The sol-gel-derived lead titanate (PbTiO3) membrane has been successfully applied as a novel pH-sensing layer to form the PbTiO3 gate ISFET (ion-sensitive field-effect transistor). There exhibit the excellent quasi-Nernstian response of 55-58 mV/pH, good surface adsorption and anticorrosion characteristics via the capacitance- voltage measurement of the electrolyte-insulator-semiconductor structure. At a specific pH concentration, the output and transfer characteristics of the PbTiO3 gate ISFET are very similar to the behaviours of MOSFETs (metal-oxide-semiconductor field-effect transistors), and the pH-ISFET model can be derived by the modified MOSFET model. As it operated in the nonsaturation region, there exhibits a linear pH response of about 55-58 mV/pH. Simultaneously, there exhibit the stable response time of 2-4 minutes, the drift of 0.5-1 mV/h, the hysteresis of 3-5 mV and the reduction rate of about ¡V10 mV/pH-day. On the other hand, as it operated in the saturation region, the pH responses and linearity can be controlled by adjusting the VGS values, e.g. the absolute pH response of 4.2, 24.8 and 31.3 uA/pH and the correlation coefficients of 0.9491, 0.9995 and 0.9996 at VGS= 1, 3 and 5 V can be obtained, respectively. Besides, the PbTiO3 gate ISFET has been modified by doping the Mg2+ and La3+ impurities into the PbTiO3 membrane. As a result, the former is a great benefit to improve the pH-sensing characteristics, which exhibits the pH response of 58-59 mV/pH, the drift of below 0.4 mV/h, the hysteresis of 1-3 mV and the reduction rate of -0.2 mV/pH-day. Finally, a digital pH meter has been successfully developed.

The Ta-modified niobate lithium [LiNb1-xTaxO3, abbreviated to LNT] thin films were deposited on Pt/Ti/SiO2/Si substrates by spin coating with sol-gel technology and rapid thermal processing in this thesis. 1,3 propanediol was used as solvent to minimize the number of cycles of spin coating and drying processes to obtain the desired thickness of thin film. By changing the Ta content (x=0~1), the effects of various processing parameters on the thin films growth are studied. The effects of various Ta content on the response of pyroelectric IR detector devices are studied also. Experimental results reveal that the Ta content will influence strongly on grain size, dielectricity, ferroelectricity and pyroelectricity of LNT thin films. With the increase of Ta content, the grain size of LNT thin film decreases slightly, and highly c-axis orientated LNT films have been obtained for x=0.2. With the increase of Ta content, The relative dielectric constant of LNT thin film increases from 33 up to 62. The dielectric loss (tand) increases from 0.00374 to 0.00686,Coercive Field (Ec) decreases from 81.09KV/cm to 32.07KV/cm, and Remanent polarization (Pr) decreases from 8.48 mC/cm2 to 2.2 mC/cm2, pyroelctric coefficient (g) increases from 2.76´10-8 C/cm2K up to 4.51´10-8 C/cm2K with an increase of Ta content. In addition, the results also show that the LNT thin film possesses the largest figures of merit Fv (2.66¡Ñ10-10 Ccm/J) and Fm (2.57¡Ñ10-8 Ccm/J) at the heating temperature of 700¢J and Ta content of 20mol%. The voltage responsivities (Rv) measured at 70 Hz has a largest value of 7020 V/W with the Ta content of 20mol%. The specific detectivity (D*) measured at 200 Hz has the maximum value of 7.76¡Ñ107 cmHz1/2/W with the Ta content of 20mol%. The results show that LNT(20) pyroelectric thin film detector exists both the maximums of voltage responsivity and specific detecivity. Therefore, optimizing the conditions of this study, LNT(20) thin film will be the most suitable for IR detector application.

Abstract Aqueous solution containing tin chloride as precusor was traditionally added with NH3(aq) to promote hydrolysis and hence condensation. This results in a particulate sol which possesses little viscosity and the aggregation of precusor particles makes the subsequcently spin-coated thin film very rough in the surface and poorly-adhered with the substrate. One objective of this work is to improve the film quality by refluxing the sol to reduce precursor aggregation, enhance hydrolysis and promote HCl(g) evaporation. Experimtntal results show that, after refluxing the sol with DI-water or methanol as solvent, one obtains better films when basic sol (NH3(aq) added) and SnCl2 precursor is used instead of acidic sol (HCl(aq)added) and SnCl4 precursor. Moreover, to further reduce the effect of Cl¡Ð ion in aggregation and increase viscosity, ethylene glycol was used as solvent and two-stage heating-stirring of the sol in 80 oC and 130 oC ~150 oC was carried out to promote generation of H2O(g) and HCl(g). The evaporation of H2O(g) and HCl(g) enhances the polymerization of precursor and increase the viscosity of the sol. The aggregation caused by Cl¡Ð ions is thus reduced due to the steric effect present in the polymerical sol. XRD, SEM, FT-IR , TGA and DSC were used to examine the evolution from sol to films. FT-IR results show that absorbtion peaks of the xerogel appear at 636 cm-1(O-Sn-O) and 500 cm-1 (Sn-O). XRD results of the calcined (4 hr) powders show that rutile (SnO2) crystallization starts at 200 oC for that derived from the SnCl2-containing sol while powder derived from the SnCl4-containing sol starts crystallization at 250 oC. However, grain growth is faster in powder derived from SnCl4-containing sol as their XRD peaks become sharper than that corresponding to SnCl2 precursor as calcination temperature is raised. Based on the examination of the evolution process, it is concluded that SnCl2 polymerizes in ethylene glycol as a one dimensional chain while SnCl4 forming a 3-D network after polymerizing in ethylene glycol.

The goal of this dissertation was to create a new class of DMFC targeted at high energy density and low loss for small electronic devices. In order for the DMFC to efficiently use all its fuel, with a minimum of balance of plant, a low-loss proton exchange membrane was required. Moderate conductivity and ultra low methanol permeability were needed. Fuel loss is the dominant loss mechanism for low power systems. By replacing the polymer membrane with an inorganic glass membrane, the methanol permeability was reduced, leading to low fuel loss. In order to achieve steady state performance, a compliant, chemically stable electrode structure was investigated. An anode electrode structure to minimize the fuel loss was studied, so as to further increase the fuel cell efficiency. Inorganic proton conducting membranes and electrodes have been made through a sol-gel process. To achieve higher voltage and power, multiple fuel cells can be connected in series in a stack. For the limited volume allowed for the small electronic devices, a noble, compact DMFC stack was designed. Using an ADMFC with a traditional DMFC including PEM, twice higher voltage was achieved by sharing one methanol fuel tank. Since the current ADMFC technology is not as mature as the traditional DMFCs with PEM, the improvement was accomplished to achieve higher performance from ADMFC. The ultimate goal of this study was to develop a DMFC system with high energy density, high energy efficiency, longer-life and lower-cost for low power systems.

The continuous trend towards mega-functional, high-performance and ultra-miniaturized system has been driving the need for advances in novel materials with superior properties leading to thin components, high-density interconnect substrates and interconnections. Power supply and management is becoming a critical bottleneck for the advances in such mega-functional systems because power components do not scale down with the rest of the system resulting in bulky and stand-alone power modules. Amongst the power components, thin film capacitors are considered the most challenging to integrate because of several manufacturability concerns. The challenges are related to process compatibility of high permittivity dielectrics with substrates and high surface area electrodes, yield, leakage and losses. This thesis focuses on novel thin film capacitor technologies that address some of these critical challenges. / Thesis advisor has approved the addition of errata to this item. The abstract text in the metadata record has been modified to match the document text.

L'étude des verres bioactifs constitue un domaine de recherche pluridisciplinaire aux enjeux considérables : la mise au point d'une nouvelle génération de biomatériaux, capables de se lier avec les tissus receveurs, de former un lien interfacial fort et d'aider l'organisme à se soigner lui-même grâce à une action directe sur les cellules. Les applications concernent particulièrement le comblement de défauts osseux en chirurgies orthopédique et dentaire. Dans cette optique, nous avons élaboré plusieurs verres bioactifs dans des systèmes de composition binaire SiO2–CaO, ternaires SiO2–CaO–P2O5 , et pour la première fois à notre connaissance des verres contenant du strontium SiO2–CaO–SrO et SiO2–CaO–P2O5–SrO. L'utilisation du procédé sol-gel comme voie de synthèse des verres bioactifs s'est révélée avantageuse, car permettant l'élaboration de matériaux nanoporeux, de grande pureté et homogénéité. La bioactivité in vitro des verres est avérée : au contact d'un milieu biologique, tous les matériaux élaborés induisent la formation d'une couche Ca-P-Mg sur une profondeur de quelques microns à leur surface. Nos travaux se distin-guent par l'utilisation des microsondes nucléaires PIXE-RBS pour la caractérisation de l'interface verre bioactif/milieu biologique; leur emploi a permis de réaliser des cartographies chimiques rendant possible l'étude des gradients de concentrations en éléments majeurs et traces à l'interface. De plus, des informations quantitatives sur la réactivité locale des verres ont été acquises. Ces données sont importantes pour évaluer les cinétiques et l'amplitude des réac-tions physico-chimiques impliquées dans le processus de bioactivité. Nous avons ainsi mis en évidence que le verre binaire est le plus prompt à réagir en ce qui concerne la dissolution de la matrice vitreuse et l'apparition de la couche riche en Ca et en P. Toutefois la plus lente décroissance du rapport Ca/P à l'interface verre/milieu biologique indique que la couche Ca-P-Mg éprouve des difficultés à évoluer vers une phase apatitique. Pour les verres contenant du phosphore, la désalcalinisation de la matrice et la formation de la cou-che phosphocalcique sont retardées ; cependant le calcul du rapport Ca/P à l'interface et le suivi de l'état de saturation du milieu biologique montrent que la couche Ca-P-Mg se développe plus rapidement en une couche de type apatiti-que. Concernant les verres dopés en Sr, nous avons démontré que leur capacité de dissolution est amoindrie et que la couche Ca-P-Mg se forme sur une profondeur plus réduite. Néanmoins, la couche évolue plus promptement en apa-tite d'après la rapide décroissance du rapport Ca/P. Nous avons également obtenu des preuves de la présence de Sr à l'interface verre/liquide et de la diffusion de cet élément dans le milieu biologique sous forme de traces. Grâce aux effets bénéfiques du strontium sur l'activité cellulaire et sur le cycle de remodelage osseux, ceci pourrait résulter en une bioactivité grandement améliorée pour les verres dopés en Sr en milieu vivant.

Le 6-triéthoxysilyl-1-hexyl-ferrocène est une molécule stable, pouvant se lier de manière irréversible aux polysiloxanes en croissance, et possédant des propriétés électrochimiques, pour pouvoir l'utiliser comme une nouvelle sonde rédox. Les études électrochimiques (voltammétrie cyclique, chronoampérométrie) confirment l'influence du type de catalyseur dans l'évolution des coefficients de diffusions des polysiloxanes en croissance (détermination du temps de gel et des structures des polymères en solutions). Les résultats préliminaires sur des électrodes modifiées semblent lier la nature du catalyseur à l'organisation des xérogels de silice (fractals, isotrope) et leurs propriétés électrochimiques. Pour les sols-gels hybrides à matrice ormosils et les sol-gels de titane/phosphonate, l'utilisation de sondes rédox appropriées permet de suivre l'évolution de ces systèmes complexes et montrent l'influence des différents paramètres lors de la formation de ces matériaux.

Zum gegenwärtigen Kenntnisstand bezüglich Solvatochromie, Sol-Gel Prozesse, und der Synthese von Polyketonen wird eine kurze Einführung gegeben. Die Synthesekonzeptionen funktionalisierter aromatischer Aminoketone wereden vorgestellt. Die neun Verbindungen wurden mittels Elementaranalyse, Röntgenstrukturanalyse, und spektroskopischen (NMR, UV/Vis, MS) Methoden aufgeklärt. Im Mittelpunkt der Untersuchungen steht die Untersuchung des Einflusses von unterschiedlichen Medien (Lösungmittel, Oberflächen, Sol-Gel Materialien und Nachbarnmoleküle im Kristall) auf die Lage der UV/Vis-Absorptionsmaxima verschiedener aromatischer Aminoketone. Die Ergebnisse der Untersuchungen liefern Informationen in Bezug auf das spezifische Solvatationsvermögen, die Polarität von Feststoffoberflächen, der Einfluss funktionaler Gruppen in aromatischen Aminoketonen auf die intermolekulare Wasserstoffbrückenbindungen in Kristallen, und über die Natur der Gast-Host-Wechselwirkungen. Auf der Basis von nucleophilen Substitutionsreaktionen wurden zwei verschiedene Prozesse für die Synthese von Ploy(benzophenone-co-piperazin) und der Kompositform entwickelt. Molekulare Strukturen und Eigenschaften konnten durch Elementaranalyse, mehrere spektroskopische (IR, Festkörper-NMR, UV/Vis, MALDI-TOF) Methoden, Zetapotentialmessungen in wässeriger Phase und thermogravimetrischen Bestimmungen charakterisiert werden.

Thèse doctorat : Optique et Laser : Strasbourg 1 : 2007. / Titre provenant de l'écran-titre. Bibliogr. 5 p.

Current MEMS development is driven by the need to develop various 'Miniaturized Total Chemical Analysis Systems ([mu]TAS), biological and chemical sensing, drug delivery, molecular separation, microfiltration, amplification, and sequencing systems. In this work, the use of flexural plate wave devices as an actuator has been investigated.This research was done with the aim of developing a platform to build FPW devices for use in System-On-Chip applications. It is well known that acoustic forces generated by a flexural plate wave (FPW) device can cause fluid motion, by the principle of acoustic streaming. Also the proven ability of FPW devices to cause mixing, filtration and to work as a chemical-biological sensor can be used towards building a micromachined [mu]TAS. The effects of the IDT finger width, spacing, aperture, membrane thickness, and driving conditions on the device performance was studied to understand the impact of IDT design on device performance.