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Developing stable and highly efficient thick-film organic solar cells (OSCs) is crucial for the large-scale commercial application of organic photovoltaics. A novel synergistic dilution strategy to address this issue, using Polymethyl Methacrylate (PMMA) -modified zinc oxide (ZnO) as the interfacial layer, is introduced. This strategy effectively mitigates oxygen defects in ZnO while also regulating the self-assembly process of the active layer to achieve an ordered distribution of donors and acceptors. In synergistic diluted devices, the dynamic disorder is reduced owing to the suppression of electron-phonon coupling, while the static disorder is suppressed by improved molecular stacking and enhanced intermolecular interactions. Consequently, the 300 nm PM6:L8-BO device post-synergistic dilution manifests a marked enhancement in device performance, achieving a photovoltaic power conversion efficiency (PCE) >17% with excellent thermal stability. A typical ternary system is selected to explore the general applicability of synergistic dilution strategy, the PCE has been enhanced significantly from 17.89% to 18.72%, which falls within the range of the highest values among inverted single junction OSCs. As a practical application that depends on the pivotal synergy between high efficiency and stability, this approach paves the way for large-scale implementation of OSCs and ensures cost-effectiveness., (© 2024 Wiley‐VCH GmbH.)

To clearly show how important the impact of side chains on organic solar cells (OSCs) is, we designed three acceptors IDIC-CxPh (x = 4, 5, or 6) via subtle side-chain regulation. Despite this small change, significant distinctions were detected. IDIC-C4Ph devices achieve an optimal efficiency of 13.94% under thermal annealing, but thermal-assistant solvent-vapor annealing hugely suppresses the efficiencies to 10%. However, the C6Ph side chain endows extremely disordered stacking orientations, generating moderate efficiencies of ~12.50%. Excitingly, the IDIC-C5Ph affords an unexpected two-channel π-π charge transport (TCCT) property, boosting the fill factor (FF) by up to 80.02% and efficiency to 14.56%, ranking the best among five-ring fused-ladder-type acceptors. Impressively, the special TCCT behavior of IDIC-C5Ph enables 470 nm thick-film OSC with a high FF of up to 70.12% and efficiency of 13.01%, demonstrating the great promise in fabricating large-scale OSCs. Public summary: • OSCs are a promising technology to transform the solar energy to electricity • This article reports an efficient TCCT photovoltaic material through subtle side-chain modification • The TCCT property enables 13% efficiency with FF reaching 70% in 470 nm thick-film photovoltaics

The measurement of the thermoelastic properties of enamel thick films deposited onto soda‐lime silicate glass is challenging. The film properties can be modified by the interdiffusion between the glass substrate and the enamel and by the crystallization that occur during the sintering. The average biaxial modulus and coefficient of thermal expansion of several enamel thick films deposited onto 700 µm glass substrates have been simultaneously measured using the curvature method. The value of the coefficient of thermal expansion measured with a dilatometer on enamel bulk samples is significantly higher, associated with the absence of diffusion and a different enamel structure. The interdiffusion of elements between the enamel film and the glass substrate has been demonstrated with Time‐of‐Flight Secondary Ion Mass Spectrometry (TOF‐SIMS). The amount of porosity ratio presents in the enamel film, evaluated via Scanning electron microscopy(SEM), has a great influence on the biaxial modulus. The amount of compressive stress in the enamel, calculated from the film thermoelastic properties, is strongly correlated with the mechanical performance of enameled glasses, investigated by Ring On Ring methods. Therefore, a high Young's modulus for the enamel and a mismatch of the coefficient of thermal expansion between the enamel film and substrate, the film having the lowest value, has been found to increase significantly the mechanical performance of the stack. [ABSTRACT FROM AUTHOR]

Reproducibility of the sensor response is one of the fundamental themes for obtaining marketable devices with a high degree of reliability. This parameter becomes decisive especially if the sensor signals are used to identify compound mixtures by means of recognition algorithms. In fact, to apply the same algorithm to different devices, sensors must be identical within a minimum error margin. This point became crucial for medical diagnostic tools, e.g., for cancer screening and monitoring. A set of three thermo-activated thick-film Zinc Oxide (ZnO) sensors, obtained from the same screen-printing deposition, have been tested in laboratory with diverse gases and two biological fecal samples. Fecal samples have been employed in the clinical validation protocol of a device for non-invasive colorectal cancer pre-screening, as emitters of oncologic volatile biomarkers. Sensors showed a good reproducibility degree, with an error lower than 10% of response value for all compounds, reaching 1%–2% for some gases. [ABSTRACT FROM AUTHOR]

Tellurium‐based screen‐printable conductor metallization pastes containing multiple inorganic solid‐state frits (ie, metallization pastes containing two or more individual discrete tellurium‐based frits) were evaluated on p‐type, mono‐crystalline silicon passivated emitter rear cell (PERC) wafers. Individual discrete frits with tellurium‐lead‐metal‐oxygen compositions of TexPbyMzMz''Mzii1−xn+On+2 were prepared with varying ratios of tellurium and lead cations. Screen‐printed solar cells fabricated from metallization pastes containing multiple discrete frits (two, three, and four discrete frits) had state‐of‐the‐art solar cell electrical properties (Eff = 21.1%). Mechanisms for the oxidation, dissolution, and removal of the SiNx:H antireflective coating (ARC) by tellurium‐based metallizations during solar cell firing are examined. In situ thermal analysis of a model frit‐silicon nitride system shows that frit glass transition temperatures coincide with the onset of silicon nitride oxidation during heating in accord with dissolution reactions. The advantage of multiple frit systems is an inherent ability to fine‐tune the final chemistry of the conductor metallization, beyond what is possible with single frit systems, to further improve solar cell performance, which is essential for advanced crystalline silicon solar cell devices and continued reductions in processing costs. [ABSTRACT FROM AUTHOR]

Abstract A novel approach for deriving the thickness information from a rough and/or turbid thick film or coating is demonstrated. For the application where the roughness or inhomogeneity of the thickness layer produces a dominant speckle pattern, laser interferometry is often not a suitable technique for reliable thickness measurements. The implementation of a signal-to-noise ratio (SNR) enhancement algorithm, which can relate the spatial frequency information produced by the sample when illuminated by multiple lasers is demonstrated. Development of a metrology system using a specific laser interferometry setup to incorporate the noise-reduction technique is also presented. With respect to the detected information of the measurement system, this SNR enhancement technique allowed for the reliable identification of the proper frequency and thus the thickness of the sample. [ABSTRACT FROM AUTHOR]

A high-temperature thin/thick-film strain gauge (TFSG) shows development prospects for in situ strain monitoring of hot-end components due to their small perturbations, no damage, and fast response. Direct ink writing (DIW) 3D printing is an emerging and facile approach for the rapid fabrication of TFSG. However, TFSGs prepared based on 3D printing with both high thermal stability and low temperature coefficient of resistance (TCR) over a wide temperature range remain a great challenge. Here, we report a AgPd TFSG with a glass-ceramic protective layer based on DIW. By encapsulating the AgPd sensitive layer and regulating the Pd content, the AgPd TFSG demonstrated a low TCR (191.6 ppm/°C) from 50 to 800 °C and ultrahigh stability (with a resistance drift rate of 0.14%/h at 800 °C). Meanwhile, the achieved specifications for strain detection included a strain sensing range of ±500 με, fast response time of 153 ms, gauge factor of 0.75 at 800 °C, and high durability of >8000 cyclic loading tests. The AgPd TFSG effectively monitors strain in superalloys and can be directly deposited onto cylindrical surfaces, demonstrating the scalability of the presented approach. This work provides a strategy to develop TFSGs for in situ sensing of complex curved surfaces in harsh environments.

High-temperature electronics are required for applications such as automotive, down-hole drilling for oil and geothermal energy, aircraft, and space exploration. SiC and GaN devices are capable of operating in these high-temperature environments and challenging the packaging materials and technology to be compatible with these environments. Thick-film materials and technology have the potential of building reliable interconnections at high temperatures. This paper investigated the electrical reliability of two thick-film conductors (PtPdAu, Au) and two dielectrics at 300 °C. Test vehicles were fabricated with thick-film materials as capacitor and interdigitated finger test structures. For the test vehicles with PtPdAu thick-film, the leakage current of the capacitor structures with thin multilayer dielectrics increased in a short time during 300 °C aging with a 100-V bias, while the leakage current of capacitor structures with thick dielectrics had only a slight increase or remained constant during 300 °C aging with bias. Cross-sectional scanning electron microscopy and energy dispersive spectroscopy analysis showed that bismuth (Bi) in the PtPdAu paste diffused into the dielectrics from both the top and bottom conductors during the high-temperature firing steps in fabrication. If the Bi was continuous through the thin dielectric, the leakage current increased during aging with bias. The leakage current of the Au conductor in capacitor and interdigitated finger structures (both thick and thin dielectrics) did not increase with biased aging in high temperature. The Au conductor did not contain Bi. [ABSTRACT FROM PUBLISHER]

This paper is focused on reliability tests of non-trimmed miniaturized thin-film and thick-film resistors. Thick-film resistors are screen printed by polymer paste on LTCC (Low Temperature Co-fired Ceramic) substrate by two different approaches. Nonstandard precise screen printing process provide tolerance of resistivity less than 5% and thus further trimming is not necessary. OhmegaPly material with Nickel Phosphorous (NiP) metal alloy is used for thin-film resistors fabricated by subtractive process. Miniaturized resistors have dimensions 0.5 × 0.5 mm, and thus 1 square, with thickness 1 μm for thin-film and 20 μm for thick-film resistors. Stability of miniaturized resistors were tested by humidity test, thermal shocks, long-term thermal ageing, direct current stress, current pulses and simulation of soldering process using VPS (Vapour Phase Soldering). Resistivity of resistors is measured by four wire method before and after each set of test and relative change of resistivity is plotted in graphs. Influence of every test on each type of resistor is analysed. [ABSTRACT FROM AUTHOR]

A new approach has been proposed to overcome the electrode overpotential problem in the two-probe Hebb-Wagner polarization cell by dramatically increasing the shape factor of the polarization cell. To accurately estimate the electronic conductivity, a thick-film of gadolinium-doped ceria (GDC) has been fabricated using the tape casting technique, which sharply increases the shape factor of the sample. The bulk resistance of this thick-film cell is about two orders of magnitude higher than that of a bulk cell. In contrast to the bulk resistance, the electrode resistance remains nearly constant. Thus, the contribution of the electrode overpotential to the total resistance can be neglected in an in-plane geometry. The measured n -type conductivities ( σ n ) of GDC with the in-plane geometry are about 50% higher than those of GDC with the bulk geometry (two-probe technique), and those values are in good agreement with the values of GDC with the four-probe technique. Even though the contribution of the overpotential to the total resistance is about 50% in this study, in other cases this contribution can be much higher. This approach can reduce the contribution of the overpotential by more than two orders of magnitude by using the thick-film geometry in any case, and rule out the overpotential problem in the two-probe technique. [ABSTRACT FROM AUTHOR]

The electrochemical behaviour of a bismuth-containing gold thick-film, which was screen-printed and co-fired on low temperature co-fired ceramic (LTCC), has been investigated in 1 M nitric acid. After potentiostatic polarisation the material was electrochemically studied by voltammetry to determine the degradation kinetics and the role of elements of the glass-ceramic compounds. Field emission scattering electron microscopy (FESEM) examinations and energy dispersive X-ray (EDX) analyses confirm the electrochemically driven degradation of the composite: The interphase between the thick-film and the LTCC substrate was selectively attacked around the conductive gold layer. Elementary bismuth was reductively formed within the attacked area. Inverse voltammetric analyses of the electrolyte solution show that the electrochemical degradation is superimposed by chemical degradation of bismuth-containing glass-phases. The reductively formed bismuth was removed from the screen-printed electrode (SPE) due to the subsequently performed anodic polarisation. The amount of anodically dissolved bismuth is comparable with the coulometrically determined value of the anodic polarisation sweep. [ABSTRACT FROM AUTHOR]

The screen-printed (SP), reference electrode (RE) has been shown to be a crucial element of potentiometric sensors but it is also the stumbling block for reliable and accurate SP sensors. The easiest, most common and most environmentally friendly, type of RE is the Silver/Silver Chloride (Ag/AgCl) RE. Unfortunately, until now the only reliable RE of this kind is the conventional, liquid or gel-filled type. However, for most environmental and soil applications the use of the conventional RE is not an option, which raises the demand for a robust, rugged and low-cost version to replace the conventional RE. This paper presents a review of the various attempts to produce reliable, SP, Ag/AgCl REs, and explain why almost all of them never reach the commercialisation stage. The paper provides an overview of the main challenges that need to be overcome, details of the electrode’s construction, an analytical comparison of their performance in terms of chloride susceptibility, cross-sensitivity and lifetime, and their suitability in different applications depending on their performance characteristics. [ABSTRACT FROM AUTHOR]

The theory of cyclic voltammetry of ion transfer-electron transfer coupled reactions in a thick organic film modified electrode is developed. The model system consists of a planar electrode completely covered by an organic phase, which in turn is in contact with an aqueous phase, each containing a supporting electrolyte. It is shown that the coupling between the ion transfer-electron transfer processes at both, solid∣liquid and liquid∣liquid interfaces, has a marked effect on the shape of the voltammogram. The model allows the analysis of the system in different experimental conditions. In particular, the results for different concentration ratios of the redox probe and supporting electrolytes are presented. The variation of the potential of the solid∣liquid and the liquid∣liquid interfaces reflects changes in concentration of the species involved. This variation is presented as a descriptor of the shape of the voltammograms. The theoretical results are contrasted with experimental behaviour reported in literature. [ABSTRACT FROM AUTHOR]

A thick-film electrochemical sensor with an iridium-carbon working electrode was used for determining polyphenols and their antioxidant capacity in white wine. Caffeic acid was used as a model species because it has the ability to produce the highest oxidation current. The correlation coefficient of 0.9975 was obtained between sensor response and caffeic acid content. The total phenolic content (TPC) and scavenging activity on 1,1-diphenyl-2-pycrylhydrazyl (DPPH·) radical were also found to be strongly correlated with the concentration of caffeic acid, with a correlation coefficient of 0.9823 and 0.9958, respectively. The sensor prototype was proven to be a simple, efficient and cost effective device to evaluate the antioxidant capacity of substances.

A three-electrode based CO2 sensor was fabricated using thick-film technology. The performance of this sensor was further enhanced by incorporating platinum nanoparticles onto the working electrode surface. An eight-fold increase in the signal output was obtained from the electrode with the platinum nanoparticles. The sensing output was linearly related to the CO2 presented. Stability measurements demonstrated that the decline of the active surface area and the sensitivity of the sensor were 8% and 13%, respectively, over a two week period of time. The sensor response appeared to be a structural dependence of the crystallographic orientation of platinum electrode.

Air conditioning systems need permanent monitoring of the mass and energy flows in air ducts to assess their proper operation and detect and correct changes that may occur with time. This is a prerequisite for optimization in terms of energy efficiency. Such distributed monitoring systems require low-cost and robust flow sensors that must not be extremely precise, but give a good indication of the flow distribution within the air conditioning system. In this paper we present a novel flow sensor based on thick-film thermopiles deposited by silk-screen-printing on a plastic carrier. The flexible printed thermopile transducer was characterised in a flow channel to demonstrate the feasibility of the technology for air conditioning systems. The transducer exhibits a strictly increasing behaviour with increasing flow velocity, which is in good agreement to FEM simulations. [ABSTRACT FROM AUTHOR]

An existing miniaturized differential scanning calorimeter chip (DSC Chip) with a size of only 11 mm × 40 mm × 1.3 mm and a thermal resolution, which is comparable with conventional devices, served as a basis for this study. Due to its small dimensions and the high stability of the Low Temperature Co-fired Ceramics-based material (LTCC), fast heating rates up to 850 °C/min can be realized. Focus of this study are first approaches to integrate a mass sensing system onto the DSC chip, which allows determining mass specific thermal properties as well as mass changes during thermal analysis. By FEM analysis, the optimum position of the strain gauges was identified and the sensitivity of the mass sensing system was estimated in advance. The strain gauges were screen-printed and post-fired onto the structure. First tests show promising results in a mass measurement range of 8–200 mg. [ABSTRACT FROM AUTHOR]

Concrete carbonation is one of the main triggers of the corrosion process and hence of the premature deterioration of concrete reinforcements. In order to monitor and control the carbonation process, a potentiometric sensor using thick-film technology was developed. This paper includes the results of the research carried out to characterise the pH sensor, including the materials, response time, sensitivity, detection limit, reproducibility, reversibility and the study of chloride interference. The sensors have been studied in pore solutions and concrete specimens. The study shows that the thick-film sensor has a potentiometric response to variations in pH and is capable of providing continuous, real-time information on the progress of the carbonation front. [ABSTRACT FROM AUTHOR]

This work aims at a broad overview of the results obtained with metal-sulfide materials in the field of chemoresistive gas sensing. Indeed, despite the well-known electrical, optical, structural and morphological features previously described in the literature, metal sulfides present lack of investigation for gas sensing applications, a field in which the metal oxides still maintain a leading role owing to their high sensitivity, low cost, small dimensions and simple integration, in spite of the wide assortment of sensing materials. However, despite their great advantages, metal oxides have shown significant drawbacks, which have led to the search for new materials for gas sensing devices. In this work, Cadmium Sulfide and Tin (IV) Sulfide were investigated as functional materials for thick-film chemoresistive gas-sensors fabrication and they were tested both in thermo- and in photo-activation modes. Furthermore, electrical characterization was carried out in order to verify their gas sensing properties and material stability, by comparing the results obtained with metal sulfides to those obtained by using their metal-oxides counterparts. The results highlighted the possibility to use metal sulfides as a novel class of sensing materials, owing to their selectivity to specific compounds, stability, and the possibility to operate at room temperature. [ABSTRACT FROM AUTHOR]

In order to monitor the chloride penetration processes, a potentiometric embedded thick-film sensor was developed. This paper includes the results of research on the characterization of Cl − sensors made of Ag/AgCl resistive pastes (materials, sensitivity and detection limit, reproducibility, reversibility and response time, long-term performance and reliability in the presence of interfering agents). Theoretical expressions have been developed to describe the potentiometric response including the presence of OH − and bromide ions. The study shows that thick-film sensors are able to monitor Cl − activity as a function of the redox potential. Sensors are also capable of providing reliable and continuous real-time information on phenomena related to the progress of the chloride penetration front in concrete specimens. These sensors are a promising tool because thick-film technology allows us to obtain miniaturized, low-cost, robust and stable long-term sensors for Cl − monitoring. [ABSTRACT FROM AUTHOR]

This contribution presents the integration of glass-ceramic tapes on alumina substrates to increase the sensitivity of thermoelectric hydrocarbon gas sensors. Both ceramic materials have different thermal conductivity. Their combination into one sensor structure significantly improves the sensitivity by at the same time maintaining the excellent mechanical stability at high temperatures. Furthermore, this special technology allows for an easy integration of additional functional elements such as screen-printed thermocouples for temperature control purposes.

The integration of a mass detection system in an existing miniaturized differential scanning calorimeter device (DSC-MD) is shown in this study. With a size of only 11 mm x 40 mm x 1.3 mm, the DSC-MD exhibits a thermal resolution, which is comparable to conventional apparatuses. To allow for the determination of mass specific thermal properties, the integration of a mass sensing system based on screen-printed strain gauges onto the device was the focus of this work. By FEM-analysis, the device was simulated, the ideal positions of the strain gauges were identified, and the sensitivity of the mass sensing system was estimated. First tests show promising results in the range of 8 – 200 mg. [ABSTRACT FROM AUTHOR]

Electrochemical behavior of SiO electrode as a Na-ion battery anode was investigated by using thick-film electrodes without any binder or conductive additive. The SiO electrode reacted with Na to exhibit a reversible capacity of over 200 mA h g −1 at the first cycle, whereas Si electrode showed less capacity. We previously demonstrated that SiO being an amorphous material is composed of three-dimensional SiO 4 tetrahedral network similar to silica glass and Si clusters, and that the Si clusters are finely dispersed in the SiO 4 matrices. Given this characteristics, it is considered that the capacity obtained from the SiO originates from an alloying reaction of the Si clusters having a high surface energy with Na. [ABSTRACT FROM AUTHOR]

We prepared thick and dense-crystalline LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NMC) composite films at room temperature that can work well as cathodes in all-solid-state battery cells. The thick films were fabricated by aerosol deposition using NMC powder (D50 = 10.61 μm) as a source material. Commercially-obtained NMC powder did not form films at all on silicon wafer substrates, and cracking of the substrates was observed. However, a few tens of nanometer coating with amorphous niobium oxide resulted in the deposition of 7 μm-thick crystalline dense composite films. The films were successfully fabricated also on Li + -conductive glass-ceramic sheets with 150 μm in thickness, and all-solid-state batteries were fabricated. The solid-state battery provided a cathode-basis discharge capacity of 152 mAh g −1 (3.0–4.2 V, 0.025 C, 333 K) and repeated charge–discharge cycles for 20 cycles. [ABSTRACT FROM AUTHOR]

The influence of temperature distribution on the melting process in a ceramic differential scanning micro-calorimeter (MC-DSC) is shown. The MC-DSC chip is manufactured in low temperature co-fired ceramics technology (LTCC) as a three-dimensional device that includes all functions of a conventional DSC device. This study deals with the simulation-based optimization of the heater geometry for the second MC-DSC-chip generation to improve both sensitivity and selectivity. The influence of the heater geometry improvement was evaluated by simulation of the melting process of indium. The results suggest both higher sensitivities and higher selectivities. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this work was fabrication of a small energy harvester. Design/methodology/approach – The multilayer thermoelectric power generator based on thick-film and low temperature co-fired ceramic (LTCC) technology was fabricated. Precise paths printing method was used to fabricate Ag/Ni and Ag/PdAg thermocouples on a number of unfired LTCC tapes. The tapes were put together to form a multilayer stack. The via holes were used to make the electrical connections between adjacent layers. Finally, the multilayer stack was fired in the appropriate thermal profile. Findings – It consists of 450 thermocouples and generates output voltage of about 0.45 V and output electrical power of about 0.13 mW when a temperature difference along the structure is 135°C. In the paper, individual stages of energy harvester fabrication process as well as its output parameters are presented. Originality/value – Miniaturized thermoelectric energy harvester based on thick-film and LTCC technology was fabricated. As materials, metal-based pastes were used. This is the first paper where multilayer thermoelectric harvester, fabricated with the aid of LTCC technology, was described. [ABSTRACT FROM AUTHOR]

Studies on electromigration phenomenon in thick-film structures on alumina and LTCC substrates are presented in this paper. The effects of storage of Au and Ag electrode patterns in temperature range up to 300 °C under voltage bias were examined. The leakage characteristics of electrodes with 100 μm spacing at 50 V dc bias as a function of time and temperature are presented and analyzed. Scanning electron microscope (SEM) equipped with the energy-dispersive X-ray spectroscopy (EDX) detector was applied for determination of metal ions transport. Test structures with Au-based conductive material are much more resistant to electromigration than Ag-based layers. [ABSTRACT FROM AUTHOR]

Abstract: Perovskite-type Sm1−x Ca x FeO3 (x =0, 0.05, 0.20, 0.50, 0.75, 1.0) powders as sensor materials were prepared by a wet-chemical route using a polymer precursor method at 750°C. A perovskite-type oxide thick-film device prepared by a screen-printing method was used for an acetylene (C2H2) sensor for which outputs were measured by AC impedance spectroscopy at 400°C. Although sensitivities of the devices using oxides with Ca2+ substitution were decreased because of reduction in the amount of impedance change between air and sample gas, the device without Ca2+ substitution showed extremely high response at a low frequency. According to Nyquist's plots of the SmFeO3 device, this is attributed to the fact that impedance of charge transfer from the surface reaction was taken at a low frequency. It was also found that the sensor devices showed good selectivity to interference gases. [Copyright &y& Elsevier]

Highlights: [•] A Thick-Film (TF) sensor was manufactured. [•] TF sensor response is compared with strain foil gauge in 4PBT on steel bar. [•] Response of brick columns mounted with TF sensors are shown. [•] Mechanical simulation is used to verify the predictability of TF sensor response. [Copyright &y& Elsevier]

Highlights: [•] A miniaturised, low cost solid state reference electrode is developed. [•] Showing susceptibilities as low as +2mV/decade of chloride concentration in various potassium chloride solutions. [•] Their stability is also tested in a variety of pH buffer solutions resulting in susceptibilities in the range of +5mV/pH. [•] Satisfactory stability, therefore suitable for pH accuracies of ±0.1pH units over a modest chloride concentration range. [ABSTRACT FROM AUTHOR]

This paper discusses the robustness of the artificial immune recognition system (AIRS) for the gases/odors identification problem. The steady state responses of a thick-film sensor array with four sensor elements with exposure of four gases, viz., H2, CO, CH4, and LPG, are used as input data. The AIRS algorithm with its versions including AIRS1, AIRS2, and parallel AIRS is applied to classify the unseen gases/odors data with duly trained networks. The classification accuracy of the AIRS algorithm is compared with radial basis function neural network, naive bayes, and learning vector quantization methods. The results obtained with the AIRS are found more promising in this experiment. The results are verified using a cross-validation scheme. [ABSTRACT FROM PUBLISHER]

Abstract: The influence of the microstructure of screen-printed Ba0.6Sr0.4TiO3 ceramic thick-films on their microwave properties has been investigated. The Ba0.6Sr0.4TiO3 powders were synthesized through a sol–gel route. The spray-dried precursors were calcined at different temperatures. Scanning electron microscopy images and BET measurements revealed the primary particle size of calcined powder depending on the calcination temperature. The Ba0.6Sr0.4TiO3 thick-films showed different microstructure after sintering due to the use of two different calcined BST powders as well as varying the sintering conditions. Permittivity, dielectric loss and tunability of thick-films were characterized with coplanar waveguide structures up to 40GHz. A correlation of microstructure and microwave properties of the thick-films has been observed. Particularly the tunability could be improved by an optimized microstructure. [Copyright &y& Elsevier]

Abstract: A set of sensors based on nanostructured single and mixed metal oxides has been prepared and employed in acetaldehyde detection within 0.1–10ppm, this range being useful for many applications. Electrical characterization has been performed in laboratory at several working temperatures, in order to obtain the optimal operating condition. ZnO working within 450–550°C, was found to best respond to acetaldehyde. The response vs. concentration curves for all the sensors was a power law with an exponent of 0.5, compatible with the oxidation of acetaldehyde catalyzed by the surface. A decay in the sensor response to acetaldehyde due to humidity was observed and discussed. [Copyright &y& Elsevier]

Abstract: The influence of processing on the microstructure and the dielectric properties of Co–F-codoped Ba0.6Sr0.4TiO3 (BST) thick-films has been investigated. BST powders with different particle sizes were prepared and applied on alumina substrates by screen-printing. The resulting thick-films were sintered at different holding times and characterized with respect to their microstructure and microwave properties. The microstructure of the thick-films shows a clear dependency on sintering time and initial particle size. In addition to grain growth, the formation of a secondary phase is observed at the interface between substrate and BST with increasing sintering time. The dielectric characterization at microwave frequencies shows an increase of tunability with larger grain size while the dielectric loss is even lowered. This shows the strong influence of the microstructure on the material properties and the possibility of tailoring the material through specific processing. [Copyright &y& Elsevier]

Abstract: A portable electronic tongue has been developed using an array of eighteen thick-film electrodes of different materials forming a multi-electrode array. A microcontroller is used to implement the pattern recognition. The classification of drinking waters is carried out by a Microchip PIC18F4550 micro-controller and is based on neural networks algorithms. These algorithm are initially trained with the multi-electrode array on a Personal Computer (PC) using several samples of waters (still, sparkling and tap) to obtain the optimum architecture of the networks. Once it is trained, the computed data are programmed into the microcontroller, which then gives the water classification directly for new unknown water samples. A comparative study between a Fuzzy ARTMAP, a Multi-Layer Feed-Forward network (MLFF) and a Linear Discriminant Analysis (LDA) has been done in order to obtain the best implementation on a microcontroller. [Copyright &y& Elsevier]

This paper presents design, fabrication and testing of three LTCC (Low Temperature Co-fired Ceramics) based microfluidic systems. These microdevices are: enzymatic microreactor for urea determination, potentiometric sensor with ion selective electrodes (ISE) based array sensitive to potassium ions and amperometric glucose sensor. Performance of the presented LTCC-based microfluidic systems has been tested. All ceramic microdevices have revealed high output signal and large detection range. The properties of the presented LTCC-based microfluidic systems are comparable with similar ones made of silicon. Obtained results has shown that presented ceramic microsystems can work as a stand-alone device or can be integrated into a more sophisticated micro analysis system for in vivo or in vitro monitoring of various (bio)chemical compounds. [ABSTRACT FROM AUTHOR]