol for the synthesis of moisture-responsive luminescent Ag-zeolite composites is described in this report.

Composites nanostructurés Ag-zéolite comme Capteurs d&#39;humidité à base de Luminescence

Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high ...

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape method or individual WS2 nanotubes by dispersing the suspension of WS2 nanotubes. The selected samples have been fabricated into devices by the use of the electron beam lithography and electrolyte is put on the devices. We have characterized the electronic properties of the devices under applying the gate voltage. In the small gate voltage region, ions in the electrolyte are accumulated on the surface of the samples which leads to the large electric potential drop and resultant electrostatic carrier doping at the interface. Ambipolar transfer curve has been observed in this electrostatic doping region. When the gate voltage is further increased, we met another drastic increase of source-drain current which implies that ions are intercalated into layers of WS2 and electrochemical carrier doping is realized. In such electrochemical doping region, superconductivity has been observed. The focused technique provides a powerful strategy for achieving the electric-filed-induced quantum phase transition.

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

Here, we present a protocol to control the carrier number in solids by using the electrolyte.

Contrôle de champ électrique des États électroniques dans WS2 nanodispositifs par électrolyte Gate

A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape ...

Ultrasonic Fatigue Testing in the Tension-Compression Mode

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on exposing the specimen to longitudinal vibrations on its resonance frequency close to 20 kHz. With use of this method, it is possible to significantly decrease the time required for the test, when compared to conventional testing devices usually working at frequencies under 200 Hz. It is also used to simulate loading of material during operation in high speed conditions, such as those experienced by components of jet engines or car turbo pumps. It is necessary to operate only in the high and ultra-high cycle region, due to the possibility of extremely high deformation rates, which can have a significant influence on the test results. Specimen shape and dimensions have to be carefully selected and calculated to fulfill the resonance condition of the ultrasonic system; thus, it is not possible to test the full components or specimens of arbitrary shape. Before each test, it is necessary to harmonize the specimen with the frequency of the ultrasonic system to compensate for deviations of the real shape from the ideal one. It is not possible to run a test until a total fracture of the specimen, since the test is automatically terminated after initiation and propagation of the crack to a certain length, when the stiffness of the system changes enough to shift the system out of the resonance frequency. This manuscript describes the process of evaluation of materials' fatigue properties at high-frequency ultrasonic fatigue loading with use of mechanical resonance at a frequency close to 20 kHz. The protocol includes a detailed description of all steps required for a correct test, including specimen design, stress calculation, harmonizing with the resonance frequency, performing the test, and final static fracture.

A protocol for ultrasonic fatigue testing in the high and ultra-high cycle region in axial tension-compression loading mode.

Ultrasons Fatigue Testing dans le Mode de traction-Compression

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on ...

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates

Here, we demonstrate a method of coating ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles on (001) SrTiO3 (STO) single-crystal substrates by radio frequency (RF) magnetron sputtering. LSMO nanoparticles were deposited with diameters from 10 to 20 nm and heights between 20 and 50 nm. At the same time, (Gd) Ba2Cu3O7&#8722;&#948; ((Gd) BCO) films were fabricated on both undecorated and LSMO nanoparticle decorated STO substrates using RF magnetron sputtering. This report also describes the properties of GdBa2Cu3O7&#8722;&#948;/ La0.67Sr0.33MnO3 quasi-bilayer films structures (e.g., crystalline phase, morphology, chemical composition); magnetization, magneto-transport, and superconducting transport properties were also evaluated.

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7ÃƒÂ¢Ã‹â€ &#039;ÃƒÅ½ ´/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 STO Single-crystal Substrates

Here, we present a protocol to grow LSMO nanoparticles and (Gd) BCO films on (001) SrTiO3 (STO) single-crystal substrates by radio frequency (RF)-sputtering.

Radio fréquence Magnetron Sputtering GdBa2Cu3O7−δ/ La0,67Sr0,33MnO3 quasi bicouche Films sur substrats monocristallins de SrTiO3 (STO)

Here, we demonstrate a method of coating ferromagnetic La0.67Sr0.33MnO3 (LSMO) nanoparticles on (001) SrTiO3 (STO) single-crystal substrates by radio ...

Hybrid Printing for the Fabrication of Smart Sensors

A method to combine additively manufactured substrates or foils and multilayer inkjet printing for the fabrication of sensor devices is presented. First, three substrates (acrylate, ceramics, and copper) are prepared. To determine the resulting material properties of these substrates, profilometer, contact angle, scanning electron microscope (SEM), and focused ion beam (FIB) measurements are done. The achievable printing resolution and suitable drop volume for each substrate are, then, found through the drop size tests. Then, layers of insulating and conductive ink are inkjet printed alternately to fabricate the target sensor structures. After each printing step, the respective layers are individually treated by photonic curing. The parameters used for the curing of each layer are adapted depending on the printed ink, as well as on the surface properties of the respective substrate. To confirm the resulting conductivity and to determine the quality of the printed surface, four-point probe and profilometer measurements are done. Finally, a measurement set-up and results achieved by such an all-printed sensor system are shown to demonstrate the achievable quality.

Here we present a protocol for the fabrication of inkjet-printed multilayer sensor structures on additively manufactured substrates and foil.

Hybride d’impression pour la Fabrication de capteurs intelligents

A method to combine additively manufactured substrates or foils and multilayer inkjet printing for the fabrication of sensor devices is presented. First, ...