The advantages of HMDS (hexamethyldisilazane) APT-plasma films for sensor applications were explored producing films in a three-turn copper coil APT equipment. HMDS was introduced into the argon plasma at four different conditions. Additional flux of oxygen could modulate the presence of organic components in the film, the composition varying from pure inorganic oxides to organo-silane polymers. Oxygen promoted deposition rates as high as 900 nm/min on silicon, acrylic or piezoelectric quartz crystal substrates. Films with a clustered morphology and refractive index of 1.45 were obtained, mainly due to a silicon oxide structure. Raman spectroscopy and XPS data showed the presence of CHn and amorphous carbon in the inorganic matrix. The films were sensitive to the humidity of the air. The adsorptive capabilities of outstanding films were tested in a Quartz Crystal Microbalance (QCM). The results support that those films can be a useful and simple alternative for the development of sensors.

MPS-T1-15 # 1 Chemical and Biochemical Sensors Beyond Nernst Response of Sensitivity Enhancement on EIS pH Sensing Device by Multi-Programming. Aurelien Dominguez , YiTing Lin, Chao-Sung Lai* In this study, the effect of different stressing methods on an Electrolyte-Insulator-Semiconductor structure for pH sensing has been studied. The EIS device uses an intermediate trapping storage layer of silicon nitride for the high density of traps of the material. The stressing method consists in using a low field of opposite polarity to the initial stress field to have a relaxation effect on the neutral trap created during the original process [2-3] and to repeat the programming at regular interval of time. With this method we observeD a successful trapping of holes through a negative shift of the flatband voltage and an enhancement of the sensitivity beyond Nernst response, more than THE theoretical ideal case, from 30 mV/pH to 80 mV/pH. In the meantime, by multiple times programming, a great stability with double sensitivity enhancement and variation within ±2% on the sensitivity measurement suggests that this method meets the prerequisite for medical application. 1departement of electrical engineering, GRENOBLE INPPHELMA Grenoble, France 2Department of Electronic Engineering, Chang-Gung University, Taoyuan, Taiwan 3Biosensor Group, Biomedical Engineering Research Center, Chang Gung University, Taoyuan, Taiwan *Phone: +886-3-2118800 ext: 5607 Taiwan

This work aims at three different applications for the betterment of plasma generated-composite thin films: pre-mixing, spray formation in miniaturized structures and an increase in the performance of detector surfaces. Miniaturized structures were projected, simulated with FEMLAB (R) 3.2 software and then constructed. Clustered films made from tetraethoxysilane (TEOS) and nonafluoro(iso) butyl ether (HFE (R)) precursors were deposited on silicon, acrylic and quartz substrates for different kinds of film characterization/or in the projected structures. Physical and chemical characterization guided the selection of best films previous to/after UVC exposure. The active surfaces (plasma-deposited films) in structures were modified by UVC exposure and then tested. The applications include pre-mixing of liquids and/or spray formation, best results being obtained with surface covered by derivative-HFE films, which acted as passivation layers. Preliminary results show good humidity sensing for TEOS-derivative films.

A composite material of PAN (polyacrylonitrile), starch granules and dimethylformamide as solvent was used as a selective membrane for volatile organic compounds (VOCs) in gaseous phase. This composite was produced as a thin film obtained by spin-casting and as a fiber mat produced by electrospinning. The fiber mat was tested for adsorption of VOCs and water. Characterization used microscopy (electron scanning and optical) in order to evaluate the fiber morphology and the starch incorporation in the PAN matrix. Infrared spectroscopy was intended to determine the starch presence. Relative viscosity of the starch/PAN suspensions was measured in order to provide a model of composite fiber formation. Quartz crystal microbalance experiments determined VOCs and water adsorption. Fibers incorporated the starch granules, making the composite sensible to water; but VOCs were not detected. Therefore, the composite was found to be a good choice as selective barrier on sensors or microTAS protection purposes.

Due to transport phenomena, analyte adsorption on the detector surface can be hindered, which increases the detection limit. Therefore, this work aims the simulation, production and tests of a simple miniaturized structure that favors mixing on detector surfaces. The conception of the manufactured device is based on passive mixers. Mixing is improved by changing the surfaces properties of plasma deposited thin films. Hexamethyldisilazane (HMDS) and nonafluoro(iso)butyl ether (HFE) and codeposited HMDS/HFE plasma films were modified by ultraviolet (UVC) or beta radiation exposure (electron beam, 2 MeV, from 10 nA to 100 nA). Silicon, acrylics and piezoelectric quartz crystal (PQC) were used as substrates. Film characterization used profilemeter for thickness and ellipsometer for refractive index determinations; Raman, infrared (FTIR) and x-ray photoelectron (XPS) spectroscopies determined chemical composition. Optical, scanning electron (SEM) and atomic force (AFM) microscopies evaluated the film resistance toward ultraviolet light or beta radiation and cluster formation; cluster size were estimated using ImageJ software. Contact angle measurements tested hydrophobicity and the adsorption of volatile organic compounds (VOCs). Simulations of detector surfaces (based on PQC detection) and respective package used FEMLAB 3.2 software. All films are hydrophobic and adsorbent, even after exposition to ultraviolet radiation. HMDS films exposed to ultraviolet form a silicone-like structure whereas beta radiation exposure leads to carbon nodules formation. HFE films act as passive layer, even for beta radiation. Best design for surface modification has approximately a sinoidal shape.

Formation of oriented or aligned micro- and nanofibers using biocompatible materials opens the possibility to obtain engineered tissues that can be used in medicine, environmental engineering, security and defense, among other applications. Pectin, a heteropolysaccharide, is a promising material to be incorporated into the fibers because, besides being biocompatible, this material is also biodegradable and bioactive. In this work, the formation of oriented fibers using solutions containing pectin and polyethylene oxide (biocompatible polymers), and chloroform (as the solvent) is investigated. The injection of solution into an intense electric field defined between two parallel electrodes was used to obtain oriented fibers. This novel approach is a modification of the conventional electrospinning process. The presence of pectin in the fibers was confirmed by FTIR analysis. Fibers with diameters of hundreds of nanometers and several centimeters long can be collected. The incorporation of pectin leads to a higher variation of the diameter of the fibers, and a trend to larger fiber diameters. This behavior can be related to the presence of pectin clusters in the fibers. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.057203jes] All rights reserved.

The aim of this work was the production of a large surface area of hexamethyldisilazane (HMDS) plasma-deposited thin films and their applicability in a miniaturized structure useful for preliminary analysis of organic mixtures. The HMDS plasma films were produced with different surface areas and morphologies, and all films adsorbed polar and non-polar organic compounds. A low cost miniaturized structure was manufactured in glass using a Milling cutter and covered with HMDS plasma films. Good agreement was observed between simulation and experimental results on those microstructures. The observed different performance between pure and mixtures of organic compound samples suggests that the proposed system is a simple setup that could be useful for rough analysis of a fuel.

The aim of this work was to produce, to characterize and test selective membranes based on derivatives from organic fluorinated/silicon compounds. The produced composites presented silicon and fluorinated species on the surface. The morphology of these non uniform surfaces showed big domains in the micrometer scale but a closer view reveals structures also in the nanometer range. Contact angle measurements showed a mildly hydrophobic and organophilic surface. Polymeric tapes treated with this composite showed an increase on permeation rate for the organic compounds. An acrylic device that employed this modified polymeric tape was manufactured and used for sample pretreatment during chemical analysis.

Lap joints fabricated using Al2024T3/commercially pure Ag sheet couples with nylon fasteners were exposed to standard field tests in a tropical marine atmosphere for a total period of six months. Atmospheric conditions were recorded using a weather monitoring station. Simultaneously, samples were also exposed in a salt spray chamber according to ASTM B117 and GM 9540P standards. Corrosion data was obtained for monthly intervals for both field and laboratory samples. Weight loss, pitting characteristics and the nature of the corrosion products were evaluated. Corrosion mechanisms based on the observed atmospheric corrosion phenomena are proposed.

Precursor chemistry was found to have a dominant effect on the electrical properties of sol‐gel‐derived Pb0.85La0.15TiO3 (PLT15) thin films prepared using different precursor sources for lanthanum, namely, lanthanum acetate dissolved in acetic acid (LAA) and lanthanum 2‐methoxyethoxide in 2‐methoxyethanol (LMM). The LMM‐derived PLT15 films had lower dielectric constants (KLMM= 394, KLAA= 548, measured at 100 kHz, applying 500 mV oscillation voltage), poorer polarization hysteresis characteristics, and higher leakage current densities (JLMM∼ 1.5 × 10−7 A/cm2, JLAA∼ 2 × 10−9 A/cm2, measured at 10 kV/cm field). Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) measurements in conjunction with Fourier transformed infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) analyses indicate that better removal of C–O moieties are the key step to yield improved electrical properties in these films. Possibly, C–O moieties reduce the metallic oxides to their corresponding metals and the presence of the metallic constituent(s) (e.g., lead), in turn deteriorate the electrical properties. In line with these postulations it was found that, when the pyrolysis temperature is increased from 450° to 550°C, the organic contents of LMM‐derived films are reduced and their electrical properties are indeed comparable to that of the LAA‐derived films.

Paraelectric BaxSr1−xTiO3 (BST) (x = 0.5 and 0.6) thin films are attractive candidates for the fabrication of various microwave dielectric devices including phase shifters, resonators, filters, oscillators etc. In the present work we have studied the effect of annealing temperature and ambient on the epitaxial quality, surface morphology, dielectric, and phase shifter characteristics of BST thin films deposited on LaAlO3 substrates. The epitaxial quality of the film was markedly improved as the annealing temperature was increased from 1050 to 1100°C. The degree of phase shift increased from 221 to 328° (measured at 14.5 GHz applying a field of 30V/μm) with the improvement of the epitaxial quality of the film. The insertion loss was also increased with the increase in annealing temperature and therefore the effective phase shifter κ factor (defined by the ratio of the degree of phase shift and insertion loss) remained low (∼30°/dB), while annealing these films in N2 ambient significantly reduced the insertion loss, their dielectric breakdown was observed at relatively lower applied voltage as compared to air and oxygen annealed films. The observed electrical behavior was correlated with the composition, chemical state of the constituents and epitaxial quality of the films synthesized under different annealing conditions.

The effect of growth conditions such as substrate temperature and oxygen partial pressure on the microstructure and properties of pulsed laser deposited SBTN thin films on Si(100) and MgO(100) substrates have been studied. Crystallization of films begins at room temperature but, the obtained phase was non-ferroelectric. The influence of oxygen pressure (150 to 450 mTorr) on crystallinity of the films deposited on Si(100) at 750°C is negligible. XPS studies of as-deposited films reveal that the oxygen vacancies are preferably present near the Bi ions at the Bi2O2 layers and vary with substrate temperature and oxygen partial pressure. Also, XPS studies of Sr 3d core level for SBTN films suggest that the oxygen ions in the Sr(Ta/Nb)2O7 perovskite layers are much more stable than those in the Bi2O2 layers. Micro-Raman studies of SBTN films deposited below 700°C show Raman modes of a non -ferroelectric phase.

In the present work we have optimized the process parameters to yield homogeneous, smooth ruthenium oxide (RuO 2 ) thin films on silicon substrates by a solution deposition technique using RuCl 3 .×.H 2 O as the precursor material. Films were annealed in a temperature range of 300°C to 700°C, and it was found that RuO 2 crystallizes at a temperature as low as 400°C. The crystallinity of the films improves with increased annealing temperature and the resistivity decreases from 4.86µΩ-m (films annealed at 400°C) to 2.94pµΩ (films annealed at 700°C). Ageing of the precursor solution has a pronounced effect on the measured resistivities of RuO 2 thin films. It was found that the measured room temperature resistivities increases from 2.94µΩ-m to 45.7µΩ-m when the precursor sol is aged for aged 60 days. AFM analysis on the aged films shows that the grain size and the surface roughness of the annealed films increase with the ageing of the precursor solution. From XPS analysis we have detected the presence of non-transformed RuCl 3 in case of films prepared from aged solution. We propose, that solution ageing inhibits the transformation of RuCl 3 to RuO 2 during the annealing of the films. The deterioration of the conductivity with solution ageing is thought to be related with the chloride contamination in the annealed films.