Sensors

30 pages, 2700 KiB

Open AccessArticle

The Micro-Pillar Shear-Stress Sensor MPS³ for Turbulent Flow

by Sebastian Große^{1, 2,*} and Wolfgang Schröder¹

¹ Institute of Aerodynamics, RWTH Aachen University, Wüllnerstraße 5a, 52062 Aachen, Germany

² Laboratory for Aero and Hydrodynamics, Delft University of Technology, 2628 CA Delft, The Netherlands

Sensors 2009, 9(4), 2222-2251; https://doi.org/10.3390/s90402222 - 30 Mar 2009

Cited by 32 | Viewed by 17291

Abstract

Wall-shear stress results from the relative motion of a fluid over a body surface as a consequence of the no-slip condition of the fluid in the vicinity of the wall. To determine the two-dimensional wall-shear stress distribution is of utter importance in theoretical [...] Read more.

Wall-shear stress results from the relative motion of a fluid over a body surface as a consequence of the no-slip condition of the fluid in the vicinity of the wall. To determine the two-dimensional wall-shear stress distribution is of utter importance in theoretical and applied turbulence research. In this article, characteristics of the Micro-Pillar Shear-Stress Sensor MPS³, which has been shown to offer the potential to measure the two-directional dynamic wall-shear stress distribution in turbulent flows, will be summarized. After a brief general description of the sensor concept, material characteristics, possible sensor-structure related error sources, various sensitivity and distinct sensor performance aspects will be addressed. Especially, pressure-sensitivity related aspects will be discussed. This discussion will serve as ‘design rules’ for possible new fields of applications of the sensor technology. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Germany)

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19 pages, 2055 KiB

Open AccessReview

Visual Sensor Technology for Advanced Surveillance Systems: Historical View, Technological Aspects and Research Activities in Italy

by Gian Luca Foresti^*, Christian Micheloni, Claudio Piciarelli and Lauro Snidaro

Department of Mathematics and Computer Science University of Udine, via delle Scienze, 206, 33100 Udine, Italy

Sensors 2009, 9(4), 2252-2270; https://doi.org/10.3390/s90402252 - 30 Mar 2009

Cited by 14 | Viewed by 16162

Abstract

The paper is a survey of the main technological aspects of advanced visual-based surveillance systems. A brief historical view of such systems from the origins to nowadays is given together with a short description of the main research projects in Italy on surveillance [...] Read more.

The paper is a survey of the main technological aspects of advanced visual-based surveillance systems. A brief historical view of such systems from the origins to nowadays is given together with a short description of the main research projects in Italy on surveillance applications in the last twenty years. The paper then describes the main characteristics of an advanced visual sensor network that (a) directly processes locally acquired digital data, (b) automatically modifies intrinsic (focus, iris) and extrinsic (pan, tilt, zoom) parameters to increase the quality of acquired data and (c) automatically selects the best subset of sensors in order to monitor a given moving object in the observed environment. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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18 pages, 418 KiB

Open AccessReview

Small Magnetic Sensors for Space Applications

by Marina Díaz-Michelena

Payloads and Instrumentation Area, INTA-Instituto Nacional de Técnica Aeroespacial, / Ctra. de Torrejón a Ajalvir km 4.2, Madrid, Spain

Sensors 2009, 9(4), 2271-2288; https://doi.org/10.3390/s90402271 - 30 Mar 2009

Cited by 212 | Viewed by 28449

Abstract

Small magnetic sensors are widely used integrated in vehicles, mobile phones, medical devices, etc for navigation, speed, position and angular sensing. These magnetic sensors are potential candidates for space sector applications in which mass, volume and power savings are important issues. This work [...] Read more.

Small magnetic sensors are widely used integrated in vehicles, mobile phones, medical devices, etc for navigation, speed, position and angular sensing. These magnetic sensors are potential candidates for space sector applications in which mass, volume and power savings are important issues. This work covers the magnetic technologies available in the marketplace and the steps towards their implementation in space applications, the actual trend of miniaturization the front-end technologies, and the convergence of the mature and miniaturized magnetic sensor to the space sector through the small satellite concept. Full article

(This article belongs to the Special Issue Aerospace Sensor Systems)

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Graphical abstract

31 pages, 397 KiB

Open AccessReview

Electrochemical Sensors Based on Carbon Nanotubes

by A. J. Saleh Ahammad¹, Jae-Joon Lee^{1, 2,*} and Md. Aminur Rahman^2,*

¹ Department of Advanced Technology Fusion, Konkuk University, Seoul 143-701, Korea

² Department of Applied Chemistry, Konkuk University, Chungju 380-701, Korea

Sensors 2009, 9(4), 2289-2319; https://doi.org/10.3390/s90402289 - 30 Mar 2009

Cited by 334 | Viewed by 26899

Abstract

This review focuses on recent contributions in the development of the electrochemical sensors based on carbon nanotubes (CNTs). CNTs have unique mechanical and electronic properties, combined with chemical stability, and behave electrically as a metal or semiconductor, depending on their structure. For sensing [...] Read more.

This review focuses on recent contributions in the development of the electrochemical sensors based on carbon nanotubes (CNTs). CNTs have unique mechanical and electronic properties, combined with chemical stability, and behave electrically as a metal or semiconductor, depending on their structure. For sensing applications, CNTs have many advantages such as small size with larger surface area, excellent electron transfer promoting ability when used as electrodes modifier in electrochemical reactions, and easy protein immobilization with retention of its activity for potential biosensors. CNTs play an important role in the performance of electrochemical biosensors, immunosensors, and DNA biosensors. Various methods have been developed for the design of sensors using CNTs in recent years. Herein we summarize the applications of CNTs in the construction of electrochemical sensors and biosensors along with other nanomaterials and conducting polymers. Full article

(This article belongs to the Section Chemical Sensors)

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14 pages, 209 KiB

Open AccessArticle

An Integrated Photogrammetric and Spatial Database Management System for Producing Fully Structured Data Using Aerial and Remote Sensing Images

by Farshid Farnood Ahmadi^* and Hamid Ebadi

K.N. Toosi University of Technology, Faculty of Geodesy and Geomatics Engineering, Department of Photogrammetry and Remote Sensing, Tehran, -Iran, Islamic Republic of

Sensors 2009, 9(4), 2320-2333; https://doi.org/10.3390/s90402320 - 30 Mar 2009

Cited by 6 | Viewed by 16492

Abstract

3D spatial data acquired from aerial and remote sensing images by photogrammetric techniques is one of the most accurate and economic data sources for GIS, map production, and spatial data updating. However, there are still many problems concerning storage, structuring and appropriate management [...] Read more.

3D spatial data acquired from aerial and remote sensing images by photogrammetric techniques is one of the most accurate and economic data sources for GIS, map production, and spatial data updating. However, there are still many problems concerning storage, structuring and appropriate management of spatial data obtained using these techniques. According to the capabilities of spatial database management systems (SDBMSs); direct integration of photogrammetric and spatial database management systems can save time and cost of producing and updating digital maps. This integration is accomplished by replacing digital maps with a single spatial database. Applying spatial databases overcomes the problem of managing spatial and attributes data in a coupled approach. This management approach is one of the main problems in GISs for using map products of photogrammetric workstations. Also by the means of these integrated systems, providing structured spatial data, based on OGC (Open GIS Consortium) standards and topological relations between different feature classes, is possible at the time of feature digitizing process. In this paper, the integration of photogrammetric systems and SDBMSs is evaluated. Then, different levels of integration are described. Finally design, implementation and test of a software package called Integrated Photogrammetric and Oracle Spatial Systems (IPOSS) is presented. Full article

(This article belongs to the Section Remote Sensors)

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11 pages, 702 KiB

Open AccessArticle

Detection of Biomolecular Binding Through Enhancement of Localized Surface Plasmon Resonance (LSPR) by Gold Nanoparticles

by Hyung Min Kim¹, Seung Min Jin¹, Seok Kee Lee², Min-Gon Kim² and Yong-Beom Shin^2,*

¹ Fusion Biotechnology Research Center, KRICT, Daejeon 305-600, Republic of Korea

² BioMonitoring Research Center, Korea Research Institute of Bioscience and Biotechnology, Yusong-gu, Daejeon, 305–333, Korea

Sensors 2009, 9(4), 2334-2344; https://doi.org/10.3390/s90402334 - 30 Mar 2009

Cited by 60 | Viewed by 17106

Abstract

To amplify the difference in localized surface plasmon resonance (LSPR) spectra of gold nano-islands due to intermolecular binding events, gold nanoparticles were used. LSPR-based optical biosensors consisting of gold nano-islands were readily made on glass substrates using evaporation and heat treatment. Streptavidin (STA) [...] Read more.

To amplify the difference in localized surface plasmon resonance (LSPR) spectra of gold nano-islands due to intermolecular binding events, gold nanoparticles were used. LSPR-based optical biosensors consisting of gold nano-islands were readily made on glass substrates using evaporation and heat treatment. Streptavidin (STA) and biotinylated bovine serum albumin (Bio-BSA) were chosen as the model receptor and the model analyte, respectively, to demonstrate the effectiveness of this detection method. Using this model system, we were able to enhance the sensitivity in monitoring the binding of Bio-BSA to gold nano-island surfaces functionalized with STA through the addition of gold nanoparticle-STA conjugates. In addition, SU-8 well chips with gold nano-island surfaces were fabricated through a conventional UV patterning method and were then utilized for image detection using the attenuated total reflection mode. These results suggest that the gold nano-island well chip may have the potential to be used for multiple and simultaneous detection of various bio-substances. Full article

(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)

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7 pages, 274 KiB

Open AccessArticle

Digital Mirror Device Application in Reduction of Wave-front Phase Errors

by Yaping Zhang^1,*, Yan Liu² and Shuxue Wang³

¹ Department of Physics, School of Science, Kunming University of Science and Technology, No. 68, Wenchang Road, 121 Street, Kunming, Yunnan Province. ZIP: 650093, P.R. China

² Air Force Engineering University, Xi'an 710077, P.R. China

³ Kunming Metallurgy College, Kunming 650033, P.R. China

Sensors 2009, 9(4), 2345-2351; https://doi.org/10.3390/s90402345 - 30 Mar 2009

Cited by 4 | Viewed by 13138

Abstract

In order to correct the image distortion created by the mixing/shear layer, creative and effectual correction methods are necessary. First, a method combining adaptive optics (AO) correction with a digital micro-mirror device (DMD) is presented. Second, performance of an AO system using the [...] Read more.

In order to correct the image distortion created by the mixing/shear layer, creative and effectual correction methods are necessary. First, a method combining adaptive optics (AO) correction with a digital micro-mirror device (DMD) is presented. Second, performance of an AO system using the Phase Diverse Speckle (PDS) principle is characterized in detail. Through combining the DMD method with PDS, a significant reduction in wavefront phase error is achieved in simulations and experiments. This kind of complex correction principle can be used to recovery the degraded images caused by unforeseen error sources. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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11 pages, 445 KiB

Open AccessArticle

Preparation and Properties of Various Magnetic Nanoparticles

by Jana Drbohlavova^1,*

, Radim Hrdy¹, Vojtech Adam², Rene Kizek², Oldrich Schneeweiss³ and Jaromir Hubalek¹

¹ Department of Microelectronics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Údolní 53, 602 00 Brno, Czech Republic

² Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemědělská 1, 613 00 Brno, Czech Republic

³ Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 616 62 Brno, Czech Republic

Sensors 2009, 9(4), 2352-2362; https://doi.org/10.3390/s90402352 - 30 Mar 2009

Cited by 127 | Viewed by 18714

Abstract

The fabrications of iron oxides nanoparticles using co-precipitation and gadolinium nanoparticles using water in oil microemulsion method are reported in this paper. Results of detailed phase analysis by XRD and Mössbauer spectroscopy are discussed. XRD analysis revealed that the crystallite size (mean coherence [...] Read more.

The fabrications of iron oxides nanoparticles using co-precipitation and gadolinium nanoparticles using water in oil microemulsion method are reported in this paper. Results of detailed phase analysis by XRD and Mössbauer spectroscopy are discussed. XRD analysis revealed that the crystallite size (mean coherence length) of iron oxides (mainly γ-Fe2O3) in the Fe2O3 sample was 30 nm, while in Fe2O3/SiO2 where the ε-Fe2O3 phase dominated it was only 14 nm. Gd/SiO2 nanoparticles were found to be completely amorphous, according to XRD. The samples showed various shapes of hysteresis loops and different coercivities. Differences in the saturation magnetization (MS) correspond to the chemical and phase composition of the sample materials. However, we observed that MS was not reached in the case of Fe2O3/SiO2, while for Gd/SiO2 sample the MS value was extremely low. Therefore we conclude that only unmodified Fe2O3 nanoparticles are suitable for intended biosensing application in vitro (e.g. detection of viral nucleic acids) and the phase purification of this sample for this purpose is not necessary. Full article

(This article belongs to the Special Issue Tissue, Cell and Molecular Bioelectrochemistry - New Trends and Approaches)

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8 pages, 1328 KiB

Open AccessArticle

Fieldservers and Sensor Service Grid as Real-time Monitoring Infrastructure for Ubiquitous Sensor Networks

by Kiyoshi Honda^1,*, Aadit Shrestha¹, Apichon Witayangkurn¹, Rassarin Chinnachodteeranun¹ and Hiroshi Shimamura^2,*

¹ 1-Remote Sensing and GIS, Asian Institute of Technology (AIT), Pathumthani, Thailand

² Elab Experience Inc., Japan

Sensors 2009, 9(4), 2363-2370; https://doi.org/10.3390/s90402363 - 31 Mar 2009

Cited by 29 | Viewed by 13973

Abstract

The fieldserver is an Internet based observation robot that can provide an outdoor solution for monitoring environmental parameters in real-time. The data from its sensors can be collected to a central server infrastructure and published on the Internet. The information from the sensor [...] Read more.

The fieldserver is an Internet based observation robot that can provide an outdoor solution for monitoring environmental parameters in real-time. The data from its sensors can be collected to a central server infrastructure and published on the Internet. The information from the sensor network will contribute to monitoring and modeling on various environmental issues in Asia, including agriculture, food, pollution, disaster, climate change etc. An initiative called Sensor Asia is developing an infrastructure called Sensor Service Grid (SSG), which integrates fieldservers and Web GIS to realize easy and low cost installation and operation of ubiquitous field sensor networks. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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Graphical abstract

18 pages, 735 KiB

Open AccessArticle

Development of a Dynamic Web Mapping Service for Vegetation Productivity Using Earth Observation and in situ Sensors in a Sensor Web Based Approach

by Lammert Kooistra^*

, Aldo Bergsma, Beatus Chuma and Sytze De Bruin

Wageningen University, Centre for Geo-Information, Droevendaalsesteeg 3, NL-6708 PB Wageningen, The Netherlands

Sensors 2009, 9(4), 2371-2388; https://doi.org/10.3390/s90402371 - 31 Mar 2009

Cited by 19 | Viewed by 14988

Abstract

This paper describes the development of a sensor web based approach which combines earth observation and in situ sensor data to derive typical information offered by a dynamic web mapping service (WMS). A prototype has been developed which provides daily maps of vegetation [...] Read more.

This paper describes the development of a sensor web based approach which combines earth observation and in situ sensor data to derive typical information offered by a dynamic web mapping service (WMS). A prototype has been developed which provides daily maps of vegetation productivity for the Netherlands with a spatial resolution of 250 m. Daily available MODIS surface reflectance products and meteorological parameters obtained through a Sensor Observation Service (SOS) were used as input for a vegetation productivity model. This paper presents the vegetation productivity model, the sensor data sources and the implementation of the automated processing facility. Finally, an evaluation is made of the opportunities and limitations of sensor web based approaches for the development of web services which combine both satellite and in situ sensor sources. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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Graphical abstract

26 pages, 1783 KiB

Open AccessArticle

Thermal Actuation Based 3-DoF Non-Resonant Microgyroscope Using MetalMUMPs

by Rana Iqtidar Shakoor^1,*, Shafaat Ahmed Bazaz², Michael Kraft³, Yongjun Lai⁴ and Muhammad Masood Ul Hassan⁴

¹ Department of Chemical and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, Islamabad, Pakistan

² Faculty of Electronics Engineering, GIK Institute of Engineering and Applied Sciences, Topi, NWFP, Pakistan

³ School of Electronics and Computer Science, Southampton University, Highfield, Bld 86, 2033, Southampton, SO17 1BJ, UK

⁴ Department of Mechanical Engineering, Queens University, Kingston, ON, K7L 3N6, Canada

Sensors 2009, 9(4), 2389-2414; https://doi.org/10.3390/s90402389 - 1 Apr 2009

Cited by 17 | Viewed by 17664

Abstract

High force, large displacement and low voltage consumption are a primary concern for microgyroscopes. The chevron-shaped thermal actuators are unique in terms of high force generation combined with the large displacements at a low operating voltage in comparison with traditional electrostatic actuators. A [...] Read more.

High force, large displacement and low voltage consumption are a primary concern for microgyroscopes. The chevron-shaped thermal actuators are unique in terms of high force generation combined with the large displacements at a low operating voltage in comparison with traditional electrostatic actuators. A Nickel based 3-DoF micromachined gyroscope comprising 2-DoF drive mode and 1-DoF sense mode oscillator utilizing the chevron-shaped thermal actuators is presented here. Analytical derivations and finite element simulations are carried out to predict the performance of the proposed device using the thermo-physical properties of electroplated nickel. The device sensitivity is improved by utilizing the dynamical amplification of the oscillation in 2-DoF drive mode using an active-passive mass configuration. A comprehensive theoretical description, dynamics and mechanical design considerations of the proposed gyroscopes model are discussed in detail. Parametric optimization of gyroscope, its prototype modeling and fabrication using MetalMUMPs has also been investigated. Dynamic transient simulation results predicted that the sense mass of the proposed device achieved a drive displacement of 4.1µm when a sinusoidal voltage of 0.5V is applied at 1.77 kHz exhibiting a mechanical sensitivity of 1.7μm /^o/s in vacuum. The wide bandwidth frequency response of the 2-DoF drive mode oscillator consists of two resonant peaks and a flat region of 2.11 kHz between the peaks defining the operational frequency region. The sense mode resonant frequency can lie anywhere within this region and therefore the amplitude of the response is insensitive to structural parameter variations, enhancing device robustness against such variations. The proposed device has a size of 2.2 x 2.6 mm², almost one third in comparison with existing M-DoF vibratory gyroscope with an estimated power consumption of 0.26 Watts. These predicted results illustrate that the chevron-shaped thermal actuator has a large voltage-stroke ratio shifting the paradigm in MEMS gyroscope design from the traditional interdigitated comb drive electrostatic actuator. These actuators have low damping compared to electrostatic comb drive actuators which may result in high quality factor microgyroscopes operating at atmospheric pressure. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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22 pages, 375 KiB

Open AccessArticle

A Feature Extraction Method Based on Information Theory for Fault Diagnosis of Reciprocating Machinery

by Huaqing Wang^{1, 2} and Peng Chen^2,*

¹ School of Mechanical & Electrical Engineering, Beijing University of Chemical Technology Chao Yang District, Beijing, 100029, P.R. China

² Graduate School of Bioresources, Mie University/1577 Kurimamachiya-cho, Tsu, Mie, 514-8507, Japan

Sensors 2009, 9(4), 2415-2436; https://doi.org/10.3390/s90402415 - 1 Apr 2009

Cited by 48 | Viewed by 14445

Abstract

This paper proposes a feature extraction method based on information theory for fault diagnosis of reciprocating machinery. A method to obtain symptom parameter waves is defined in the time domain using the vibration signals, and an information wave is presented based on information [...] Read more.

This paper proposes a feature extraction method based on information theory for fault diagnosis of reciprocating machinery. A method to obtain symptom parameter waves is defined in the time domain using the vibration signals, and an information wave is presented based on information theory, using the symptom parameter waves. A new way to determine the difference spectrum of envelope information waves is also derived, by which the feature spectrum can be extracted clearly and machine faults can be effectively differentiated. This paper also compares the proposed method with the conventional Hilbert-transform-based envelope detection and with a wavelet analysis technique. Practical examples of diagnosis for a rolling element bearing used in a diesel engine are provided to verify the effectiveness of the proposed method. The verification results show that the bearing faults that typically occur in rolling element bearings, such as outer-race, inner-race, and roller defects, can be effectively identified by the proposed method, while these bearing faults are difficult to detect using either of the other techniques it was compared to. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Japan)

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9 pages, 129 KiB

Open AccessArticle

Electrochemical Direct Determination of Catecholamines for the Early Detection of Neurodegenerative Diseases

by Antonella Curulli

Institute of Nanostructured Materials (ISMN) CNR Division 2, via del Castro Laurenziano 7, 00161 Rome, Italy

Sensors 2009, 9(4), 2437-2445; https://doi.org/10.3390/s90402437 - 7 Apr 2009

Cited by 15 | Viewed by 11800

Abstract

Smart (Nano) materials with biosensing functions posses enormous potential in development of new generation of stable biosensors, chemical sensors, and actuators. Recently, there is a considerable interest in using TiO₂ nanostructured materials as a film-forming material since they have high surface area, [...] Read more.

Smart (Nano) materials with biosensing functions posses enormous potential in development of new generation of stable biosensors, chemical sensors, and actuators. Recently, there is a considerable interest in using TiO₂ nanostructured materials as a film-forming material since they have high surface area, optical transparency, high bio-compatibility, and relatively good conductivity. In this work, TiO₂ nanostructured films were used as nanoporous electrodes to study the electron transfer mechanisms of dopamine. epinephrine and norepinephrine, in order to develop a new generation of chemical sensors. The interesting results obtained are described herein and the analytical characterization of these neurotransmitter sensors is reported. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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15 pages, 356 KiB

Open AccessArticle

Energy-efficient Area Coverage by Sensors with Adjustable Ranges

by Vyacheslav Zalyubovskiy¹, Adil Erzin¹, Sergey Astrakov² and Hyunseung Choo^3,*

¹ Sobolev Institute of Mathematics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia

² Russian State University of Trade and Economics, Kemerovo Branch, Kemerovo, Russia

³ School of Information and Communication Engineering, Sungkyunkwan University, Suwon, Korea

Sensors 2009, 9(4), 2446-2460; https://doi.org/10.3390/s90402446 - 8 Apr 2009

Cited by 55 | Viewed by 14024

Abstract

In wireless sensor networks, density control is an important technique for prolonging a network's lifetime. To reduce the overall energy consumption, it is desirable to minimize the overlapping sensing area of the sensor nodes. In this paper, we study the problem of energy-efficient [...] Read more.

In wireless sensor networks, density control is an important technique for prolonging a network's lifetime. To reduce the overall energy consumption, it is desirable to minimize the overlapping sensing area of the sensor nodes. In this paper, we study the problem of energy-efficient area coverage by the regular placement of sensors with adjustable sensing and communication ranges. We suggest a more accurate method to estimate efficiency than those currently used for coverage by sensors with adjustable ranges, and propose new density control models that considerably improve coverage using sensors with two sensing ranges. Calculations and extensive simulation show that the new models outperform existing ones in terms of various performance metrics. Full article

(This article belongs to the Section Chemical Sensors)

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Graphical abstract

9 pages, 237 KiB

Open AccessCommunication

Data Compression by Shape Compensation for Mobile Video Sensors

by Ben-Shung Chow

Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, 80424, ROC

Sensors 2009, 9(4), 2461-2469; https://doi.org/10.3390/s90402461 - 9 Apr 2009

Cited by 2 | Viewed by 10929

Abstract

Most security systems, with their transmission bandwidth and computing power both being sufficient, emphasize their automatic recognition techniques. However, in some situations such as baby monitors and intruder avoidance by mobile sensors, the decision function sometimes can be shifted to the concerned human [...] Read more.

Most security systems, with their transmission bandwidth and computing power both being sufficient, emphasize their automatic recognition techniques. However, in some situations such as baby monitors and intruder avoidance by mobile sensors, the decision function sometimes can be shifted to the concerned human to reduce the transmission and computation cost. We therefore propose a binary video compression method in low resolution to achieve a low cost mobile video communication for inexpensive camera sensors. Shape compensation as proposed in this communication successfully replaces the standard Discrete Cosine Transformation (DCT) after motion compensation. Full article

(This article belongs to the Section Chemical Sensors)

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8 pages, 270 KiB

Open AccessArticle

Fabrication of Submicron Beams with Galvanic Etch Stop for Si in TMAH

by Rong Lu^{1, 2}, Yanhong Wu¹, Haitao Cheng^1,2, Heng Yang^1,*

, Xinxin Li¹ and Yuelin Wang¹

¹ State Key Laboratory of Transducer Technology , Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Yishan Road 800, Shanghai, P.R. China

² Graduate School of the Chinese Academy of Sciences, Beijing 100039, P.R. China

Sensors 2009, 9(4), 2470-2477; https://doi.org/10.3390/s90402470 - 9 Apr 2009

Cited by 3 | Viewed by 14756

Abstract

A novel method has been developed to fabricate submicron beams with galvanic etch stop for Si in TMAH. The different Au:Si area ratios before and after the release of the beams are used to trigger the galvanic etch stop to fabricate submicron single [...] Read more.

A novel method has been developed to fabricate submicron beams with galvanic etch stop for Si in TMAH. The different Au:Si area ratios before and after the release of the beams are used to trigger the galvanic etch stop to fabricate submicron single crystal Si beams in standard Si wafers. Before the beams are released from the substrate, the Au electrodes are connected to the substrate electrically. The Au:Si area ratios are much smaller than the threshold value. TMAH etches the Si wafers. After the beams are fully released, they are mechanically supported by the Au wires, which also serve as the galvanic etch stop cathodes. The Au:Si area ratios are much larger than the threshold value. The beams are protected by galvanic etch stop. The thicknesses of the beams are determined by shallow dry etching before TMAH etching. A 530 nm thick beam was fabricated in standard (111) wafers. Experiments showed that the beam thicknesses did not change with over etching, even if the SiO₂ layers on the surface of the beams were stripped. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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Graphical abstract

13 pages, 450 KiB

Open AccessArticle

Fabrication and Characterization of a Ruthenium Nitride Membrane for Electrochemical pH Sensors

by Yi-Hung Liao^{1, 2} and Jung-Chuan Chou^{1, 3,*}

¹ Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology / 123, 3 sec. University, Douliou, Yunlin, Taiwan R.O.C.

² Department of Information Management, Transworld of Institute of Technology / 1221, Jen-Nang Rd., Chia-Tong Li, Douliou, Yunlin, Taiwan R.O.C.

³ Graduate School of Electronic Engineering, National Yunlin University of Science and Technology/ 123, 3 sec. University, Douliou, Yunlin, Taiwan R.O.C.

Sensors 2009, 9(4), 2478-2490; https://doi.org/10.3390/s90402478 - 9 Apr 2009

Cited by 39 | Viewed by 14292

Abstract

ThepH sensing and nonideal characteristics of a ruthenium nitride (RuN) sensing membrane pH sensor were investigated. RuN thin films were deposited from a 99.9% ruthenium target on p-type silicon substrates using radio frequency (r.f.) sputtering with N₂ gas. Subsequently, the nanometric structure [...] Read more.

ThepH sensing and nonideal characteristics of a ruthenium nitride (RuN) sensing membrane pH sensor were investigated. RuN thin films were deposited from a 99.9% ruthenium target on p-type silicon substrates using radio frequency (r.f.) sputtering with N₂ gas. Subsequently, the nanometric structure and surface morphology of RuN thin films were determined. The sensitivity of the RuN sensing membrane pH sensor was 58.03 mV/pH, obtained from I_D-V_G curves with a current-voltage (I-V) measurement system in standard buffer solutions from pH 1 to pH 13 at room temperature (25 °C). Moreover, the nonideal characteristics of the RuN sensing membrane, such as temperature coefficient, drift with light influence, drift rate and hysteresis width, etc. were also investigated. Finally, the sensing characteristics of the RuN membrane were compared with titanium nitride (TiN), aluminum nitride (AlN) and silicon nitride (Si₃N₄) membranes. Full article

(This article belongs to the Section Chemical Sensors)

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7 pages, 434 KiB

Open AccessArticle

Chopper Stabilized Low Resistance Comparator

by Radojle M. Radetic¹ and Dragan R. Milivojevic^2,*

¹ Serbian Transmission System / Nade Dimic 40, 19210 Bor, Serbia

² Mining and Metallurgy Institute, Department of Informatics / Zeleni Bulevar 35, 19210 Bor, Serbia

Sensors 2009, 9(4), 2491-2497; https://doi.org/10.3390/s90402491 - 9 Apr 2009

Cited by 4 | Viewed by 11926

Abstract

The paper describes an improvement of the chopper method for elimination of parasitic voltages in a low resistance comparison and measurement procedure. The basic circuit diagram along with a short description of the working principle are presented and the appropriate low resistance comparator [...] Read more.

The paper describes an improvement of the chopper method for elimination of parasitic voltages in a low resistance comparison and measurement procedure. The basic circuit diagram along with a short description of the working principle are presented and the appropriate low resistance comparator prototype was designed and realized. Preliminary examinations confirm the possibility of measuring extremely low voltages. Very high accuracy in resistance comparison and measurement is achieved (0.08 ppm for 1,000 attempts). Some special critical features in the design are discussed and solutions for overcoming the problems are described. Full article

(This article belongs to the Section Chemical Sensors)

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13 pages, 319 KiB

Open AccessArticle

A Small-Displacement Sensor Using Total Internal Reflection Theory and Surface Plasmon Resonance Technology for Heterodyne Interferometry

by Shinn-Fwu Wang

Department of Electronic Engineering, Ching Yun University, No.229, Chien-Hsin Rd., Jhongli City, Taoyuan, 320, Taiwan, ROC

Sensors 2009, 9(4), 2498-2510; https://doi.org/10.3390/s90402498 - 14 Apr 2009

Cited by 17 | Viewed by 13203

Abstract

A small-displacement sensor based on total-internal reflection theory and surface plasmon resonance technology is proposed for use in heterodyne interferometry. A small displacement can be obtained simply by measuring the variation in phase difference between s- and p-polarization states with the small-displacement sensor. [...] Read more.

A small-displacement sensor based on total-internal reflection theory and surface plasmon resonance technology is proposed for use in heterodyne interferometry. A small displacement can be obtained simply by measuring the variation in phase difference between s- and p-polarization states with the small-displacement sensor. The theoretical displacement resolution of the small-displacement sensor can reach 0.45 nm. The sensor has some additional advantages, e.g., a simple optical setup, high resolution, high sensitivity and rapid measurement. Its feasibility is also demonstrated. Full article

(This article belongs to the Section Chemical Sensors)

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13 pages, 353 KiB

Open AccessArticle

Biotelemetric Monitoring of Brain Neurochemistry in Conscious Rats Using Microsensors and Biosensors

by Giammario Calia¹, Gaia Rocchitta¹

, Rossana Migheli¹, Giulia Puggioni¹, Ylenia Spissu¹

, Gianfranco Bazzu¹, Vittorio Mazzarello², John P. Lowry³, Robert D. O’Neill⁴, Maria S. Desole¹ and Pier A. Serra^1,*

¹ Department of Neuroscience, Medical School, University of Sassari, Viale S. Pietro 43/b, 07100 Sassari, Italy

² Department of Biomedical Sciences, Medical School, University of Sassari, Viale S. Pietro 43/b, 07100 Sassari, Italy

³ of Chemistry, National University of Ireland, Maynooth, Co. Kildare, Ireland

⁴ CD School of Chemistry and Chemical Biology, University College Dublin, Belﬁeld, Dublin 4, Ireland

Sensors 2009, 9(4), 2511-2523; https://doi.org/10.3390/s90402511 - 14 Apr 2009

Cited by 44 | Viewed by 16827

Abstract

In this study we present the real-time monitoring of three key brain neurochemical species in conscious rats using implantable amperometric electrodes interfaced to a biotelemetric device. The new system, derived from a previous design, was coupled with carbon-based microsensors and a platinum-based biosensor [...] Read more.

In this study we present the real-time monitoring of three key brain neurochemical species in conscious rats using implantable amperometric electrodes interfaced to a biotelemetric device. The new system, derived from a previous design, was coupled with carbon-based microsensors and a platinum-based biosensor for the detection of ascorbic acid (AA), O₂ and glucose in the striatum of untethered, freely-moving rats. The miniaturized device consisted of a single-supply sensor driver, a current-to-voltage converter, a microcontroller and a miniaturized data transmitter. The redox currents were digitized to digital values by means of an analog-to-digital converter integrated in a peripheral interface controller (PIC), and sent to a personal computer by means of a miniaturized AM transmitter. The electronics were calibrated and tested in vitro under different experimental conditions and exhibited high stability, low power consumption and good linear response in the nanoampere current range. The in-vivo results confirmed previously published observations on striatal AA, oxygen and glucose dynamics recorded in tethered rats. This approach, based on simple and inexpensive components, could be used as a rapid and reliable model for studying the effects of different drugs on brain neurochemical systems Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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14 pages, 815 KiB

Open AccessArticle

An Adaptable, Portable Microarray Reader for Biodetection

by Deanna L. Thompson¹, Francesca Pearson^{2, †}, Cynthia Thomas², Rupa Rao^{1, †}, Dennis Matthews^{1, 3}, Joanna S. Albala^{1, †}, Sebastian Wachsmann-Hogiu^{1, 4,*} and Matthew A. Coleman^{1, 2, 5,*}

¹ NSF – Center for Biophotonics Science and Technology, University of California Davis / 2700 Stockton Blvd. Sacramento CA 95817, USA

² Lawrence Livermore National Laboratory / 7000 East Ave., Livermore, CA 94550, USA

³ University of California, Davis Medical Center, Department of Neurological Surgery / 860 Y St., Suite 3740 | Sacramento, CA 95817, USA

⁴ University of California, Davis Medical Center, Department of Pathology and Laboratory Medicine / 4400 V Street | Sacramento, CA 95817, USA

⁵ University of California, Davis Medical Center, Department of Radiation Oncology / 4501 X Street, Suite G-140 | Sacramento, CA 95817, USA

^† Current affil.: Microchip Biotechnologies, Inc., 6693 Sierra Lane, Suite F., Dublin, CA 94568, USA (F.P.); Abbott Laboratories, 5440 Patrick Henry Dr., Santa Clara, CA 95054, USA (R.R.); Univ. of the Pacific, 3601 Pacific Avenue, Stockton, CA 95211, USA

Sensors 2009, 9(4), 2524-2537; https://doi.org/10.3390/s90402524 - 14 Apr 2009

Cited by 12 | Viewed by 14909

Abstract

We have developed an inexpensive portable microarray reader that can be applied to standard microscope slide-based arrays and other array formats printed on chemically modified surfaces. Measuring only 19 cm in length, the imaging device is portable and may be applicable to both [...] Read more.

We have developed an inexpensive portable microarray reader that can be applied to standard microscope slide-based arrays and other array formats printed on chemically modified surfaces. Measuring only 19 cm in length, the imaging device is portable and may be applicable to both triage and clinical settings. For multiplexing and adaptability purposes, it can be modified to work with multiple excitation/emission wavelengths. Our device is shown to be comparable to a commercial laser scanner when detecting both streptavidin-biotin and antibody interactions. This paper presents the development and characterization of a handheld microarray imager and directly compares it with a commercial scanner. Full article

(This article belongs to the Section Biosensors)

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17 pages, 223 KiB

Open AccessReview

Advances in Microbial Biofilm Prevention on Indwelling Medical Devices with Emphasis on Usage of Acoustic Energy

by Naama Dror¹, Mathilda Mandel², Zadik Hazan³ and Gad Lavie^1,*

¹ Department of Cellular and Developmental Biology, Tel-Aviv University, Tel-Aviv, Israel

² Blood Center, Sheba Medical Center, Tel-Hashomer, Israel

³ Regenera Pharma Ltd., Rehovot, Israel

Sensors 2009, 9(4), 2538-2554; https://doi.org/10.3390/s90402538 - 14 Apr 2009

Cited by 51 | Viewed by 18823

Abstract

Microbial biofilms are a major impediment to the use of indwelling medical devices, generating device-related infections with high morbidity and mortality. Major efforts directed towards preventing and eradicating the biofilm problem face difficulties because biofilms protect themselves very effectively by producing a polysaccharide [...] Read more.

Microbial biofilms are a major impediment to the use of indwelling medical devices, generating device-related infections with high morbidity and mortality. Major efforts directed towards preventing and eradicating the biofilm problem face difficulties because biofilms protect themselves very effectively by producing a polysaccharide coating, reducing biofilm sensitivity to antimicrobial agents. Techniques applied to combating biofilms have been primarily chemical. These have met with partial and limited success rates, leading to current trends of eradicating biofilms through physico-mechanical strategies. Here we review the different approaches that have been developed to control biofilm formation and removal, focusing on the utilization of acoustic energy to achieve these objectives. Full article

(This article belongs to the Special Issue Pathogen Sensors)

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19 pages, 1519 KiB

Open AccessArticle

Parallel Processing Method for Airborne Laser Scanning Data Using a PC Cluster and a Virtual Grid

by Soo Hee Han¹, Joon Heo^1,*, Hong Gyoo Sohn¹ and Kiyun Yu²

¹ School of Civil and Environmental Engineering, Yonsei University / 134 Sinchon-dong Seodaemun-gu, Seoul 120-749, Korea

² Department of Civil, Urban and GeoSystem Engineering, Seoul National University / 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea

Sensors 2009, 9(4), 2555-2573; https://doi.org/10.3390/s90402555 - 14 Apr 2009

Cited by 32 | Viewed by 19546

Abstract

In this study, a parallel processing method using a PC cluster and a virtual grid is proposed for the fast processing of enormous amounts of airborne laser scanning (ALS) data. The method creates a raster digital surface model (DSM) by interpolating point data [...] Read more.

In this study, a parallel processing method using a PC cluster and a virtual grid is proposed for the fast processing of enormous amounts of airborne laser scanning (ALS) data. The method creates a raster digital surface model (DSM) by interpolating point data with inverse distance weighting (IDW), and produces a digital terrain model (DTM) by local minimum filtering of the DSM. To make a consistent comparison of performance between sequential and parallel processing approaches, the means of dealing with boundary data and of selecting interpolation centers were controlled for each processing node in parallel approach. To test the speedup, efficiency and linearity of the proposed algorithm, actual ALS data up to 134 million points were processed with a PC cluster consisting of one master node and eight slave nodes. The results showed that parallel processing provides better performance when the computational overhead, the number of processors, and the data size become large. It was verified that the proposed algorithm is a linear time operation and that the products obtained by parallel processing are identical to those produced by sequential processing. Full article

(This article belongs to the Section Remote Sensors)

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12 pages, 305 KiB

Open AccessArticle

Non-Contact Detection of Breathing Using a Microwave Sensor

by Devis Dei^1,*, Gilberto Grazzini¹, Guido Luzi¹, Massimiliano Pieraccini¹

, Carlo Atzeni¹, Sergio Boncinelli², Gianna Camiciottoli³, Walter Castellani³, Massimo Marsili² and Juri Lo Dico²

¹ Department of Electronics and Telecommunications, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy

² Department of Medical and Surgical Critical Area, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy

³ Unit of Respiratory Physiopathology, University of Florence, Viale Morgagni 85, 50134 Firenze, Italy

Sensors 2009, 9(4), 2574-2585; https://doi.org/10.3390/s90402574 - 14 Apr 2009

Cited by 54 | Viewed by 19085

Abstract

In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its [...] Read more.

In this paper the use of a continuous-wave microwave sensor as a non-contact tool for quantitative measurement of respiratory tidal volume has been evaluated by experimentation in seventeen healthy volunteers. The sensor working principle is reported and several causes that can affect its response are analyzed. A suitable data processing has been devised able to reject the majority of breath measurements taken under non suitable conditions. Furthermore, a relationship between microwave sensor measurements and volume inspired and expired at quiet breathing (tidal volume) has been found. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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Graphical abstract

25 pages, 2290 KiB

Open AccessArticle

An Artificial Neural Network Embedded Position and Orientation Determination Algorithm for Low Cost MEMS INS/GPS Integrated Sensors

by Kai-Wei Chiang, Hsiu-Wen Chang^*

, Chia-Yuan Li and Yun-Wen Huang

Department of Geomatics, National Cheng-Kung University / No.1, Ta-Hsueh Road, Tainan 701, Taiwan

Sensors 2009, 9(4), 2586-2610; https://doi.org/10.3390/s90402586 - 15 Apr 2009

Cited by 41 | Viewed by 17297

Abstract

Digital mobile mapping, which integrates digital imaging with direct geo-referencing, has developed rapidly over the past fifteen years. Direct geo-referencing is the determination of the time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose [...] Read more.

Digital mobile mapping, which integrates digital imaging with direct geo-referencing, has developed rapidly over the past fifteen years. Direct geo-referencing is the determination of the time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning using Global Positioning System (GPS) and Inertial Navigation System (INS) using an Inertial Measurement Unit (IMU). They are usually integrated in such a way that the GPS receiver is the main position sensor, while the IMU is the main orientation sensor. The Kalman Filter (KF) is considered as the optimal estimation tool for real-time INS/GPS integrated kinematic position and orientation determination. An intelligent hybrid scheme consisting of an Artificial Neural Network (ANN) and KF has been proposed to overcome the limitations of KF and to improve the performance of the INS/GPS integrated system in previous studies. However, the accuracy requirements of general mobile mapping applications can’t be achieved easily, even by the use of the ANN-KF scheme. Therefore, this study proposes an intelligent position and orientation determination scheme that embeds ANN with conventional Rauch-Tung-Striebel (RTS) smoother to improve the overall accuracy of a MEMS INS/GPS integrated system in post-mission mode. By combining the Micro Electro Mechanical Systems (MEMS) INS/GPS integrated system and the intelligent ANN-RTS smoother scheme proposed in this study, a cheaper but still reasonably accurate position and orientation determination scheme can be anticipated. Full article

(This article belongs to the Special Issue Neural Networks and Sensors)

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10 pages, 237 KiB

Open AccessArticle

A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls

by Min Du, Xiongying Ye^*, Kang Wu and Zhaoying Zhou

State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, P.R. China

Sensors 2009, 9(4), 2611-2620; https://doi.org/10.3390/s90402611 - 15 Apr 2009

Cited by 36 | Viewed by 16861

Abstract

In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. [...] Read more.

In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ~490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can also be adjusted by using steel balls with different diameters or changing the number of balls. Nevertheless, the micro pump can also work in high speed mode. A high back pressure up to 10 kPa was achieved at 500 rpm using a high speed DC motor, and an utmost flow rate up to 5 mL/min was reached. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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26 pages, 1983 KiB

Open AccessArticle

Automatic Registration of Terrestrial Laser Scanning Point Clouds using Panoramic Reflectance Images

by Zhizhong Kang^{1, 2,*}, Jonathan Li³

, Liqiang Zhang⁴, Qile Zhao⁵ and Sisi Zlatanova⁶

¹ Faculty of Aerospace Engineering, Delft University of Technology / Kluyverweg 1, 2629 HS Delft, The Netherlands

² School of Land Science and Technology, China University of Geosciences / Beijing 100083, China

³ Department of Geography and Environmental Management, University of Waterloo / Waterloo, Ontario N2L 3G1, Canada

⁴ Research Centre for Remote Sensing and GIS, School of Geography, Beijing Normal University / Beijing 100875, P.R. China

⁵ GNSS Research Centre, Wuhan University / Wuhan 430079, Hubei Province, P.R. China

⁶ OTB Research Institute for Housing, Urban and Mobility Studies, Delft University of Technology / Jaffalaan 9, 2628 BX Delft, The Netherlands

Sensors 2009, 9(4), 2621-2646; https://doi.org/10.3390/s90402621 - 15 Apr 2009

Cited by 96 | Viewed by 17707

Abstract

This paper presents a new approach to the automatic registration of terrestrial laser scanning (TLS) point clouds using panoramic reflectance images. The approach follows a two-step procedure that includes both pair-wise registration and global registration. The pair-wise registration consists of image matching (pixel-to-pixel [...] Read more.

This paper presents a new approach to the automatic registration of terrestrial laser scanning (TLS) point clouds using panoramic reflectance images. The approach follows a two-step procedure that includes both pair-wise registration and global registration. The pair-wise registration consists of image matching (pixel-to-pixel correspondence) and point cloud registration (point-to-point correspondence), as the correspondence between the image and the point cloud (pixel-to-point) is inherent to the reflectance images. False correspondences are removed by a geometric invariance check. The pixel-to-point correspondence and the computation of the rigid transformation parameters (RTPs) are integrated into an iterative process that allows for the pair-wise registration to be optimised. The global registration of all point clouds is obtained by a bundle adjustment using a circular self-closure constraint. Our approach is tested with both indoor and outdoor scenes acquired by a FARO LS 880 laser scanner with an angular resolution of 0.036° and 0.045°, respectively. The results show that the pair-wise and global registration accuracies are of millimetre and centimetre orders, respectively, and that the process is fully automatic and converges quickly. Full article

(This article belongs to the Special Issue LiDAR for 3D City Modeling)

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14 pages, 2898 KiB

Open AccessCommunication

Development of a Green Roof Environmental Monitoring and Meteorological Network in New York City

by Stuart R. Gaffin^1,*, Reza Khanbilvardi² and Cynthia Rosenzweig¹

¹ Center for Climate Systems Research, Columbia University, New York, NY 10025, USA

² Department of Civil Engineering & Earth and Environmental Sciences, City College of New York, New York, NY, USA

Sensors 2009, 9(4), 2647-2660; https://doi.org/10.3390/s90402647 - 15 Apr 2009

Cited by 48 | Viewed by 20618

Abstract

Green roofs (with plant cover) are gaining attention in the United States as a versatile new environmental mitigation technology. Interest in data on the environmental performance of these systems is growing, particularly with respect to urban heat island mitigation and stormwater runoff control. [...] Read more.

Green roofs (with plant cover) are gaining attention in the United States as a versatile new environmental mitigation technology. Interest in data on the environmental performance of these systems is growing, particularly with respect to urban heat island mitigation and stormwater runoff control. We are deploying research stations on a diverse array of green roofs within the New York City area, affording a new opportunity to monitor urban environmental conditions at small scales. We show some green roof systems being monitored, describe the sensor selection employed to study energy balance, and show samples of selected data. These roofs should be superior to other urban rooftops as sites for meteorological stations. Full article

(This article belongs to the Section Remote Sensors)

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21 pages, 119 KiB

Open AccessArticle

Discovery Mechanisms for the Sensor Web

by Simon Jirka^*, Arne Bröring and Christoph Stasch

Westfälische Wilhelms-Universität, Institute for Geoinformatics, Weseler Straße 253, 48151 Münster, Germany

Sensors 2009, 9(4), 2661-2681; https://doi.org/10.3390/s90402661 - 16 Apr 2009

Cited by 91 | Viewed by 16320

Abstract

This paper addresses the discovery of sensors within the OGC Sensor Web Enablement framework. Whereas services like the OGC Web Map Service or Web Coverage Service are already well supported through catalogue services, the field of sensor networks and the according discovery mechanisms [...] Read more.

This paper addresses the discovery of sensors within the OGC Sensor Web Enablement framework. Whereas services like the OGC Web Map Service or Web Coverage Service are already well supported through catalogue services, the field of sensor networks and the according discovery mechanisms is still a challenge. The focus within this article will be on the use of existing OGC Sensor Web components for realizing a discovery solution. After discussing the requirements for a Sensor Web discovery mechanism, an approach will be presented that was developed within the EU funded project “OSIRIS”. This solution offers mechanisms to search for sensors, exploit basic semantic relationships, harvest sensor metadata and integrate sensor discovery into already existing catalogues. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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15 pages, 802 KiB

Open AccessReview

Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation

by Anna Paola Caricato¹, Armando Luches^1,* and Roberto Rella²

¹ University of Salento, Department of Physics, Via Arnesano, 73100 Lecce, Italy

² Istituto per la Microelettronica ed i Microsistemi (IMM) CNR, Via Monteroni, 73100 Lecce, Italy

Sensors 2009, 9(4), 2682-2696; https://doi.org/10.3390/s90402682 - 16 Apr 2009

Cited by 69 | Viewed by 16873

Abstract

The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO₂, SnO₂) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the [...] Read more.

The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO₂, SnO₂) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al₂O₃ substrates. A rather uniform distribution of TiO₂ nanoparticles with an average size of about 10 nm and of SnO₂ nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG) inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit) towards ethanol and acetone are presented. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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9 pages, 297 KiB

Open AccessArticle

Quantum Cascade Laser-Based Photoacoustic Sensor for Trace Detection of Formaldehyde Gas

by Angela Elia^*, Cinzia Di Franco, Vincenzo Spagnolo, Pietro Mario Lugarà^* and Gaetano Scamarcio

Dipartimento Interateneo di Fisica “M. Merlin”, Università and Politecnico of Bari, and Laboratorio Regionale CNR-INFM “LIT3”, Bari, I-70126, Italy

Sensors 2009, 9(4), 2697-2705; https://doi.org/10.3390/s90402697 - 16 Apr 2009

Cited by 41 | Viewed by 14422

Abstract

We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH₂O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 mm. A resonant photoacoustic cell, equipped with four electret microphones, is excited [...] Read more.

We report on the development of a photoacoustic sensor for the detection of formaldehyde (CH₂O) using a thermoelectrically cooled distributed-feedback quantum cascade laser operating in pulsed mode at 5.6 mm. A resonant photoacoustic cell, equipped with four electret microphones, is excited in its first longitudinal mode at 1,380 Hz. The absorption line at 1,778.9 cm^-1 is selected for CH₂O detection. A detection limit of 150 parts per billion in volume in nitrogen is achieved using a 10 seconds time constant and 4 mW laser power. Measurements in ambient air will require water vapour filters. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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13 pages, 481 KiB

Open AccessArticle

Comparison between Deflection and Vibration Characteristics of Rectangular and Trapezoidal profile Microcantilevers

by Mohd. Zahid Ansari, Chongdu Cho^*, Jooyong Kim and Booun Bang

Department of Mechanical Engineering, Inha University, 253 Yonghyun-dong, Nam-Ku, Incheon, 402-751 Republic of Korea

Sensors 2009, 9(4), 2706-2718; https://doi.org/10.3390/s90402706 - 16 Apr 2009

Cited by 39 | Viewed by 13123

Abstract

Arrays of microcantilevers are increasingly being used as physical, biological, and chemical sensors in various applications. To improve the sensitivity of microcantilever sensors, this study analyses and compares the deflection and vibration characteristics of rectangular and trapezoidal profile microcantilevers. Three models of each [...] Read more.

Arrays of microcantilevers are increasingly being used as physical, biological, and chemical sensors in various applications. To improve the sensitivity of microcantilever sensors, this study analyses and compares the deflection and vibration characteristics of rectangular and trapezoidal profile microcantilevers. Three models of each profile are investigated. The cantilevers are analyzed for maximum deflection, fundamental resonant frequency and maximum stress. The surface stress is modelled as in-plane tensile force applied on the top edge of the microcantilevers. A commercial finite element analysis software ANSYS is used to analyze the designs. Results show paddled trapezoidal profile microcantilevers have better sensitivity. Full article

(This article belongs to the Section Biosensors)

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27 pages, 468 KiB

Open AccessReview

Retrieving Leaf Area Index (LAI) Using Remote Sensing: Theories, Methods and Sensors

by Guang Zheng and L. Monika Moskal^*

Remote Sensing and Geospatial Analysis Laboratory and Precision Forestry Cooperative, College of Forest Resources, University of Washington, Box 352100, Seattle, Washington, 98195-2100, USA

Sensors 2009, 9(4), 2719-2745; https://doi.org/10.3390/s90402719 - 17 Apr 2009

Cited by 481 | Viewed by 46196

Abstract

The ability to accurately and rapidly acquire leaf area index (LAI) is an indispensable component of process-based ecological research facilitating the understanding of gas-vegetation exchange phenomenon at an array of spatial scales from the leaf to the landscape. However, LAI is difficult to [...] Read more.

The ability to accurately and rapidly acquire leaf area index (LAI) is an indispensable component of process-based ecological research facilitating the understanding of gas-vegetation exchange phenomenon at an array of spatial scales from the leaf to the landscape. However, LAI is difficult to directly acquire for large spatial extents due to its time consuming and work intensive nature. Such efforts have been significantly improved by the emergence of optical and active remote sensing techniques. This paper reviews the definitions and theories of LAI measurement with respect to direct and indirect methods. Then, the methodologies for LAI retrieval with regard to the characteristics of a range of remotely sensed datasets are discussed. Remote sensing indirect methods are subdivided into two categories of passive and active remote sensing, which are further categorized as terrestrial, aerial and satellite-born platforms. Due to a wide variety in spatial resolution of remotely sensed data and the requirements of ecological modeling, the scaling issue of LAI is discussed and special consideration is given to extrapolation of measurement to landscape and regional levels. Full article

(This article belongs to the Section Remote Sensors)

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14 pages, 671 KiB

Open AccessArticle

Orientation Effects in Ballistic High-Strained P-type Si Nanowire FETs

by Jia-Hong Zhang^{1, 2}, Qing-An Huang^1,*

, Hong Yu¹ and Shuang-Ying Lei^1,*

¹ Key Laboratory of MEMS of Ministry of Education, Southeast University, 2 Sipailou, Nanjing, Jiangsu, People’s Republic of China

² College of Electronic & Information Engineering, Nanjing University of Information Science & Technology, 219 Ning-Lu Road, Nanjing, Jiangsu, People’s Republic of China

Sensors 2009, 9(4), 2746-2759; https://doi.org/10.3390/s90402746 - 17 Apr 2009

Cited by 10 | Viewed by 15320

Abstract

In order to design and optimize high-sensitivity silicon nanowire-field-effect transistor (SiNW FET) pressure sensors, this paper investigates the effects of channel orientations and the uniaxial stress on the ballistic hole transport properties of a strongly quantized SiNW FET placed near the high stress [...] Read more.

In order to design and optimize high-sensitivity silicon nanowire-field-effect transistor (SiNW FET) pressure sensors, this paper investigates the effects of channel orientations and the uniaxial stress on the ballistic hole transport properties of a strongly quantized SiNW FET placed near the high stress regions of the pressure sensors. A discrete stress-dependent six-band k.p method is used for subband structure calculation, coupled to a two-dimensional Poisson solver for electrostatics. A semi-classical ballistic FET model is then used to evaluate the ballistic current-voltage characteristics of SiNW FETs with and without strain. Our results presented here indicate that [110] is the optimum orientation for the p-type SiNW FETs and sensors. For the ultra-scaled 2.2 nm square SiNW, due to the limit of strong quantum confinement, the effect of the uniaxial stress on the magnitude of ballistic drive current is too small to be considered, except for the [100] orientation. However, for larger 5 nm square SiNW transistors with various transport orientations, the uniaxial tensile stress obviously alters the ballistic performance, while the uniaxial compressive stress slightly changes the ballistic hole current. Furthermore, the competition of injection velocity and carrier density related to the effective hole masses is found to play a critical role in determining the performance of the nanotransistors. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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20 pages, 284 KiB

Open AccessArticle

Adapting Mobile Beacon-Assisted Localization in Wireless Sensor Networks

by Guodong Teng^*, Kougen Zheng and Wei Dong

College of Computer Science, Zhejiang University, Hangzhou 310027, P.R. China

Sensors 2009, 9(4), 2760-2779; https://doi.org/10.3390/s90402760 - 20 Apr 2009

Cited by 27 | Viewed by 16460

Abstract

The ability to automatically locate sensor nodes is essential in many Wireless Sensor Network (WSN) applications. To reduce the number of beacons, many mobile-assisted approaches have been proposed. Current mobile-assisted approaches for localization require special hardware or belong to centralized localization algorithms involving [...] Read more.

The ability to automatically locate sensor nodes is essential in many Wireless Sensor Network (WSN) applications. To reduce the number of beacons, many mobile-assisted approaches have been proposed. Current mobile-assisted approaches for localization require special hardware or belong to centralized localization algorithms involving some deterministic approaches due to the fact that they explicitly consider the impreciseness of location estimates. In this paper, we first propose a range-free, distributed and probabilistic Mobile Beacon-assisted Localization (MBL) approach for static WSNs. Then, we propose another approach based on MBL, called Adapting MBL (A-MBL), to increase the efficiency and accuracy of MBL by adapting the size of sample sets and the parameter of the dynamic model during the estimation process. Evaluation results show that the accuracy of MBL and A-MBL outperform both Mobile and Static sensor network Localization (MSL) and Arrival and Departure Overlap (ADO) when both of them use only a single mobile beacon for localization in static WSNs. Full article

(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)

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17 pages, 902 KiB

Open AccessArticle

Use of Naturally Available Reference Targets to Calibrate Airborne Laser Scanning Intensity Data

by Ants Vain^*, Sanna Kaasalainen, Ulla Pyysalo, Anssi Krooks and Paula Litkey

Department of Remote Sensing and Photogrammetry, Finnish Geodetic Institute, Geodeetinrinne 2, 02431 Masala, Finland

Sensors 2009, 9(4), 2780-2796; https://doi.org/10.3390/s90402780 - 20 Apr 2009

Cited by 52 | Viewed by 14788

Abstract

We have studied the possibility of calibrating airborne laser scanning (ALS) intensity data, using land targets typically available in urban areas. For this purpose, a test area around Espoonlahti Harbor, Espoo, Finland, for which a long time series of ALS campaigns is available, [...] Read more.

We have studied the possibility of calibrating airborne laser scanning (ALS) intensity data, using land targets typically available in urban areas. For this purpose, a test area around Espoonlahti Harbor, Espoo, Finland, for which a long time series of ALS campaigns is available, was selected. Different target samples (beach sand, concrete, asphalt, different types of gravel) were collected and measured in the laboratory. Using tarps, which have certain backscattering properties, the natural samples were calibrated and studied, taking into account the atmospheric effect, incidence angle and flying height. Using data from different flights and altitudes, a time series for the natural samples was generated. Studying the stability of the samples, we could obtain information on the most ideal types of natural targets for ALS radiometric calibration. Using the selected natural samples as reference, the ALS points of typical land targets were calibrated again and examined. Results showed the need for more accurate ground reference data, before using natural samples in ALS intensity data calibration. Also, the NIR camera-based field system was used for collecting ground reference data. This system proved to be a good means for collecting in situ reference data, especially for targets with inhomogeneous surface reflection properties. Full article

(This article belongs to the Special Issue LiDAR for 3D City Modeling)

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12 pages, 1255 KiB

Open AccessArticle

A Novel Intra-body Sensor for Vaginal Temperature Monitoring

by Joel J. P. C. Rodrigues^1,*

, João Caldeira² and Binod Vaidya³

¹ Instituto de Telecomunicações, Department of Informatics, University of Beira Interior, Covilhã, 6200-001, Portugal

² University of Beira Interior, Department of Informatics, Covilhã-Portugal; Polytechnic Institute of Castelo Branco, EST, Castelo Branco, 6000-000, Portugal

³ Instituto de Telecomunicações, Covilhã, 6200-001, Portugal

Sensors 2009, 9(4), 2797-2808; https://doi.org/10.3390/s90402797 - 21 Apr 2009

Cited by 24 | Viewed by 20900

Abstract

Over the years some medical studies have tried to better understand the internal behavior of human beings. Many researchers in this domain have been striving to find relationships between intra-vaginal temperature and certain female health conditions, such as ovulation and fertile period since [...] Read more.

Over the years some medical studies have tried to better understand the internal behavior of human beings. Many researchers in this domain have been striving to find relationships between intra-vaginal temperature and certain female health conditions, such as ovulation and fertile period since woman’s intra-vaginal temperature is one of the body parameters most preferred in such studies. However, due to lack of a appropriate technology, medical research devoted to studying correlations of such body parameters with certain womans’ body phenomena could not obtain better results. This article presents the design and implementation of a novel intra-body sensor for acquisition and monitoring of intra-vaginal temperatures. This novel intra-body sensor provides data collection that is used for studying the relation between temperature variations and female health conditions, such as anticipation and monitoring of the ovulation period, detection of pregnancy contractions, preterm labor prevention, etc.. The motivation for this work focuses on the development of this new intra-body sensor that will represent a major step in medical technology. The novel sensor was tested and validated on hospitalized women as well as normal healthy women. Finally our medical team has attested to the accuracy, usability and performance of this novel intra-body sensor. Full article

(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)

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27 pages, 188 KiB

Open AccessReview

Root Zone Sensors for Irrigation Management in Intensive Agriculture

by Alberto Pardossi^1,*, Luca Incrocci¹, Giorgio Incrocci¹, Fernando Malorgio¹, Piero Battista², Laura Bacci², Bernardo Rapi², Paolo Marzialetti³, Jochen Hemming⁴ and Jos Balendonck⁴

¹ Dipartimento di Biologia delle Piante Agrarie, University of Pisa, Viale delle Piagge 23, 56124-I Pisa, Italy

² Istituto di Biometeorologia,Via Caproni 8, 50145 Firenze, Italy

³ Centro Sperimentale per il Vivaimo (CESPEVI), Via Ciliegiole 99, 51100 Pistoia, Italy

⁴ Wageningen University and Research Center, Greenhouse Horticulture, Droevendaalsesteeg 1, 6708 PB Wageningen, the Netherlands

Sensors 2009, 9(4), 2809-2835; https://doi.org/10.3390/s90402809 - 21 Apr 2009

Cited by 118 | Viewed by 27845

Abstract

Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of [...] Read more.

Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method). An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS), such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity) marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy) on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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15 pages, 803 KiB

Open AccessArticle

Anchor-Free Localization Method for Mobile Targets in Coal Mine Wireless Sensor Networks

by Zhongmin Pei^1,*, Zhidong Deng^1,*, Shuo Xu² and Xiao Xu¹

¹ State Key Laboratory of Intelligent Technology and Systems, Tsinghua National Laboratory for Information Science and Technology, Department of Computer Science and Technology, Tsinghua University, Beijing 100084, P.R. China

² Institute of Scientific and Technical Information of China, Beijing 100038, P.R. China

Sensors 2009, 9(4), 2836-2850; https://doi.org/10.3390/s90402836 - 21 Apr 2009

Cited by 45 | Viewed by 16791

Abstract

Severe natural conditions and complex terrain make it difficult to apply precise localization in underground mines. In this paper, an anchor-free localization method for mobile targets is proposed based on non-metric multi-dimensional scaling (Multi-dimensional Scaling: MDS) and rank sequence. Firstly, a coal mine [...] Read more.

Severe natural conditions and complex terrain make it difficult to apply precise localization in underground mines. In this paper, an anchor-free localization method for mobile targets is proposed based on non-metric multi-dimensional scaling (Multi-dimensional Scaling: MDS) and rank sequence. Firstly, a coal mine wireless sensor network is constructed in underground mines based on the ZigBee technology. Then a non-metric MDS algorithm is imported to estimate the reference nodes’ location. Finally, an improved sequence-based localization algorithm is presented to complete precise localization for mobile targets. The proposed method is tested through simulations with 100 nodes, outdoor experiments with 15 ZigBee physical nodes, and the experiments in the mine gas explosion laboratory with 12 ZigBee nodes. Experimental results show that our method has better localization accuracy and is more robust in underground mines. Full article

(This article belongs to the Special Issue Wireless Sensor Technologies and Applications)

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11 pages, 1153 KiB

Open AccessArticle

A Weld Defects Detection System Based on a Spectrometer

by Daniel Bebiano and Sadek C. A. Alfaro^*

Automation and Control Group, University of Brasilia, Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, Brasília – DF, CEP: 70910-900, Brazil

Sensors 2009, 9(4), 2851-2861; https://doi.org/10.3390/s90402851 - 21 Apr 2009

Cited by 14 | Viewed by 14004

Abstract

Improved product quality and production methods, and decreased production costs are important objectives of industries. Welding processes are part of this goal. There are many studies about monitoring and controlling welding process. This work presents a non-intrusive on-line monitoriment system and some algorithms [...] Read more.

Improved product quality and production methods, and decreased production costs are important objectives of industries. Welding processes are part of this goal. There are many studies about monitoring and controlling welding process. This work presents a non-intrusive on-line monitoriment system and some algorithms capable of detecting GTAW weld defects. Some experiments were made to simulate weld defects by disturbing the electric arc. The data comes from a spectrometer which captures perturbations on the electric arc by the radiation emission of chosen lines. Algorithms based on change detection methods are used to indicate the presence and localization of those defects. Full article

(This article belongs to the Section Chemical Sensors)

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Graphical abstract

22 pages, 369 KiB

Open AccessArticle

Wireless in-situ Sensor Network for Agriculture and Water Monitoring on a River Basin Scale in Southern Finland: Evaluation from a Data User’s Perspective

by Niina Kotamäki^1,*, Sirpa Thessler², Jari Koskiaho³, Asko O. Hannukkala⁴, Hanna Huitu², Timo Huttula¹, Jukka Havento² and Markku Järvenpää²

¹ Finnish Environment Institute, Jyväskylä Office / PO Box 35, FIN-40014 University of Jyväskylä / Finland

² MTT Agrifood Research Finland / Luutnantintie 13, 00410 Helsinki, Finland

³ Finnish Environment Institute / PO Box 140, FIN-00251 Helsinki, Finland

⁴ MTT Agrifood Research Finland, Plant Protection, R-building, 31600 Jokioinen, Finland

Sensors 2009, 9(4), 2862-2883; https://doi.org/10.3390/s90402862 - 21 Apr 2009

Cited by 84 | Viewed by 18616

Abstract

Sensor networks are increasingly being implemented for environmental monitoring and agriculture to provide spatially accurate and continuous environmental information and (near) real-time applications. These networks provide a large amount of data which poses challenges for ensuring data quality and extracting relevant information. In [...] Read more.

Sensor networks are increasingly being implemented for environmental monitoring and agriculture to provide spatially accurate and continuous environmental information and (near) real-time applications. These networks provide a large amount of data which poses challenges for ensuring data quality and extracting relevant information. In the present paper we describe a river basin scale wireless sensor network for agriculture and water monitoring. The network, called SoilWeather, is unique and the first of this type in Finland. The performance of the network is assessed from the user and maintainer perspectives, concentrating on data quality, network maintenance and applications. The results showed that the SoilWeather network has been functioning in a relatively reliable way, but also that the maintenance and data quality assurance by automatic algorithms and calibration samples requires a lot of effort, especially in continuous water monitoring over large areas. We see great benefits on sensor networks enabling continuous, real-time monitoring, while data quality control and maintenance efforts highlight the need for tight collaboration between sensor and sensor network owners to decrease costs and increase the quality of the sensor data in large scale applications. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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11 pages, 258 KiB

Open AccessArticle

On the Capability of Artificial Neural Networks to Compensate Nonlinearities in Wavelength Sensing

by Mohamed Lamine Hafiane^1,*, Zohir Dibi¹ and Otto Manck²

¹ Laboratoire d’Electronique Avancée, Département d’Electronique, Université de Batna, 05 avenue Chahid Boukhlouf 05000 Batna, Algeria

² Institut für Technische Informatik und Mikroelektronik, Technische Universität Berlin, Germany

Sensors 2009, 9(4), 2884-2894; https://doi.org/10.3390/s90402884 - 21 Apr 2009

Cited by 9 | Viewed by 13174

Abstract

An intelligent sensor for light wavelength readout, suitable for visible range optical applications, has been developed. Using buried triple photo-junction as basic pixel sensing element in combination with artificial neural network (ANN), the wavelength readout with a full-scale error of less than 1.5% [...] Read more.

An intelligent sensor for light wavelength readout, suitable for visible range optical applications, has been developed. Using buried triple photo-junction as basic pixel sensing element in combination with artificial neural network (ANN), the wavelength readout with a full-scale error of less than 1.5% over the range of 400 to 780 nm can be achieved. Through this work, the applicability of the ANN approach in optical sensing is investigated and compared with conventional methods, and a good compromise between accuracy and the possibility for on-chip implementation was thus found. Indeed, this technique can serve different purposes and may replace conventional methods. Full article

(This article belongs to the Special Issue Neural Networks and Sensors)

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12 pages, 489 KiB

Open AccessArticle

A MEMS-based Benzene Gas Sensor with a Self-heating WO₃ Sensing Layer

by Ming-Tsun Ke¹, Mu-Tsun Lee¹, Chia-Yen Lee^2,* and Lung-Ming Fu^2,*

¹ Department of Energy and Refrigerating Air-conditioning Engineering, National Taipei University of Technology, Taiwan, Taiwan 106

² Department of Materials Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan 912

Sensors 2009, 9(4), 2895-2906; https://doi.org/10.3390/s90402895 - 21 Apr 2009

Cited by 81 | Viewed by 18573

Abstract

In the study, a MEMS-based benzene gas sensor is presented, consisting of a quartz substrate, a thin-film WO₃ sensing layer, an integrated Pt micro-heater, and Pt interdigitated electrodes (IDEs). When benzene is present in the atmosphere, oxidation occurs on the heated WO [...] Read more.

In the study, a MEMS-based benzene gas sensor is presented, consisting of a quartz substrate, a thin-film WO₃ sensing layer, an integrated Pt micro-heater, and Pt interdigitated electrodes (IDEs). When benzene is present in the atmosphere, oxidation occurs on the heated WO₃ sensing layer. This causes a change in the electrical conductivity of the WO₃ film, and hence changes the resistance between the IDEs. The benzene concentration is then computed from the change in the measured resistance. A specific orientation of the WO₃ layer is obtained by optimizing the sputtering process parameters. It is found that the sensitivity of the gas sensor is optimized at a working temperature of 300 °C. At the optimal working temperature, the experimental results show that the sensor has a high degree of sensitivity (1.0 KΩ ppm^-1), a low detection limit (0.2 ppm) and a rapid response time (35 s). Full article

(This article belongs to the Special Issue Gas Sensors 2009)

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19 pages, 851 KiB

Open AccessArticle

Interpretation of Absorption Bands in Airborne Hyperspectral Radiance Data

by Karl H. Szekielda¹, Jeffrey H. Bowles^2,*, David B. Gillis² and W. David Miller³

¹ NRL/ASEE Summer Senior Faculty Fellow, on leave from the City University of New York, Hunter College, USA

² Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Ave, SW, Washington, DC 20375, USA

³ Computational Physics Inc., Remote Sensing Division, Naval Research Laboratory, 4555 Overlook Ave, SW, Washington, DC 20375, USA

Sensors 2009, 9(4), 2907-2925; https://doi.org/10.3390/s90402907 - 22 Apr 2009

Cited by 9 | Viewed by 15479

Abstract

It is demonstrated that hyperspectral imagery can be used, without atmospheric correction, to determine the presence of accessory phytoplankton pigments in coastal waters using derivative techniques. However, care must be taken not to confuse other absorptions for those caused by the presence of [...] Read more.

It is demonstrated that hyperspectral imagery can be used, without atmospheric correction, to determine the presence of accessory phytoplankton pigments in coastal waters using derivative techniques. However, care must be taken not to confuse other absorptions for those caused by the presence of pigments. Atmospheric correction, usually the first step to making products from hyperspectral data, may not completely remove Fraunhofer lines and atmospheric absorption bands and these absorptions may interfere with identification of phytoplankton accessory pigments. Furthermore, the ability to resolve absorption bands depends on the spectral resolution of the spectrometer, which for a fixed spectral range also determines the number of observed bands. Based on this information, a study was undertaken to determine under what circumstances a hyperspectral sensor may determine the presence of pigments. As part of the study a hyperspectral imager was used to take high spectral resolution data over two different water masses. In order to avoid the problems associated with atmospheric correction this data was analyzed as radiance data without atmospheric correction. Here, the purpose was to identify spectral regions that might be diagnostic for photosynthetic pigments. Two well proven techniques were used to aid in absorption band recognition, the continuum removal of the spectra and the fourth derivative. The findings in this study suggest that interpretation of absorption bands in remote sensing data, whether atmospherically corrected or not, have to be carefully reviewed when they are interpreted in terms of photosynthetic pigments. Full article

(This article belongs to the Section Remote Sensors)

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18 pages, 257 KiB

Open AccessArticle

Language-Based Access to Large Sensor Repositories

by Peter Baumann

Jacobs University Bremen, Campus Ring 12, 28759 Bremen, Germany

Sensors 2009, 9(4), 2926-2943; https://doi.org/10.3390/s90402926 - 22 Apr 2009

Cited by 1 | Viewed by 13339

Abstract

Sensor data have broadened their scope recently, ranging now from the simple time series measurements to, e.g., hyperspectral satellite image maps timeseries. In addition to observed data, simulation data increasingly have to be merged, for example 4-D ocean and atmospheric data. The majority [...] Read more.

Sensor data have broadened their scope recently, ranging now from the simple time series measurements to, e.g., hyperspectral satellite image maps timeseries. In addition to observed data, simulation data increasingly have to be merged, for example 4-D ocean and atmospheric data. The majority of these data fall into the category of multi-dimensional rasters. However, when it comes to flexible retrieval, including sensor data search, aggregation, analysis, fusion, etc., standard query language support in the past has not kept up with the service level of, e.g., metadata retrieval. To close this gap, the Open GeoSpatial Consortium (OGC) has issued the Web Coverage Processing Service (WCPS) Standard in December 2008. WCPS defines a request language for multi-dimensional raster data, suitable for specifying navigation, download, and analysis of sensor, image, and statistics data. This contribution emphasises sensor data modeling and the perspectives for an integrated, cross-dimensional sensor data retrieval. Further, the WCPS reference implementation is briefly discussed. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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Graphical abstract

7 pages, 378 KiB

Open AccessArticle

Compact Integration of a GSM-19 Magnetic Sensor with High-Precision Positioning using VRS GNSS Technology

by Angel Martín^*, Jorge Padín, Ana Belén Anquela, Juán Sánchez and Santiago Belda

Department of Cartographical Engineering, Geodesy and Photogrammetry. Polytechnic University of Valencia. Camino de Vera s/n, 46022, Valencia, Spain

Sensors 2009, 9(4), 2944-2950; https://doi.org/10.3390/s90402944 - 22 Apr 2009

Cited by 9 | Viewed by 15403

Abstract

Magnetic data consists of a sequence of collected points with spatial coordinates and magnetic information. The spatial location of these points needs to be as exact as possible in order to develop a precise interpretation of magnetic anomalies. GPS is a valuable tool [...] Read more.

Magnetic data consists of a sequence of collected points with spatial coordinates and magnetic information. The spatial location of these points needs to be as exact as possible in order to develop a precise interpretation of magnetic anomalies. GPS is a valuable tool for accomplishing this objective, especially if the RTK approach is used. In this paper the VRS (Virtual Reference Station) technique is introduced as a new approach for real-time positioning of magnetic sensors. The main advantages of the VRS approach are, firstly, that only a single GPS receiver is needed (no base station is necessary), reducing field work and equipment costs. Secondly, VRS can operate at distances separated 50-70 km from the reference stations without degrading accuracy. A compact integration of a GSM-19 magnetometer sensor with a geodetic GPS antenna is presented; this integration does not diminish the operational flexibility of the original magnetometer and can work with the VRS approach. The coupled devices were tested in marshlands around Gandia, a city located approximately 100 km South of Valencia (Spain), thought to be the site of a Roman cemetery. The results obtained show adequate geometry and high-precision positioning for the structures to be studied (a comparison with the original low precision GPS of the magnetometer is presented). Finally, the results of the magnetic survey are of great interest for archaeological purposes. Full article

(This article belongs to the Section Remote Sensors)

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17 pages, 970 KiB

Open AccessArticle

New Dielectric Sensors and Sensing Techniques for Soil and Snow Moisture Measurements

by Markus Stacheder^*, Franz Koeniger and Rainer Schuhmann

Karlsruhe Institute of Technology (KIT), Competence Centre for Material Moisture (CMM), c/o Forschungszentrum Karlsruhe, Institut für Funktionelle Grenzflächen, Postfach 3640, 76021 Karlsruhe, Germany

Sensors 2009, 9(4), 2951-2967; https://doi.org/10.3390/s90402951 - 22 Apr 2009

Cited by 58 | Viewed by 15970

Abstract

Measurements of material moisture are essential in fields such as agriculture or civil engineering. Electromagnetic techniques, more precisely dielectric methods, have gained wide acceptance in the last decades. Frequency or Time Domain methods take advantage of the high dielectric permittivity of water compared [...] Read more.

Measurements of material moisture are essential in fields such as agriculture or civil engineering. Electromagnetic techniques, more precisely dielectric methods, have gained wide acceptance in the last decades. Frequency or Time Domain methods take advantage of the high dielectric permittivity of water compared to dry materials. This paper presents four new dielectric sensors for the determination of soil or snow water content. After a short introduction into the principles, both the hardware and operating mode of each sensor are described. Field test results show the advantages and potentials such as automatic measurement and profiling, state-of-ground detection or large-scale determination. From the results it follows that the presented sensors offer promising new tools for modern environmental research. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Germany)

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8 pages, 112 KiB

Open AccessArticle

Use of Vegetation Health Data for Estimation of Aus Rice Yield in Bangladesh

by Atiqur Rahman^1,*, Leonid Roytman¹, Nir Y. Krakauer¹, Mohammad Nizamuddin¹ and Mitch Goldberg²

¹ NOAA-CREST, CCNY,138th Street and Convent Ave, New York, NY 10031,USA

² NESDIS/NOAA, 5200 Auth Rd. Camp Spring, MD 20746, USA

Sensors 2009, 9(4), 2968-2975; https://doi.org/10.3390/s90402968 - 23 Apr 2009

Cited by 45 | Viewed by 14707

Abstract

Rice is a vital staple crop for Bangladesh and surrounding countries, with interannual variation in yields depending on climatic conditions. We compared Bangladesh yield of aus rice, one of the main varieties grown, from official agricultural statistics with Vegetation Health (VH) Indices [Vegetation [...] Read more.

Rice is a vital staple crop for Bangladesh and surrounding countries, with interannual variation in yields depending on climatic conditions. We compared Bangladesh yield of aus rice, one of the main varieties grown, from official agricultural statistics with Vegetation Health (VH) Indices [Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Vegetation Health Index (VHI)] computed from Advanced Very High Resolution Radiometer (AVHRR) data covering a period of 15 years (1991–2005). A strong correlation was found between aus rice yield and VCI and VHI during the critical period of aus rice development that occurs during March-April (weeks 8–13 of the year), several months in advance of the rice harvest. Stepwise principal component regression (PCR) was used to construct a model to predict yield as a function of critical-period VHI. The model reduced the yield prediction error variance by 62% compared with a prediction of average yield for each year. Remote sensing is a valuable tool for estimating rice yields well in advance of harvest and at a low cost. Full article

(This article belongs to the Section Remote Sensors)

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24 pages, 468 KiB

Open AccessReview

Magnetic Particle-Based Hybrid Platforms for Bioanalytical Sensors

by Lia Stanciu^1,*, Yu-Ho Won¹, Mallikarjunarao Ganesana² and Silvana Andreescu^2,*

¹ School of Materials Engineering, Purdue University, West Lafayette, IN 47907-2045, USA

² Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY 13699-5810, USA

Sensors 2009, 9(4), 2976-2999; https://doi.org/10.3390/s90402976 - 23 Apr 2009

Cited by 81 | Viewed by 18155

Abstract

Biomagnetic nano and microparticles platforms have attracted considerable interest in the field of biological sensors due to their interesting physico-chemical properties, high specific surface area, good mechanical stability and opportunities for generating magneto-switchable devices. This review discusses recent advances in the development and [...] Read more.

Biomagnetic nano and microparticles platforms have attracted considerable interest in the field of biological sensors due to their interesting physico-chemical properties, high specific surface area, good mechanical stability and opportunities for generating magneto-switchable devices. This review discusses recent advances in the development and characterization of active biomagnetic nanoassemblies, their interaction with biological molecules and their use in bioanalytical sensors. Full article

(This article belongs to the Special Issue Toxin Sensors)

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11 pages, 211 KiB

Open AccessArticle

Matrix Effects on the Microcystin-LR Fluorescent Immunoassay Based on Optical Biosensor

by Feng Long¹, An-na Zhu², Jian-Wu Sheng¹, Miao He¹ and Han-Chang Shi^1,*

¹ Environmental Simulation and Pollution Control State Key Joint Laboratory, Dept. of Environment Science and Engineering, Tsinghua University, Beijing 100084, P.R. China

² Research Institute of Chemical Defence, Beijing 102204, P.R. China

Sensors 2009, 9(4), 3000-3010; https://doi.org/10.3390/s90403000 - 23 Apr 2009

Cited by 16 | Viewed by 15151

Abstract

Matrix effects on the microcystin-LR fluorescent immunoassay based on the evanescent wave all-fiber immunosensor (EWAI) and their elimination methods were studied. The results indicated that PBS and humic acid did not affect the monitoring of samples under the investigated conditions. When the pH [...] Read more.

Matrix effects on the microcystin-LR fluorescent immunoassay based on the evanescent wave all-fiber immunosensor (EWAI) and their elimination methods were studied. The results indicated that PBS and humic acid did not affect the monitoring of samples under the investigated conditions. When the pH was less than 6 or higher than 8, the fluorescence signals detected by immunosensor systems were obviously reduced with the decrease or increase of pH. When the pH ranged from 6 to 8, IC₅₀ and the linear working range of MC-LR calculated from the detection curves were 1.01~1.04 μg/L and 0.12~10.5 μg/L, respectively, which was favourable for an MC-LR immunoassay. Low concentrations of Cu²⁺ rarely affected the detection performance of MC-LR. When the concentration of CuSO₄ was higher than 5 mg/L, the fluorescence signal detected by EWAI clearly decreased, and when the concentration of CuSO₄ was 10 mg/L, the fluorescence signal detected was reduced by 70%. The influence of Cu²⁺ on the immunoassay could effectively be compromised when chelating reagent EDTA was added to the pre-reaction mixture. Full article

(This article belongs to the Section Biosensors)

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22 pages, 443 KiB

Open AccessArticle

Heat Transfer Measurements with Surface Mounted Foil-Sensors in an Active Mode: A Comprehensive Review and a New Design

by Horst Mocikat and Heinz Herwig^*

Hamburg University of Technology, Institute of Thermo-Fluid Dynamics, Denickestr. 17, D 21073 Hamburg, Germany

Sensors 2009, 9(4), 3011-3032; https://doi.org/10.3390/s90403011 - 23 Apr 2009

Cited by 16 | Viewed by 15229

Abstract

A comprehensive review of film-sensors shows that they are primarily operated in a passive mode, i.e. without being actively heated to an extent, whereby they create a heat transfer situation on their own. Only when these sensors are used for wall shear stress [...] Read more.

A comprehensive review of film-sensors shows that they are primarily operated in a passive mode, i.e. without being actively heated to an extent, whereby they create a heat transfer situation on their own. Only when these sensors are used for wall shear stress measurements, the detection of laminar/turbulent transition, or the measurement of certain flow velocities, they are operated in an active mode, i.e. heated by an electrical current (after an appropriate calibration). In our study we demonstrate how these R(T)-based sensors (temperature dependence of the electrical resistance R) can also be applied in an active mode for heat transfer measurements. These measurements can be made on cold, unheated bodies, provided certain requirements with respect to the flow field are fulfilled. Our new sensors are laminated nickel- and polyimide-foils manufactured with a special technology, which is also described in detail. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Germany)

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23 pages, 968 KiB

Open AccessArticle

Sensing Human Activity: GPS Tracking

by Stefan Van der Spek^1,*

, Jeroen Van Schaick¹, Peter De Bois^{1, 2} and Remco De Haan¹

¹ Department of Urbanism, Faculty of Architecture, Delft University of Technology, Julianalaan 132-134, 2628 BL, DELFT, the Netherlands

² Chair MISSU, Multifunctional (sustainable) Spatial Use, University of Applied Sciences, PO Box 1025, 1000 BA, Amsterdam, the Netherlands

Sensors 2009, 9(4), 3033-3055; https://doi.org/10.3390/s90403033 - 24 Apr 2009

Cited by 105 | Viewed by 27019

Abstract

The enhancement of GPS technology enables the use of GPS devices not only as navigation and orientation tools, but also as instruments used to capture travelled routes: as sensors that measure activity on a city scale or the regional scale. TU Delft developed [...] Read more.

The enhancement of GPS technology enables the use of GPS devices not only as navigation and orientation tools, but also as instruments used to capture travelled routes: as sensors that measure activity on a city scale or the regional scale. TU Delft developed a process and database architecture for collecting data on pedestrian movement in three European city centres, Norwich, Rouen and Koblenz, and in another experiment for collecting activity data of 13 families in Almere (The Netherlands) for one week. The question posed in this paper is: what is the value of GPS as ‘sensor technology’ measuring activities of people? The conclusion is that GPS offers a widely useable instrument to collect invaluable spatial-temporal data on different scales and in different settings adding new layers of knowledge to urban studies, but the use of GPS-technology and deployment of GPS-devices still offers significant challenges for future research. Full article

(This article belongs to the Special Issue Workshop Sensing A Changing World)

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22 pages, 738 KiB

Open AccessArticle

Application of Neurocomputing for Data Approximation and Classification in Wireless Sensor Networks

by Amir Jabbari^*, Reiner Jedermann, Ramanan Muthuraman and Walter Lang

Department of Electrical Engineering, Institute of Micro sensors, Actuators and Systems (IMSAS), University of Bremen, NW1 Building, D-28359 Bremen, Germany

Sensors 2009, 9(4), 3056-3077; https://doi.org/10.3390/s90403056 - 24 Apr 2009

Cited by 14 | Viewed by 12445

Abstract

A new application of neurocomputing for data approximation and classification is introduced to process data in a wireless sensor network. For this purpose, a simplified dynamic sliding backpropagation algorithm is implemented on a wireless sensor network for transportation applications. It is able to [...] Read more.

A new application of neurocomputing for data approximation and classification is introduced to process data in a wireless sensor network. For this purpose, a simplified dynamic sliding backpropagation algorithm is implemented on a wireless sensor network for transportation applications. It is able to approximate temperature and humidity in sensor nodes. In addition, two architectures of “radial basis function” (RBF) classifiers are introduced with probabilistic features for data classification in sensor nodes. The applied approximation and classification algorithms could be used in similar applications for data processing in embedded systems. Full article

(This article belongs to the Special Issue Neural Networks and Sensors)

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12 pages, 477 KiB

Open AccessArticle

Networked Estimation for Event-Based Sampling Systems with Packet Dropouts

by Vinh Hao Nguyen and Young Soo Suh^*

Department of Electrical Engineering, University of Ulsan, Namgu, Ulsan 680-749, Korea

Sensors 2009, 9(4), 3078-3089; https://doi.org/10.3390/s90403078 - 24 Apr 2009

Cited by 26 | Viewed by 13491

Abstract

This paper is concerned with a networked estimation problem in which sensor data are transmitted over the network. In the event-based sampling scheme known as level-crossing or send-on-delta (SOD), sensor data are transmitted to the estimator node if the difference between the current [...] Read more.

This paper is concerned with a networked estimation problem in which sensor data are transmitted over the network. In the event-based sampling scheme known as level-crossing or send-on-delta (SOD), sensor data are transmitted to the estimator node if the difference between the current sensor value and the last transmitted one is greater than a given threshold. Event-based sampling has been shown to be more efficient than the time-triggered one in some situations, especially in network bandwidth improvement. However, it cannot detect packet dropout situations because data transmission and reception do not use a periodical time-stamp mechanism as found in time-triggered sampling systems. Motivated by this issue, we propose a modified event-based sampling scheme called modified SOD in which sensor data are sent when either the change of sensor output exceeds a given threshold or the time elapses more than a given interval. Through simulation results, we show that the proposed modified SOD sampling significantly improves estimation performance when packet dropouts happen. Full article

(This article belongs to the Section Chemical Sensors)

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19 pages, 827 KiB

Open AccessArticle

Simulation of EO-1 Hyperion Data from ALI Multispectral Data Based on the Spectral Reconstruction Approach

by Bo Liu¹, Lifu Zhang^1,*, Xia Zhang¹, Bing Zhang² and Qingxi Tong¹

¹ State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, 100101, P.R. China

² Center for Earth Observation and Digital Earth, Chinese Academy of Sciences, Beijing, 100080, P.R. China

Sensors 2009, 9(4), 3090-3108; https://doi.org/10.3390/s90403090 - 24 Apr 2009

Cited by 45 | Viewed by 16796

Abstract

Data simulation is widely used in remote sensing to produce imagery for a new sensor in the design stage, for scale issues of some special applications, or for testing of novel algorithms. Hyperspectral data could provide more abundant information than traditional multispectral data [...] Read more.

Data simulation is widely used in remote sensing to produce imagery for a new sensor in the design stage, for scale issues of some special applications, or for testing of novel algorithms. Hyperspectral data could provide more abundant information than traditional multispectral data and thus greatly extend the range of remote sensing applications. Unfortunately, hyperspectral data are much more difficult and expensive to acquire and were not available prior to the development of operational hyperspectral instruments, while large amounts of accumulated multispectral data have been collected around the world over the past several decades. Therefore, it is reasonable to examine means of using these multispectral data to simulate or construct hyperspectral data, especially in situations where hyperspectral data are necessary but hard to acquire. Here, a method based on spectral reconstruction is proposed to simulate hyperspectral data (Hyperion data) from multispectral Advanced Land Imager data (ALI data). This method involves extraction of the inherent information of source data and reassignment to newly simulated data. A total of 106 bands of Hyperion data were simulated from ALI data covering the same area. To evaluate this method, we compare the simulated and original Hyperion data by visual interpretation, statistical comparison, and classification. The results generally showed good performance of this method and indicated that most bands were well simulated, and the information both preserved and presented well. This makes it possible to simulate hyperspectral data from multispectral data for testing the performance of algorithms, extend the use of multispectral data and help the design of a virtual sensor. Full article

(This article belongs to the Special Issue Sensor Algorithms)

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13 pages, 1209 KiB

Open AccessArticle

A Near-Infrared Spectrometer Based on Novel Grating Light Modulators

by Wei Wei^{1, 2,*}, Shanglian Huang^{1, 2}, Ning Wang^{1, 2}, Zhu Jin^{1, 2, 3}, Jie Zhang^{1, 2} and Weimin Chen^{1, 2}

¹ Key Lab of Opto-electronic Technology and Systems, Education Ministry of China, Chongqing, 400044, P.R. China

² Optoelectronic Engineering Department, Chongqing University, Chongqing, 400044, P.R. China

³ Microsystem Center, Chongqing University, Chongqing, 400044, P.R. China

Sensors 2009, 9(4), 3109-3121; https://doi.org/10.3390/s90403109 - 24 Apr 2009

Cited by 12 | Viewed by 14730

Abstract

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of [...] Read more.

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification. Full article

(This article belongs to the Special Issue Selected Papers from the 1st International Conference of the Chinese Society of Micro/Nano Technology)

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27 pages, 3014 KiB

Open AccessReview

Overview of Electrochemical DNA Biosensors: New Approaches to Detect the Expression of Life

by Stefano Cagnin¹, Marcelo Caraballo², Carlotta Guiducci^3,4

, Paolo Martini¹, Marty Ross², Mark SantaAna², David Danley², Todd West² and Gerolamo Lanfranchi^1,*,*

¹ CRIBI Biotechnology Centre and Department of Biology, University of Padova, via U. Bassi 58/B 35121 Padova, Italy

² CombiMatrix Corporation, 6500 Harbour Heights Pkwy, 301, Mukilteo, WA 98275, USA

³ DEIS Dipartimento di Elettronica, Informatica e Sistemistica, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy

⁴ IBI-EPFL, Institute of Bioengineering, Ecole Polytechnique Federale de Lausanne, Station 15 CH-1015 Lausanne, Switzerland

Sensors 2009, 9(4), 3122-3148; https://doi.org/10.3390/s90403122 - 24 Apr 2009

Cited by 115 | Viewed by 29643

Abstract

DNA microarrays are an important tool with a variety of applications in gene expression studies, genotyping, pharmacogenomics, pathogen classification, drug discovery, sequencing and molecular diagnostics. They are having a strong impact in medical diagnostics for cancer, toxicology and infectious disease applications. A series [...] Read more.

DNA microarrays are an important tool with a variety of applications in gene expression studies, genotyping, pharmacogenomics, pathogen classification, drug discovery, sequencing and molecular diagnostics. They are having a strong impact in medical diagnostics for cancer, toxicology and infectious disease applications. A series of papers have been published describing DNA biochips as alternative to conventional microarray platforms to facilitate and ameliorate the signal readout. In this review, we will consider the different methods proposed for biochip construction, focusing on electrochemical detection of DNA. We also introduce a novel single-stranded DNA platform performing high-throughput SNP detection and gene expression profiling. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy)

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Sensors, Volume 9, Issue 4 (April 2009) – 58 articles , Pages 2222-3160

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