2,049 Works

P2.9.18 Electrochemical Cell Array for fast Sensor Evaluation

H. Fischer, J. Frank, N. Sauerbaum & G. Matz
Electrochemical cells are important gas sensors for different substances. Every cell is adapted to its target gas by variation of the electrolyte, the electrodes and filter. Due to unwanted chemical reactions, the cells inherit different cross sensitivities to other gases. In order to investigate these often undocumented reactions to different substances a sensor array was developed. The array can be equipped with up to six different electrochemical cells, to which the test substance is applied...

P2.9.17 A Wireless Interface for Nanowire-Based Gas Sensors

O. Monereo, J. Llosa, J. D. Prades, M. Martínez De Marigorta, I. Vilajosana & F. Hernandez-Ramírez
In this contribution we present an electronic system specially designed to perform conductometric measurements in chemical gas sensors based on individual nanowires operated in self-heated mode. Details about the precautions needed to be taken into account are thoroughly presented. The system is compact and low-power, it features autocalibration and auto-range capabilities and it is ready to be integrated in large networks of wireless sensors. It represents one of the first attempts to interface nanotechnology-based sensors...

P2.9.30 Building of a double-layered gas sensors array-based electronic nose to assess the freshness of fish

Han-Wen Kuo, Wang-Hsien Ding, Li-Chun Wang, Tseng-Hsiung Su, Cheng-Long Ho, Shih-Wen Chiu, Kea-Tiong Tang & Shang-Ren Yang
In this study, the main gas compositions of spoiled fish was found to be sulfide compounds rather than amine compounds by using Tenax TA trap followed by thermo desorption (TD) and gas chromatography/mass spectrometry (GC/MS). And then, a bio-inspired two-layer multiple-walled carbon nanotube (MWCNT)-polymer composite sensor system was developed to detect sulfide compounds especially dimethyl disulfide (DMDS), the major compound released from the spoiled fish. This double-layered gas sensors array shows excellent performance in reproducibility...

P2.9.16 Deactivation mechanism of alumina supported Pt and Pd catalysts for gas sensor by hexamethyldisiloxane (HMDSO)

Maiko Nishibori, Kimiko Katoh, Toshio Itoh, Noriya Izu & Woosuck Shin
The deactivation mechanism of Pt/gamma-alumina and Pd/gamma-alumina catalysts for gas sensor by hexamethyldisiloxane (HMDSO) exposure has been investigated. The chemical state and local structure of Pd in the catalysts has been characterized under the reduction and oxidation after HMDSO exposure by in situ X-ray absorption fine structure (XAFS) measurement. The Pd/gamma-alumina catalyst after HMDSO exposure hardly changed the chemical state of Pd even under the O2/N2 atmosphere though it oxidized easily under the O2/N2 atmosphere...

P2.9.31 Self-Organizing Water Quality Monitoring System Using Flooding Routing Protocol in Coastal Marine Area

Wan-Young Chung & Jae-Ho Yoo
The field server which gathers information of the water quality in coastal areas in wireless sensor network was designed and fabricated. Water pollution data is transmitted between field servers, and finally to the base station in self-organizing wireless sensor network. The collected data includes dissolved oxygen (DO), hydrogen ion exponent (pH), conductivity, turbidity, depth of water and temperature, by a water quality sensor module. The information provides real-time monitoring of water quality at the coastal...

P2.9.15 A Novel Compressive Sensing Based Electronic Nose of Gas Sensor Dynamic Signals

Guangfen Wei, Aixiang He & Yongqiang Wang
Feature parameter extraction and pattern recognition play important roles on performance of electronic noses. To solve the dilemma between features and original information, combined with a new compressive sensing (CS) theory proposed in recent years, a novel CS based electronic nose framework is proposed and the key technical problems are studied in this paper. Theoretic analysis and experimental results illustrate that gas information can be recognized efficiently and original signal can be recovered from the...

P2.9.32 Surface and subsurface FTIR-spectroscopic detection of critical parameters for adhesive bonding of CFRP

Roland Galos & Jürgen Kasberger
The presented work deals with preliminary investigations of contamination conditions prior the bonding procedure of carbon-fiber-reinforced polymer (CFRP) structures. As identified by airplane manufacturers, the monitoring of thermal damages and different contamination scenarios like moisture uptake and release agent and oil residues is required before bonding of CFRP. Here we are using FTIR-spectroscopic measurement systems in the mid infrared (MIR) wavelength region to monitor characteristic spectral features. In order to achieve the goal of monitoring...

P2.9.14 An artificial immune system model for gas sensors drift mitigation

Gabriele Magna, Eugenio Martinelli, Alexandro Catini, Arnaldo D'Amico, Corrado Di Natale, Saverio De Vito, G. Di Franci & Alexander Vergara
Nature is a continuous source of inspiration for problem solutions. To this regard, paradigms of the immune system have recently been implemented in several applications, where they show interesting potentialities and promising results. Herewith, an adaptive classification model inspired by algorithms modeled on the human immune system is introduced and applied to an array of gas sensors. The algorithm is found to be efficient to preserve gas recognition capabilities even in presence of significant drift....

P2.9.33 Unsupervised adjustment of centers in RBF networks for sensor drift compensation

Namyong Kim, Hyung-Gi Byun, Ki-Hyeon Kwon, Krishna C. Persaud & Jeong-Ok Lim
In our previous research for sensor drift compensation, the unsupervised signal processing approach of readjusting the weights of Radial Basis Function Network (RBFN) based on probability distribution functions (PDFs) has shown a possibility to solve the sensor drift problems, but it was not satisfactory still showing deteriorated distributions in some gases. In this paper, a new readjustment method for another parameter, center of RBFN based on PDFs is proposed for sensor drift compensation. Compared to...

P2.9.13 Temperature-controlled sensor transducer for planar four-wire impedance spectroscopy

G. Hagen, J. Kita, U. Röder-Roith, D. Schönauer-Kamin, R. Moos & N. Izu
We present a novel tool for fast sensor or materials testing. A planar electrode structure on alumina substrate with internal heater allows four-wire impedance spectroscopy measurements. One can easily distinguish between conduction / relaxation mechanism resulting from the bulk material or the electrode interface. Investigations of YSZ thick films prove the applicability of the presented system.

P2.9.12 A Cross-Platform Investigation of Hg-Au Response Profiles

M. J. Griffin, S. J. Ippolito, Y. M. Sabri, S. K. Bhargava, K. Kalantar-Zadeh & G. I. Matthews
The amalgamation of elemental mercury (Hg) with gold (Au) thin-films is a commonly utilized mechanism for sensing Hg vapor in air. In this work, we investigate and compare the sensing mechanisms of a resistive based sensor and a quartz crystal microbalance (QCM) which both employ an Au thin-film sensitive layer which was deposited under identical conditions. Both sensors were tested concurrently at several operating temperatures ranging between 30 and 130°C. Contrary to models described in...

P2.9.11 Monitoring of Obnoxious Odorants Generated from Pulp and Paper Industry using Electronic Nose

Sharvari Deshmukh, R. A. Pandey, Arun Jana, Nabarun Bhattacharyya & Rajib Bandyopadhyay
The Odorous emissions generated from pulp and paper industry has been the cause of nuisance since the inception of the industry. Reduced Sulphur Compounds generated from these mills have several health implications and the ever increasing population accompanied by other socio-economic factors leading to the development of habitant in the proximity of these mills is making it mandatory to monitor the emissions generated. Present day available analytical techniques do not depict clear picture of odor...

P1.7.16 CuO nanowire sensing at room temperature

Ivanna Tropper, Karina Pierpauli, Paolo N. Catalano, Juan Bonaparte, Patricia Bozzano, A. Gabriela Leyva, Hebe Durán, Alberto Lamagna & Carlos Rinaldi
CuO nanowires (NWs) based sensors were fabricated and characterized. Cuo NWs were synthesized by thermal oxidation and deposited onto gold electrodes. The sensing layer was morphologically characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showing a monocrystalline structure for CuO NWs. At room temperature these sensors exhibited a non-linear I-V response and showed sensitivity to different concentrations of ethanol. Results are important for low cost and low power consumption gas sensor fabrication.

P2.8.13 Nitrogen Dioxide Sensing Characteristics of Spin Coated Unsubstituted Copper Phthalocyanine Films

S. D. Chakane, A. M. Datir & V. S. Ghole
Copper phthalocyanine (CuPc) synthesized chemically was used for making CuPc thin films using spin coating technique. Spin coated films of unsubstituted CuPc films annealed at 150°C for 2 hrs were used to study NO2 gas sensing characteristics. a- phase of CuPc is noticed by X-ray diffraction and UV-Visible absorption spectra. IR spectra of undoped CuPc films and doped CuPc films with NO2 revealed that, doping of nitrogen dioxide modifies and deletes some of the bands....

P1.7.15 Design of a highly sensitive and selective C2H5OH sensor using p-type Co3O4 nanofibers

Ji-Wook Yoon, Joong-Ki Choi & Jong-Heun Lee
The Co3O4 nanofibers were prepared by electrospinning of solution containing Co-nitrate, N,N-dimethylformamide, and polyvinylpyrrolidone and subsequent heat treatment at 500, 600, and 700°C. The response to 100 ppm C2H5OH of Co3O4 nanofibers was significantly higher than those to 100 ppm CO, C3H8, and H2 in all three sensors. In particular, the Co3O4 nanofibers heat-treated at 500 and 600°C showed higher response and selectivity to C2H5OH. The variation of gas sensing characteristics were explained and discussed...

P2.8.12 Annealing Effects on the Gas Sensing Properties of Spin Coated Unsubstituted Copper Phthalocyanine Films

A. M. Datir, V. S. Ghole & S. D. Chakane
Unsubstituted copper phthalocyanine (CuPc) thin films were prepared using spin coating technique. The effects of post-deposition annealing of CuPc films on the NO2 gas sensing properties were studied. The results showed that the films annealed at 150 °C have highest sensitivity, highest response rate and lower response time. Sensitivity and response rate was decreased and response time was increased after the higher temperature (200 °C and above) annealing. The duration over which the films were...

P2.9.10 A Preliminary Study on Package of Catalytic Methane Sensor with Silica Aerogel

H. Y. Ma & E. J. Ding
The heat dissipation of catalytic combustion (pellistor) gas sensors through package has been neglected for a long time. Actually, the thermal isolation performances deserve to be taken into serious consideration. Due to the high sensing temperature and the quasi-closed metal package, a certain amount of thermal energy definitely lost from the pellistor sensors into ambience. If the thermal insulation ability of its package could be improved successfully, there would be a promising new approach to...

P 2.8.11 Synthesis, Characterization and Gas Sensing Applications of Metallophthalocyanines

R. M. Nanaware, S. R. Sasane, S. S. Veer, S. D. Chakane & A. M. Datir
Metallophthalocyanine of Ni was synthesized by chemical reaction from phthalic unhydride, urea and Nickel Chloride by using Ammonium Molybdate as a catalyst. The sample preparation was done by using press technique, in the form of pellets. The material was characterized by XRD, FTIR, UV visible and TGA techniques. The samples were checked with different concentrations of NO2 gas in presence of air. The sensitivity of these samples was checked by monitoring electric resistance of the...

P1.7.14 Au nanoelectrodes below nanostructured SnO2 films for acetone detection during breath analysis

M. Righettoni, A. Tricoliand & S. E. Pratsinis
New medical diagnostic methods such as non-invasive breath analysis bear the potential of drastically reducing medical costs as a greater amount of automatization is possible. Here, an asymmetric electrode assembly is described that increases the SnO2sensitivity and selectivity to acetone, a tracer for diabetes type-1, and reduces the resistance of the nanostructured SnO2layer. Gold nanoparticles serving as nanoelectrodes are stochastically deposited by flame spray pyrolysis (FSP) below a functional film decreasing the effective length of...

P2.9.8 Smart Trace Metal Monitoring System Using Homemade Voltammetric Controller and Nano Electrode Array

W. Zhang, Y. Zhao, H. Wan, X. Wang, H. X. Zhao, W. Cai & P. Wang
We present a smart trace metal monitoring system using homemade voltammetric controller and nano electrode array to detect heavy metal ions as Zn2+, Pb2+ and Cu2+. The voltammetric controller is featured with smart stage including pre-estimate and optimized measurement. The smart stage can be realized by integrated novel functions such as self-calibration, multi standard solution flow control and automatic deposition time adjustment. Moreover, a mercury-free nano electrode array, consisting gold and platinum electrodes on opposite...

P1.7.13 Highly Sensitive C2H5OH Sensors Using Self-Assembled ZnO Hierarchical Nanostructures

Kang-Min Kim, Hyo-Joong Kim, Hae-Ryong Kim, Kwon-Il Choi & Jong-Heun Lee
Three different morphologies of ZnO nanostructures such as as porous nanorods and two hierarchical structures were prepared by the reaction of mixtures of oleic-acid-dissolved ethanol solutions and aqueous dissolved Znprecursor solutions in the presence of NaOH and their gas sensing characteristics were investigated. Ultra-high responses (Ra/Rg = ~1200, Ra: resistance in air, Rg: resistance in gas) to 100 ppm C2H5OH was achieved using porous nanorods and hierarchical structures assembled from porous nanosheets. Gas sensing characteristics...

P2.9.7 Gas chamber design for multi chemical sensors

R. Rousier, S. Bouat, T. Bordy, H. Grateau, M. Darboux & P. Montméat
We present the design of a fluidic gas multi-sensors chamber to be integrated in a portable device for multi-modal detection and identification of gas. The multi-sensors chamber has 14 sensors; 4 fluorescent sensors, 2 Quartz crystal microbalances (QCM) and 8 surface-acoustic-wave sensors (SAW). The weight of the chamber is about 500 g with a 9 ml fluidic volume. We used the fluidic simulation to optimize the flow inside the chamber. The chamber design has been...

P2.8.10 Amperometric NO2 Sensor Based on Solid Polymer Electrolyte for Screen Printing Technology

P. Kuberský, R. Soukup, R. Vik, A. Hamácek & S. Nešpurek
Amperometric NO2 sensor with solid polymer electrolyte (SPE) and with a new type of carbon working electrode was developed. The electrolyte is based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM:TFSI] immobilized in poly(vinilidene fluoride) matrix. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum reference electrode. The sensor showed almost a linear behavior and its sensitivity was 2x10^-6 A/ppm in the whole tested range, i.e., 1 - 10 ppm. The rise/decay time was...

P1.7.11 Highly sensitive and rapid NO2 gas sensors based on ZnO nanostructures and the morphology effect on their sensing performances

A. Boudiba, C. Zhang, M. Debliquy, R. Snyders, D. Lahem & M.-G. Olivier
ZnO nanostructures with different morphologies (nanoparticles, nanorods) have been synthesized using different methods including chemical vapor deposition (CVD) and Sol-Gel. The obtained ZnO nanostructures have been characterized with TEM, SEM, XRD and XPS. Thick films based on the prepared ZnO nanostructures were coated on alumina substrates fitted with gold electrodes and a platinum heater. The responses to NO2 (= 1 ppm) of the different types of ZnO sensors have been studied at working temperatures ranging...

P2.9.6 Analog Wheatstone Bridge-Based Automatic Interface for Grounded and Floating Wide-Range Resistive Sensors

Andrea De Marcellis, Giuseppe Ferri & Paolo Mantenuto
An analog interface, based on a modified Wheatstone bridge configuration, for the automatic estimation of grounded and floating wide-range resistive sensors is here presented. The circuit maintains the simplicity of the traditional bridge topology but, through a suitable feedback loop, provides the continuous equilibrium condition employing a Voltage Controlled Resistor (VCR) that avoids any initial calibration. This feature allows the circuit to operate for a much larger variation of sensor resistances (with respect to the...

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