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Ethanol sensors based on different WO3 and ZnO structures are studied in the present work. The XRD and SEM processes are used to characterize the sensing layer’s surface morphology which reveals the presence of nanoparticle in sensing layer. Further reducing the nanoparticle diameter by the addition of palladium (Pd) and platinum (Pt) for both the sensors (ZnO and WO3) gives good results on sensitivity, operating temperature, response time and recovery time. Nanoparticle diameter for undoped WO3, Pd-modified WO3 and Pt-modified WO3 based sensors is 11.8, 6 and 5.4 nm, whereas nanoparticle diameter for undoped, Pd-modified and Pt-modified ZnO based sensors is 20, 14 and 11 nm, respectively. Analysis of dynamic response of the sensors when exposed to different concentrations of ethanol vapour (from 500 to 10,000 ppm) and various temperatures indicate the improvement in sensitivity up to 77.2% for WO3 and 74.6% for ZnO based sensors. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR)-based differential phase analysis has been presented. Real as well as complex plane analysis of resonance parameters have been undertaken for the optimum selection of metal thicknesses in a bimetallic SPR configuration working under both angular and spectral regime. Theoretically, we can characterize the aqueous solution in terms of this differential phase variation due to the variation of sample parameters such as concentration and temperature. In this respect, two case studies, namely, concentration of hemoglobin in human blood and sensing of temperature of water have been demonstrated and proposed theoretically. By monitoring the change of differential phase, proposed approach leads to a very sensitive measurement of concentration and temperature. [ABSTRACT FROM AUTHOR]

Present work reports the preparation, properties of polyaniline (PANI) thin film and its application as NO gas sensor opertable at room temperature. PANI was successfully synthesized via chemical oxidative polymerization technique using aniline as a monomer and ammonium persulphate (APS) as oxidant. PANI thin film sensor was fabricated on corning glass substrate using spin coating technique. The film was characterized by XRD, TEM, SEM, FTIR and UV-Visible. The PANI film was found to give maximum sensing response of ~12.10 towards 100 ppm NO gas having with fast response and recovery times as ~11 s and 7 min. [ABSTRACT FROM AUTHOR]

The two most important measurement categories in production are temperature and load. Therefore commercial sensors are applied in machinery as near as possible to the working parts. For a cost efficient production the integration of sensor elements directly on top of the surface in the heavily loaded regions is essential to get the real temperature and load distributions during the production process. Therefore a new multifunctional thin film sensor system is in development. This multilayer system combines thermoresistive sensor structures with piezoresistive ones and exists out of wear resistant carbon based layers (Bewilogua and Hofmann, Surf Coat Technol 242:214-225, 2014; Biehl et al. Thin Solid Films 515:1171-1175, 2006; Biehl et al. Microsystem Technologies, Springer, 2010; Biehl et al. Microsystem Technologies, Springer, 2014; Robertson, Daim Relat Mater 12:79-84, 2003). The sensor data will lead to a deeper process understanding, to optimization of simulation tools, to reduction of rejects and to an improvement of flexibility in production. [ABSTRACT FROM AUTHOR]

High-quality nanocrystalline (NC) SnO thin film was grown on SiO/Si substrate by sol-gel spin coating technique at low temperature. X-ray diffraction and field emission scanning electron microscopy results observed the high quality of the produced NC SnO thin film. A metal-semiconductor-metal (MSM) H gas sensor was fabricated utilizing palladium (Pd) metal and NC SnO thin film. Hydrogen (H) sensing capabilities of the NC SnO thin film were examined at room temperature (RT), and the sensitivity was 600 % in the presence of 1000 ppm of H. The sensing measurements for H gas at different temperatures (RT to 125 °C) were repeatable for over 50 min. The sensor showed a sensitivity of 1950 % at 125 °C upon exposure to 1000 ppm of H. A significant variation in the sensitivity of the NC SnO thin film sensor was noticed at different concentrations of H at different operating temperatures. These high sensitivities are attributed to the increase in adsorption/desorption of gas molecules, which were achieved by increasing the porosity of the NC SnO thin film surface by adding glycerin to the sol solution. The high sensitivity of this H gas sensor at RT indicated that it has the capability to be used as a portable RT gas sensor. [ABSTRACT FROM AUTHOR]

Paper-based scaffolds are an attractive material for generating 3D tissue-like cultures because paper is readily available and does not require specialized equipment to pattern, cut, or use. By controlling the exchange of fresh culture medium with the paper-based scaffolds, we can engineer diffusion-dominated environments similar to those found in spheroids or solid tumors. Oxygen tension directly regulates cellular phenotype and invasiveness through hypoxia-inducible transcription factors and also has chemotactic properties. To date, gradients of oxygen generated in the paper-based cultures have relied on cellular response-based readouts. In this work, we prepared a luminescent thin film capable of quantifying oxygen tensions in apposed cell-containing paper-based scaffolds. The oxygen sensors, which are polystyrene films containing a Pd(II) tetrakis(pentafluorophenyl)porphyrin dye, are photostable, stable in culture conditions, and not cytotoxic. They have a linear response for oxygen tensions ranging from 0 to 160 mmHg O, and a Stern-Volmer constant ( K) of 0.239 ± 0.003 mmHg O. We used these oxygen-sensing films to measure the spatial and temporal changes in oxygen tension for paper-based cultures containing a breast cancer line that was engineered to constitutively express a fluorescent protein. By acquiring images of the oxygen-sensing film and the fluorescently labeled cells, we were able to approximate the oxygen consumption rates of the cells in our cultures. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This present study focuses on the effect of addition of CoCl-BaCl fillers on the β phase formation and dielectric constant in the PVDF composite films. The pristine and filler based PVDF films were prepared using solution casting technique. XRD analysis were carried out to investigate the crystalline structure in the prepared composite films. The surface morphology of the films were observed using SEM indicating the formation of agglormated structures. The UV-Vis absorption spectrum was obtained to investigate the effect of filler concentration on the optical band gap. The decrease in optical band gap with increase in filler concentration was confirmed from Tauc plot. The incorporation of filler significantly improved the ac conductivity. The dielectric study reveals the increase in value of dielectric constant from 10.8 to 42.3 as the filler content increased from 0 to 12 wt%. A pressure measurement set up was developed and voltage output was measured from the PVDF thin film sensor for variation in applied pressure. [ABSTRACT FROM AUTHOR]

Thin film sensor systems based on hydrogenated carbon have the advantage to combine two very important characteristics in order to be used in measurement engineering: Firstly, the sensory layer demonstrates piezoresistive behavior and secondly its good properties related to hardness and wear resistance lead in a tribologically stable system. Therefore, the thin film sensor systems can be applied into the main distribution of force within machine parts or used for universal interchangeable sensor systems, e.g. sensory washers. In this article the deposition of a self-contained thin film sensor system on a large technical component (spindle shaft) is shown. The spindle shaft with a length of 480 mm and an outer diameter of 90 mm is part of a belt driven machining spindle for planing machines in woodworking industries. In order to establish a measurement system, which allows monitoring the clamping force of the tool holder and the imbalance of the mounted tool, the thin film sensor system was directly applied to the front surface of the spindle shaft. For this application a novel self-contained thin film sensor system was developed, which consists of an alumina layer for electrical isolation, a chromium layer to establish internal sensor electrodes, a piezoresistive hydrogenated carbon layer (1 μm) and a second covering wear resistance and insulation layer (silicon and oxygen modified carbon layer). The piezoresistive sensor layer and the top layer are part of the diamond like carbon layer family (Robertson, Diam Relat Mater 12:79-84, ; Bewilogua et al. DLC based coatings for tribological applications, pp. 67-75, ; Biehl et al. Thin Solid Films 515(3):1171-1175, , Novel measurement and monitoring system for forming processes based on piezoresistive thin film systems. Springer Verlag, pp. 879-883, ). [ABSTRACT FROM AUTHOR]

Industrial grade platinum resistance thermometers were calibrated in the temperature range from $$200\,^{\circ }\mathrm{C}$$ to $$700\,^{\circ }\mathrm{C}$$ . Both wire-wound and thin-film sensor-based thermometers were investigated. The purpose of the study was to investigate thermometers which could be used in future coal power plants. The calibrations were performed in a vertical cesium heat-pipe furnace and in a horizontal and vertical sodium heat-pipe furnace. The reference thermometer was a standard platinum resistance thermometer calibrated at fixed points up to the aluminum point. In addition to calibration, various thermal tests including immersion measurements and thermal-cycling tests were performed. The stability of the sensors was determined by monitoring the ice-point resistance. Possible contamination of the sensors was determined by measuring the resistance ratio $$R(30\,^{\circ }\mathrm{C})/R(10\,^{\circ }\mathrm{C})$$ several times during the measurement period. The calibration curves were compared with the ICE 60751 standard and International Temperature Scale 1990 (ITS-90) reference functions. Considerable changes were found in all tested thermometers. The wire-wound sensors were more stable than the thin-film sensors. [ABSTRACT FROM AUTHOR]