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Sensors Journal, IEEE

Issue 3 • Date March 2008

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Displaying Results 1 - 25 of 25
  • [Front cover]

    Publication Year: 2008 , Page(s): C1
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    Freely Available from IEEE
  • IEEE Sensors Journal publication information

    Publication Year: 2008 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (36 KB)  
    Freely Available from IEEE
  • Table of contents

    Publication Year: 2008 , Page(s): 201 - 202
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    Freely Available from IEEE
  • Rapid, State-of-the-Art Techniques for the Detection of Toxic Chemical Adulterants in Water Systems

    Publication Year: 2008 , Page(s): 203 - 209
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (742 KB) |  | HTML iconHTML  

    Recent events have heightened awareness concerning potential hazardous threats to U.S. populace. The causes of concern include a possible contamination of water systems through harmful chemical agents resulting in sickness or death among consumers. To forestall the consequences of high-risk chemical contaminants that can potentially pollute our water resources, swift intervening measures need to be taken as a first line of defense. This aspect of environmental protection involves the design, testing, and installation of detection devices that protect U.S. water supply systems from toxic chemicals. These sensing devices are based on physical, chemical, biological, and radiological methods of detection. Traditional analytical tools are rather cumbersome, time-consuming, and expensive to operate. On the other hand, contemporary trends in the fight against toxic chemical threats to domestic and industrial water facilities comprise of sensors designed to achieve rapid, highly sensitive, and cost-effective detection, and intervention. This paper samples the state-of-the-art in detection techniques for toxic chemical antagonists with emphasis on heavy metals and cyanide compounds that can be potentially deleterious to U.S. water systems. The goal is to identify rapid, realistic and reliable methods, as early warning systems, to mitigate the effects of toxicants in water systems. View full abstract»

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  • Electronic Scheme for Multiplexed Dynamic Behavior Excitation and Detection of Piezoelectric Silicon-Based Micromembranes

    Publication Year: 2008 , Page(s): 210 - 217
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1466 KB) |  | HTML iconHTML  

    A new concept for a precise compensation of the static capacitance of piezoelectric silicon-based micromembranes is proposed. Combining analog and digital field-programmable gate array hardware elements with specific software treatment, this system enables the parallel excitation and detection of the resonant frequencies (and the quality factors) of matrices of piezoelectric micromembranes integrated on the same chip. The frequency measurement stability is less than 1 ppm (1-2 Hz) with a switching capability of 4 micromembranes/sec and a measurement bandwidth of 1.5 MHz. The real-time multiplexed tracking of the resonant frequency and quality factor on several micromembranes is performed in different liquid media, showing the high capability of measurement on dramatically attenuated signals. Prior to these measurements, calibration in air is done making use of silica microbeads successive depositions onto piezoelectric membranes surface. The mass sensitivity in air is, thus, estimated at, in excellent agreement with the theoretical corresponding value. View full abstract»

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  • Voltage Division Position Sensitive Detectors Based on Photoconductive Materials Part II: Device Performances and Experimental Results

    Publication Year: 2008 , Page(s): 218 - 224
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (729 KB) |  | HTML iconHTML  

    This second section is dedicated to gain more insight into the Voltage Division Position Sensitive Detector described in Part I of this work. Here, the discussion is taken from a design point of view. The linearity and rejection to light intensity variations are described on the practical situation of an incident light beam whose cross sectional dimensions could be negligible to the length of the sensor active area. The noise contribution due to the resistive nature of the detector is taken into account and discussed, too. According to the ideas here depicted, a sensor based on high-quality CVD-diamond film has been fabricated. The experimental results acquired for such specimens, under UV excimer laser or X-ray illumination, confirm the theoretical expectations. View full abstract»

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  • Brillouin-Based Distributed Temperature Sensor Employing Pulse Coding

    Publication Year: 2008 , Page(s): 225 - 226
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (234 KB) |  | HTML iconHTML  

    A distributed temperature sensor based on spontaneous Brillouin scattering and employing optical pulse coding has been implemented and characterized using a direct-detection receiver. The signal-to-noise ratio (SNR) enhancement provided by coding is analyzed, along with the influence of coding in stimulated Brillouin threshold. Simplex-coding using 127 bit codeword provides up to 7 dB SNR improvement, allowing for temperature sensing over 21 km of dispersion shifted fiber with 3.1 K resolution and 40 m spatial resolution, permitting to avoid the use of optical pulse amplification. View full abstract»

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  • Analytical Optimization of Optical Fiber Curvature Gauges

    Publication Year: 2008 , Page(s): 227 - 232
    Cited by:  Papers (9)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (750 KB) |  | HTML iconHTML  

    `The ldquocurvature gaugerdquo sensor monitors deflection of structures under mechanical loading in applications in which strain gauges have traditionally been used. Structural deflection-curvature is measured rather than material strain. The sensitive zone of the curvature gage is precision machined into the plastic optical fiber on grinding or milling machines. The cutout produced removes a part of the fiber core and introduces light loss that is related to the bend-radius of the fiber. This modulation mechanism is described analytically in this paper. Results relate the relative light loss to the fiber curvature for different parameters of the sensitive zone (depth, length, number of cuts, bend radius, and pitch of cuts). This allows a quantitative optimization of the gauge without having to produce thousands of sensors with slightly different combination of parameters in order to accomplish a similar objective experimentally. View full abstract»

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  • Temperature Dependent Characteristics of Nonreach-Through 4H-SiC Separate Absorption and Multiplication APDs for UV Detection

    Publication Year: 2008 , Page(s): 233 - 237
    Cited by:  Papers (7)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1055 KB) |  | HTML iconHTML  

    Silicon carbide (SiC) separate absorption multiplication region avalanche photodiodes (SAM-APDs) for UV detection in harsh environment applications were designed and fabricated. The devices were intentionally designed to operate under nonreach-through conditions in order to eliminate field-induced leakage current. The gain of 2500 and quantum efficiency of ~45% at room temperature were achieved at the wavelength of 290-300 nm for a packaged device with an active area of 1 x 1 mm2. The temperature dependency of the current-voltage characteristics and responsivity was examined in the temperature range from room temperature to 230degC. View full abstract»

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  • A New Wireless Sensor System for Smart Diapers

    Publication Year: 2008 , Page(s): 238 - 239
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (189 KB) |  | HTML iconHTML  

    This letter presents a new wireless sensor system for smart diaper application, which consists of an interrogator circuit, an antenna, and a passive LC resonating sensor tag. The wireless link between the interrogator circuit and the sensor tag is established through the inductive coupling. The wetting of the diaper shifts the resonating frequency of the sensor tag, changing the inductive link, and thus trigger an ldquoonrdquo or ldquooffrdquo condition reflected at the interrogator circuit. With suitable sensor tags, smart diapers can be achieved in a straightforward and low cost approach. View full abstract»

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  • Fringing Field Capacitance Sensor for Measuring the Moisture Content of Agricultural Commodities

    Publication Year: 2008 , Page(s): 240 - 247
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1817 KB) |  | HTML iconHTML  

    A fringing field capacitive sensor is described for measuring the moisture content (MC) and temperature of agricultural commodities. Sensor performance was characterized by mounting the device on handheld probes and in acrylic canisters to determine the dielectric constant and MC of wheat and corn. The handheld probes demonstrated a promising capability to measure the MC of grain in hoppers, truck beds, and cargo holds. It is proposed that the sensors be supported on cables in grain silos and storage bins to acquire in situ data for grain storage management and control of aeration systems. The sensor is watertight and constructed with corrosion resistant materials which allow MC measurements to be made of industrial materials, chemicals, and fuels. View full abstract»

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  • Highly Selective Potentiometric Membrane Sensor for Hg(II) Based on Bis(Benzoyl Acetone) Diethylene Triamine

    Publication Year: 2008 , Page(s): 248 - 254
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (296 KB) |  | HTML iconHTML  

    A new ion selective PVC membrane sensor is described based on bis(benzoyl acetone) diethylene triamine as a potentiometric sensor for Hg2+ ions. The membrane having bis(benzoyl acetone) diethylene triamine as an electroactive material, sodium tetraphenyl phthalate (NaTPB), and dibutyl phthalate (DBP) as an anion excluder in PVC matrix in the percentage ratio 4.21:2.11:60.25:33.43 (Ionophore:NaTPB:DBP:PVC) (w/w) of exhibits a linear response to Hg2+ of 1.0 times 10-6 to 1.0 times 10-1 M with a limit of detection of 3.7 times 10-7 M and with a slope of 29.8 plusmn 1.0 mV/decade over the pH range of 2.0-11.5. Selectivity coefficients for Hg(II) relative to a numbers of potential interfering ions were investigated. The sensor is highly selective for Hg2+ ions over a large number of mono-, bi-, and trivalent cations. Normal interferents like Ag+ and Cd2+ do not interfere in the working of the sensor. The sensor has been found to be chemically inert to other ions and showing a fast response time of 1 s and was used over a period of three months with a good reproducibility. The sensor was successfully applied to determine mercury(II) in water samples with satisfactory results. View full abstract»

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  • Determination of Lean Burn Combustion Temperature Using Ultraviolet Emission

    Publication Year: 2008 , Page(s): 255 - 260
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (855 KB) |  | HTML iconHTML  

    Measurements of the ultraviolet emission spectrum emitted from a lean burn premixed natural gas flame were taken over a range of flame temperatures using a fiber-optic/CCD spectrometer. Combustion temperatures were determined by two methods: by measuring the unburned oxygen in the exhaust and by calculating the temperature using the fuel and airflows. These temperatures were correlated to ratios composed of the integrated intensity of the long wavelength region of the OH band between 310 to 340 nm (ratio's numerator) and that between 305 and 310 nm (ratio's denominator). Average local combustor flame temperatures at the end of the combustion zone may then be determined by tracking these ratios during combustor operation. The sensitivity of these ratios yields a 0.8% change in the ratios every 20 degF with a precision of plusmn30 degF or plusmn1% at 3000 degF with 95 % confidence bounds demonstrating the feasibility of this technique for use as a potential control parameter for gas turbine combustors burning natural gas and air mixtures. This method is well suited for the low equivalence ratios (< 1) required to reduce NOx and CO emissions. Other methods using peak ratios of different emission bands exhibit nonlinearity, lower sensitivity and greater uncertainty. View full abstract»

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  • Energy Scavenging From Low-Frequency Vibrations by Using Frequency Up-Conversion for Wireless Sensor Applications

    Publication Year: 2008 , Page(s): 261 - 268
    Cited by:  Papers (52)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1571 KB) |  | HTML iconHTML  

    This paper presents an electromagnetic (EM) vibration-to-electrical power generator for wireless sensors, which can scavenge energy from low-frequency external vibrations. For most wireless applications, the ambient vibration is generally at very low frequencies (1-100 Hz), and traditional scavenging techniques cannot generate enough energy for proper operation. The reported generator up-converts low-frequency environmental vibrations to a higher frequency through a mechanical frequency up-converter using a magnet, and hence provides more efficient energy conversion at low frequencies. Power is generated by means of EM induction using a magnet and coils on top of resonating cantilever beams. The proposed approach has been demonstrated using a macroscale version, which provides 170 nW maximum power and 6 mV maximum voltage. For the microelectromechanical systems (MEMS) version, the expected maximum power and maximum voltage from a single cantilever is 3.97 muW and 76 mV, respectively, in vacuum. Power level can be increased further by using series-connected cantilevers without increasing the overall generator area, which is 4 mm2. This system provides more than an order of magnitude better energy conversion for 10-100 Hz ambient vibration range, compared to a conventional large mass/coil system. View full abstract»

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  • A Breath Ammonia Sensor Based on Conducting Polymer Nanojunctions

    Publication Year: 2008 , Page(s): 269 - 273
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (652 KB) |  | HTML iconHTML  

    We present an ammonia sensor for human breath analysis based on electrically conducting polymer nanojunctions. Each nanojunction is formed by bridging a pair of gold nanoelectrodes on a silicon chip separated by a small gap (<60 nm) with electrodeposited polyaniline. The signal transduction mechanism of the sensor is the change in the nanojunction conductance as a result of polymer dedoping by ammonia. The sensor response to human breath is validated by comparison with a reference method for detection of ammonium ion combined with an optimized breath ammonia trapping system. The nanojunction sensor is capable of in situ detection of parts per billion (ppb) levels of ammonia in human breath. View full abstract»

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  • A Sensitivity Model for Predicting Photonic Crystal Biosensor Performance

    Publication Year: 2008 , Page(s): 274 - 280
    Cited by:  Papers (15)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (703 KB) |  | HTML iconHTML  

    We present a model for predicting photonic crystal label-free biosensor performance based primarily on the spatial distribution of electromagnetic near fields at device resonance. To achieve maximum device sensitivity, the resonant fields can be shaped by careful choice of material and geometrical parameters. The effect of each property on the resonant mode profile, and consequently on sensor performance, is illustrated. A comparison of device sensitivity calculated by both the proposed model and direct rigorous coupled wave analysis simulation supports the validity of our model. View full abstract»

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  • Optical Fiber Humidity Sensors Using Nanostructured Coatings of SiO _{2} Nanoparticles

    Publication Year: 2008 , Page(s): 281 - 285
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (720 KB) |  | HTML iconHTML  

    In this paper, a new optical fiber humidity sensor based on superhydrophilic coating is proposed. The electrostatic self-assembly technique has been used to create a nanometric scale surface on the tip of a standard single-mode pigtail. The fabricated sensor has demonstrated a good linearity in the range from 40% to 98% of relative humidity (RH). A variation of 10 dB in reflected optical power is achieved with a response time of only 150 ms. Among other applications, this sensor is intended to be used for monitoring the human breathing, so high dynamic performances are required, specially in the higher RH ranges. View full abstract»

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  • Robust Intermediate Read-Out for Deep Submicron Technology CMOS Image Sensors

    Publication Year: 2008 , Page(s): 286 - 294
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3592 KB) |  | HTML iconHTML  

    In this paper, a CMOS image sensor featuring a novel spiking pixel design and a robust digital intermediate read-out is proposed for deep submicron CMOS technologies. The proposed read-out scheme exhibits a relative insensitivity to the ongoing aggressive scaling of the supply voltage. It is based on a novel compact spiking pixel circuit, which combines digitizing and memory functions. Illumination is encoded into a Gray code using a very simple yet robust Gray 8-bit counter memory. Circuit simulations and experiments demonstrate the successful operation of a 64 64 image sensor, implemented in a 0.35 CMOS technology. A scalability analysis is presented. It suggests that deep sub-0.18 will enable the full potential of the proposed Gray encoding spiking pixel. Potential applications include multiresolution imaging and motion detection. View full abstract»

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  • Quantum Dot-Based Biosensor for Detection of Human Cardiac Troponin I Using a Liquid-Core Waveguide

    Publication Year: 2008 , Page(s): 295 - 300
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (818 KB) |  | HTML iconHTML  

    Human cardiac Troponin I is one of three subunits of the cardiac Troponin complex that are released into the bloodstream upon injury to cardiac muscle, particularly myocardial infarction, where it is absent under normal conditions. Rapid, sensitive detection of blood borne Troponin I is extremely important for early detection of myocardial infarction. An optical biosensor has been proposed as a versatile, adaptable, and effective method for detection of Troponin I. The biosensor architecture utilizes fluorescence resonance energy transfer (FRET), a distance-dependent chemical signal transduction method that occurs between two fluorescent molecules, termed the donor and acceptor. In order to launch FRET, a donor-labeled protein A molecule is bound to an acceptor-labeled capture antibody. When exposed to the Troponin I antigen, the antibody-antigen binding event initiates a conformational change within the structure of the antibody. As this morphological change in the antibody takes place, the distance between the donor and acceptor changes, resulting in a measurable shift in energy transfer. In this study, quantum dots were utilized as the FRET donors to further increase the efficiency of the biosensor system and organic dyes were utilized as the acceptors. This sensing mechanism was then interfaced in a liquid-core waveguide (LCW) platform that was able to capture the resulting fluorescence to achieve highly sensitive and accurate measurements. The biosensor demonstrated an ample sensitivity to the analyte, achieving a lower limit of detection of approximately 32 nM in phosphate buffered saline and 55 nM in human plasma. A high degree of specificity was also observed when the response to cardiac Troponin I is compared with that of a nonspecific protein. Response time of the biosensor was determined to be less than 1 min; an expeditious time compared with other Troponin diagnostic assays. View full abstract»

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  • Sub ppm Detection of Hydrogen

    Publication Year: 2008 , Page(s): 301 - 307
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (575 KB) |  | HTML iconHTML  

    A light pulse technique and a field-effect device were used to detect small concentration steps of hydrogen in air. The detection limit was lower than 40 ppb, which is at least one order of magnitude lower than previously reported measurements (with field-effect devices) of hydrogen concentration in air. The device structure was a metal-insulator-semiconductor capacitor with a metal double layer with 17.5 nm Pd (upper layer) and 7.5 nm Pt on a SiO2 insulator and a Si substrate. View full abstract»

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  • Design of a Low-Power Micromachined Fluxgate Sensor Using Localized Core Saturation Method

    Publication Year: 2008 , Page(s): 308 - 313
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (617 KB) |  | HTML iconHTML  

    Design of a low-power micromachined ring-type flux- gate sensor with localized saturation cores has been made and optimized in this work. The design is accomplished by using the electromagnetic simulation software, MagnetTM, which is capable of establishing a quantitative connection between the sensor parameters and the geometrical parameters of the model. Using recently developed data extraction techniques, the design with low power (19 mW) and high sensitivity (590 V/T at 60 muT) can be achieved after a series of simulations. For comparison, an actual device has been fabricated with sensitivity of 650 V/T at 60 muT, power consumption of 14 mW. The good agreement between the simulation and the experimental results validate our new approach for the design of low-power fluxgate. In addition, measurements using a second-harmonics-based detection circuit have been performed so that the noise, stability, and perming effect of the fabricated device are explored. View full abstract»

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  • Removal of Nonspecifically Bound Proteins on Microarrays Using Surface Acoustic Waves

    Publication Year: 2008 , Page(s): 314 - 320
    Cited by:  Papers (17)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (612 KB) |  | HTML iconHTML  

    Nonspecific binding of proteins is an ongoing problem that dramatically reduces the sensitivity and selectivity of biosensors. We demonstrate that ultrasonic waves generated by surface acoustic wave (SAW) devices remove nonspecifically bound proteins from the sensing and nonsensing regions of the microarrays. We demonstrate our approach for controllably and nondestructively cleaning the microarray interface. In this work, SAWs were generated using 128 YX lithium niobate, chosen for its high coupling coefficient and efficient power transfer to mechanical motion. These waves propagating along the surface were coupled into specifically bound and nonspecifically bound proteins on a patterned surface of 40 mum feature size. Fluorescence intensity was used to quantify cleaning efficacy of the microarrays. Our results have shown that excess protein layers and aggregates are removed leaving highly uniform films as evidenced by fluorescence intensity profiles. Selected antigen-receptor interactions remained bound during the acoustic cleaning process when subjected to 11.25 mW of power and retained their efficacy for subsequent antigen capture. Results demonstrate near-complete fluorescence signal recovery for both the sensing and nonsensing regions of the microarrays. Of significance is that our approach can be integrated into existing array technologies where sensing and nonsensing regions are extensively fouled. We believe that this technology will be pivotal in the development and advancement of microsensors and their biological applications. View full abstract»

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  • IEEE Sensors 2008

    Publication Year: 2008 , Page(s): 321
    Save to Project icon | Request Permissions | PDF file iconPDF (626 KB)  
    Freely Available from IEEE
  • IEEE Foundation [advertisement]

    Publication Year: 2008 , Page(s): 322
    Save to Project icon | Request Permissions | PDF file iconPDF (303 KB)  
    Freely Available from IEEE
  • IEEE Sensors Council Information

    Publication Year: 2008 , Page(s): 323
    Save to Project icon | Request Permissions | PDF file iconPDF (31 KB)  
    Freely Available from IEEE

Aims & Scope

The IEEE Sensors Journal is a peer-reviewed, monthly online/print  journal devoted to sensors and sensing phenomena

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Krikor Ozanyan
University of Manchester
Manchester, M13 9PL, U.K.