Next Issue
Volume 11, September
Previous Issue
Volume 11, July
 
 
sensors-logo

Journal Browser

Journal Browser

Sensors, Volume 11, Issue 8 (August 2011) – 53 articles , Pages 7302-8202

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
2809 KiB  
Article
LinkMind: Link Optimization in Swarming Mobile Sensor Networks
by Trung Dung Ngo
Sensors 2011, 11(8), 8180-8202; https://doi.org/10.3390/s110808180 - 23 Aug 2011
Cited by 10 | Viewed by 7835 | Correction
Abstract
A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One [...] Read more.
A swarming mobile sensor network is comprised of a swarm of wirelessly connected mobile robots equipped with various sensors. Such a network can be applied in an uncertain environment for services such as cooperative navigation and exploration, object identification and information gathering. One of the most advantageous properties of the swarming wireless sensor network is that mobile nodes can work cooperatively to organize an ad-hoc network and optimize the network link capacity to maximize the transmission of gathered data from a source to a target. This paper describes a new method of link optimization of swarming mobile sensor networks. The new method is based on combination of the artificial potential force guaranteeing connectivities of the mobile sensor nodes and the max-flow min-cut theorem of graph theory ensuring optimization of the network link capacity. The developed algorithm is demonstrated and evaluated in simulation. Full article
(This article belongs to the Special Issue Bioinspired Sensor Systems)
Show Figures

519 KiB  
Article
FPGA-Based Multimodal Embedded Sensor System Integrating Low- and Mid-Level Vision
by Guillermo Botella, José Antonio Martín H., Matilde Santos and Uwe Meyer-Baese
Sensors 2011, 11(8), 8164-8179; https://doi.org/10.3390/s110808164 - 22 Aug 2011
Cited by 28 | Viewed by 14066
Abstract
Motion estimation is a low-level vision task that is especially relevant due to its wide range of applications in the real world. Many of the best motion estimation algorithms include some of the features that are found in mammalians, which would demand huge [...] Read more.
Motion estimation is a low-level vision task that is especially relevant due to its wide range of applications in the real world. Many of the best motion estimation algorithms include some of the features that are found in mammalians, which would demand huge computational resources and therefore are not usually available in real-time. In this paper we present a novel bioinspired sensor based on the synergy between optical flow and orthogonal variant moments. The bioinspired sensor has been designed for Very Large Scale Integration (VLSI) using properties of the mammalian cortical motion pathway. This sensor combines low-level primitives (optical flow and image moments) in order to produce a mid-level vision abstraction layer. The results are described trough experiments showing the validity of the proposed system and an analysis of the computational resources and performance of the applied algorithms. Full article
(This article belongs to the Special Issue Bioinspired Sensor Systems)
Show Figures

931 KiB  
Article
An Amperometric Biosensor for Glucose Determination Prepared from Glucose Oxidase Immobilized in Polyaniline-Polyvinylsulfonate Film
by Fatma Arslan, Selvin Ustabaş and Halit Arslan
Sensors 2011, 11(8), 8152-8163; https://doi.org/10.3390/s110808152 - 22 Aug 2011
Cited by 56 | Viewed by 9158
Abstract
In this study, a novel amperometric glucose biosensor with immobilization of glucose oxidase on electrochemically polymerized polyaniline-polyvinylsulphonate (Pani-Pvs) films has been accomplished via the entrapment technique. Electropolymerization of aniline on the Pt surface of the Pt electrode was carried out at constant potential [...] Read more.
In this study, a novel amperometric glucose biosensor with immobilization of glucose oxidase on electrochemically polymerized polyaniline-polyvinylsulphonate (Pani-Pvs) films has been accomplished via the entrapment technique. Electropolymerization of aniline on the Pt surface of the Pt electrode was carried out at constant potential (0.75 V, vs. Ag/AgCl) using an electrochemical cell containing aniline and polyvinylsulphonate. Firstly, the optimum working conditions for preparing polyaniline-polyvinylsulfonate films were investigated. Determination of glucose was carried out by the oxidation of enzymatically produced H2O2 at 0.4 V vs. Ag/AgCl. The effects of pH and temperature were investigated and the optimum pH value was found to be 7.5. The storage stability and operational stability of the enzyme electrode were also studied. The results show that 75% of the response current was retained after 16 activity assays. The prepared glucose biosensor retained 80.6% of initial activity after 40 days when stored in 0.1 M phosphate buffer solution at 4 °C. Full article
(This article belongs to the Section Biosensors)
Show Figures

1116 KiB  
Article
Fabrication and Characterization of Polyaniline/PVA Humidity Microsensors
by Ming-Zhi Yang, Ching-Liang Dai and Wei-Yi Lin
Sensors 2011, 11(8), 8143-8151; https://doi.org/10.3390/s110808143 - 19 Aug 2011
Cited by 38 | Viewed by 9636
Abstract
This study presents the fabrication and characterization of a humidity microsensor that consists of interdigitated electrodes and a sensitive film. The area of the humidity microsensor is about 2 mm2. The sensitive film is polyaniline doping polyvinyl alcohol (PVA) that is [...] Read more.
This study presents the fabrication and characterization of a humidity microsensor that consists of interdigitated electrodes and a sensitive film. The area of the humidity microsensor is about 2 mm2. The sensitive film is polyaniline doping polyvinyl alcohol (PVA) that is prepared by the sol-gel method, and the film has nanofiber and porous structures that help increase the sensing reaction. The commercial 0.35 mm Complimentary Metal Oxide Semiconductor (CMOS) process is used to fabricate the humidity microsensor. The sensor needs a post-CMOS process to etch the sacrificial layer and to coat the sensitive film on the interdigitated electrodes. The sensor produces a change in resistance as the polyaniline/PVA film absorbs or desorbs vapor. Experimental results show that the sensitivity of the humidity sensor is about 12.6 kΩ/%RH at 25 °C. Full article
(This article belongs to the Special Issue Modeling, Testing and Reliability Issues in MEMS Engineering 2011)
Show Figures

938 KiB  
Article
Dual-Functional On-Chip AlGaAs/GaAs Schottky Diode for RF Power Detection and Low-Power Rectenna Applications
by Abdul Manaf Hashim, Farahiyah Mustafa, Shaharin Fadzli Abd Rahman and Abdul Rahim Abdul Rahman
Sensors 2011, 11(8), 8127-8142; https://doi.org/10.3390/s110808127 - 18 Aug 2011
Cited by 16 | Viewed by 11018
Abstract
A Schottky diode has been designed and fabricated on an n-AlGaAs/GaAs high-electron-mobility-transistor (HEMT) structure. Current-voltage (I-V) measurements show good device rectification, with a Schottky barrier height of 0.4349 eV for Ni/Au metallization. The differences between the Schottky barrier height and [...] Read more.
A Schottky diode has been designed and fabricated on an n-AlGaAs/GaAs high-electron-mobility-transistor (HEMT) structure. Current-voltage (I-V) measurements show good device rectification, with a Schottky barrier height of 0.4349 eV for Ni/Au metallization. The differences between the Schottky barrier height and the theoretical value (1.443 eV) are due to the fabrication process and smaller contact area. The RF signals up to 1 GHz are rectified well by the fabricated Schottky diode and a stable DC output voltage is obtained. The increment ratio of output voltage vs input power is 0.2 V/dBm for all tested frequencies, which is considered good enough for RF power detection. Power conversion efficiency up to 50% is obtained at frequency of 1 GHz and input power of 20 dBm with series connection between diode and load, which also shows the device’s good potential as a rectenna device with further improvement. The fabricated n-AlGaAs/GaAs Schottky diode thus provides a conduit for breakthrough designs for RF power detectors, as well as ultra-low power on-chip rectenna device technology to be integrated in nanosystems. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

1989 KiB  
Article
Robustifying Vector Median Filter
by Samuel Morillas and Valentín Gregori
Sensors 2011, 11(8), 8115-8126; https://doi.org/10.3390/s110808115 - 18 Aug 2011
Cited by 28 | Viewed by 7244
Abstract
This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use [...] Read more.
This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use of complimentary information from componentwise analysis allows to build robust outputs from more reliable components. The correlation among the colour channels is taken into account in the processing and, as a result, a more robust filter able to process colour images without introducing colour artifacts is obtained. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter. Objective measures demonstrate the goodness of the achieved improvement. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

2075 KiB  
Article
Common Criteria Related Security Design Patterns for Intelligent Sensors—Knowledge Engineering-Based Implementation
by Andrzej Bialas
Sensors 2011, 11(8), 8085-8114; https://doi.org/10.3390/s110808085 - 17 Aug 2011
Cited by 15 | Viewed by 7782
Abstract
Intelligent sensors experience security problems very similar to those inherent to other kinds of IT products or systems. The assurance for these products or systems creation methodologies, like Common Criteria (ISO/IEC 15408) can be used to improve the robustness of the sensor systems [...] Read more.
Intelligent sensors experience security problems very similar to those inherent to other kinds of IT products or systems. The assurance for these products or systems creation methodologies, like Common Criteria (ISO/IEC 15408) can be used to improve the robustness of the sensor systems in high risk environments. The paper presents the background and results of the previous research on patterns-based security specifications and introduces a new ontological approach. The elaborated ontology and knowledge base were validated on the IT security development process dealing with the sensor example. The contribution of the paper concerns the application of the knowledge engineering methodology to the previously developed Common Criteria compliant and pattern-based method for intelligent sensor security development. The issue presented in the paper has a broader significance in terms that it can solve information security problems in many application domains. Full article
(This article belongs to the Special Issue Collaborative Sensors)
Show Figures

727 KiB  
Article
Sensitivities of Key Parameters in the Preparation of Silver/Silver Chloride Electrodes Used in Harned Cell Measurements of pH
by Paul J. Brewer, Daniela Stoica and Richard J. C. Brown
Sensors 2011, 11(8), 8072-8084; https://doi.org/10.3390/s110808072 - 17 Aug 2011
Cited by 16 | Viewed by 8054
Abstract
A questionnaire was completed by fourteen world leading national metrology institutes to study the influence of several variables in the preparation of Ag/AgCl electrodes on the accuracy of Harned cell measurements of pH. The performance of each institute in the last decade has [...] Read more.
A questionnaire was completed by fourteen world leading national metrology institutes to study the influence of several variables in the preparation of Ag/AgCl electrodes on the accuracy of Harned cell measurements of pH. The performance of each institute in the last decade has been assessed based on their results in eight key comparisons, organized by the Bureau International des Poids et Measures Consultative Committee for Amount of Substance, involving the measurement of pH of phosphate, phthalate, carbonate, borate and tetroxalate buffer solutions. The performance of each laboratory has been correlated to the results of the questionnaire to determine the critical parameters in the preparation of Ag/AgCl electrodes and their sensitivities with respect to the accuracy of pH measurement. This study reveals that the parameters most closely correlated to performance in comparisons are area of electrode wire exposed to the electrolyte, diameter and porosity of the Ag sphere prior to anodisation, amount of Ag converted to AgCl during anodisation, stability times employed for electrodes to reach equilibrium in solution prior to measurement, electrode rejection criteria employed and purity of reagents. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

Graphical abstract

1550 KiB  
Article
A Microring Resonator Based Negative Permeability Metamaterial Sensor
by Jun Sun, Ming Huang, Jing-Jing Yang, Ting-Hua Li and Yao-Zhong Lan
Sensors 2011, 11(8), 8060-8071; https://doi.org/10.3390/s110808060 - 17 Aug 2011
Cited by 8 | Viewed by 8074
Abstract
Metamaterials are artificial multifunctional materials that acquire their material properties from their structure, rather than inheriting them directly from the materials they are composed of, and they may provide novel tools to significantly enhance the sensitivity and resolution of sensors. In this paper, [...] Read more.
Metamaterials are artificial multifunctional materials that acquire their material properties from their structure, rather than inheriting them directly from the materials they are composed of, and they may provide novel tools to significantly enhance the sensitivity and resolution of sensors. In this paper, we derive the dispersion relation of a cylindrical dielectric waveguide loaded on a negative permeability metamaterial (NPM) layer, and compute the resonant frequencies and electric field distribution of the corresponding Whispering-Gallery-Modes (WGMs). The theoretical resonant frequency and electric field distribution results are in good agreement with the full wave simulation results. We show that the NPM sensor based on a microring resonator possesses higher sensitivity than the traditional microring sensor since with the evanescent wave amplification and the increase of NPM layer thickness, the sensitivity will be greatly increased. This may open a door for designing sensors with specified sensitivity. Full article
(This article belongs to the Special Issue Optical Resonant Microsensors)
Show Figures

967 KiB  
Article
Height Compensation Using Ground Inclination Estimation in Inertial Sensor-Based Pedestrian Navigation
by Sang Kyeong Park and Young Soo Suh
Sensors 2011, 11(8), 8045-8059; https://doi.org/10.3390/s110808045 - 15 Aug 2011
Cited by 9 | Viewed by 7087
Abstract
In an inertial sensor-based pedestrian navigation system, the position is estimated by double integrating external acceleration. A new algorithm is proposed to reduce z axis position (height) error. When a foot is on the ground, a foot angle is estimated using accelerometer output. [...] Read more.
In an inertial sensor-based pedestrian navigation system, the position is estimated by double integrating external acceleration. A new algorithm is proposed to reduce z axis position (height) error. When a foot is on the ground, a foot angle is estimated using accelerometer output. Using a foot angle, the inclination angle of a road is estimated. Using this road inclination angle, height difference of one walking step is estimated and this estimation is used to reduce height error. Through walking experiments on roads with different inclination angles, the usefulness of the proposed algorithm is verified. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

Graphical abstract

906 KiB  
Article
A Noise-Aware Coding Scheme for Texture Classification
by Mohammad Shoyaib, M. Abdullah-Al-Wadud and Oksam Chae
Sensors 2011, 11(8), 8028-8044; https://doi.org/10.3390/s110808028 - 15 Aug 2011
Cited by 6 | Viewed by 8136
Abstract
Texture-based analysis of images is a very common and much discussed issue in the fields of computer vision and image processing. Several methods have already been proposed to codify texture micro-patterns (texlets) in images. Most of these methods perform well when a given [...] Read more.
Texture-based analysis of images is a very common and much discussed issue in the fields of computer vision and image processing. Several methods have already been proposed to codify texture micro-patterns (texlets) in images. Most of these methods perform well when a given image is noise-free, but real world images contain different types of signal-independent as well as signal-dependent noises originated from different sources, even from the camera sensor itself. Hence, it is necessary to differentiate false textures appearing due to the noises, and thus, to achieve a reliable representation of texlets. In this proposal, we define an adaptive noise band (ANB) to approximate the amount of noise contamination around a pixel up to a certain extent. Based on this ANB, we generate reliable codes named noise tolerant ternary pattern (NTTP) to represent the texlets in an image. Extensive experiments on several datasets from renowned texture databases, such as the Outex and the Brodatz database, show that NTTP performs much better than the state-of-the-art methods. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

1195 KiB  
Article
Detection of Single-Nucleotide Polymorphism on uidA Gene of Escherichia coli by a Multiplexed Electrochemical DNA Biosensor with Oligonucleotide-Incorporated Nonfouling Surface
by Gang Liu, Ruojun Lao, Li Xu, Qin Xu, Lanying Li, Min Zhang, Hao Shen, Sanjay Mathur, Chunhai Fan and Shiping Song
Sensors 2011, 11(8), 8018-8027; https://doi.org/10.3390/s110808018 - 15 Aug 2011
Cited by 16 | Viewed by 11595
Abstract
We report here a practical application of a multiplexed electrochemical DNA sensor for highly specific single-nucleotide polymorphism (SNP) detection. In this work, a 16-electrode array was applied with an oligonucleotide-incorporated nonfouling surfaces (ONS) on each electrode for the resistance of unspecific absorption. The [...] Read more.
We report here a practical application of a multiplexed electrochemical DNA sensor for highly specific single-nucleotide polymorphism (SNP) detection. In this work, a 16-electrode array was applied with an oligonucleotide-incorporated nonfouling surfaces (ONS) on each electrode for the resistance of unspecific absorption. The fully matched target DNA templated the ligation between the capture probe assembled on gold electrodes and the tandem signal probe with a biotin moiety, which could be transduced to peroxidase-based catalyzed amperometric signals. A mutant site (T93G) in uidA gene of E. coli was analyzed in PCR amplicons. 10% percentage of single mismatched mutant gene was detected, which clearly proved the selectivity of the multiplexed electrochemical DNA biosensor when practically applied. Full article
(This article belongs to the Special Issue Biochips)
Show Figures

Graphical abstract

738 KiB  
Article
Field Programmable Gate Array Based Parallel Strapdown Algorithm Design for Strapdown Inertial Navigation Systems
by Zong-Tao Li, Tie-Jun Wu, Can-Long Lin and Long-Hua Ma
Sensors 2011, 11(8), 7993-8017; https://doi.org/10.3390/s110807993 - 15 Aug 2011
Cited by 5 | Viewed by 7911
Abstract
A new generalized optimum strapdown algorithm with coning and sculling compensation is presented, in which the position, velocity and attitude updating operations are carried out based on the single-speed structure in which all computations are executed at a single updating rate that is [...] Read more.
A new generalized optimum strapdown algorithm with coning and sculling compensation is presented, in which the position, velocity and attitude updating operations are carried out based on the single-speed structure in which all computations are executed at a single updating rate that is sufficiently high to accurately account for high frequency angular rate and acceleration rectification effects. Different from existing algorithms, the updating rates of the coning and sculling compensations are unrelated with the number of the gyro incremental angle samples and the number of the accelerometer incremental velocity samples. When the output sampling rate of inertial sensors remains constant, this algorithm allows increasing the updating rate of the coning and sculling compensation, yet with more numbers of gyro incremental angle and accelerometer incremental velocity in order to improve the accuracy of system. Then, in order to implement the new strapdown algorithm in a single FPGA chip, the parallelization of the algorithm is designed and its computational complexity is analyzed. The performance of the proposed parallel strapdown algorithm is tested on the Xilinx ISE 12.3 software platform and the FPGA device XC6VLX550T hardware platform on the basis of some fighter data. It is shown that this parallel strapdown algorithm on the FPGA platform can greatly decrease the execution time of algorithm to meet the real-time and high precision requirements of system on the high dynamic environment, relative to the existing implemented on the DSP platform. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

113 KiB  
Retraction
Retraction: Eldefrawy, M.H.; Khan, M.K.; Alghathbar, K.; Tolba, A.S.; Kim, K.J. Authenticated Key Agreement with Rekeying for Secured Body Sensor Networks. Sensors 2011, 11, 5835-5849.
by Shu-Kun Lin
Sensors 2011, 11(8), 7992; https://doi.org/10.3390/s110807992 - 15 Aug 2011
Cited by 23 | Viewed by 6038
Abstract
It has been brought to our attention by a reader of Sensors that substantial portions of this article [1] have been copied from an earlier publication [2] without credit. After confirming this case with the authors, we have determined that indeed this manuscript [...] Read more.
It has been brought to our attention by a reader of Sensors that substantial portions of this article [1] have been copied from an earlier publication [2] without credit. After confirming this case with the authors, we have determined that indeed this manuscript clearly violates our policy on originality of all material submitted for publication and the generally accepted ethics of scientific publication. Consequently, the Editorial Team and Publisher have determined that it should be retracted. We apologize for any inconvenience this may cause. Full article
2487 KiB  
Article
Broadband Wide Angle Lens Implemented with Dielectric Metamaterials
by John Hunt, Nathan Kundtz, Nathan Landy, Vinh Nguyen, Tim Perram, Anthony Starr and David R. Smith
Sensors 2011, 11(8), 7982-7991; https://doi.org/10.3390/s110807982 - 12 Aug 2011
Cited by 28 | Viewed by 9366
Abstract
The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar detector and emitter arrays. [...] Read more.
The Luneburg lens is a powerful imaging device, exhibiting aberration free focusing for parallel rays incident from any direction. However, its advantages are offset by a focal surface that is spherical and thus difficult to integrate with standard planar detector and emitter arrays. Using the recently developed technique of transformation optics, it is possible to transform the curved focal surface to a flat plane while maintaining the perfect focusing behavior of the Luneburg over a wide field of view. Here we apply these techniques to a lesser-known refractive Luneburg lens and implement the design with a metamaterial composed of a semi-crystalline distribution of holes drilled in a dielectric. In addition, we investigate the aberrations introduced by various approximations made in the implementation of the lens. The resulting design approach has improved mechanical strength with small aberrations and is ideally suited to implementation at infrared and visible wavelengths. Full article
(This article belongs to the Special Issue Metamaterials for Sensing)
Show Figures

1319 KiB  
Review
Ground-Based Optical Measurements at European Flux Sites: A Review of Methods, Instruments and Current Controversies
by Manuela Balzarolo, Karen Anderson, Caroline Nichol, Micol Rossini, Loris Vescovo, Nicola Arriga, Georg Wohlfahrt, Jean-Christophe Calvet, Arnaud Carrara, Sofia Cerasoli, Sergio Cogliati, Fabrice Daumard, Lars Eklundh, Jan A. Elbers, Fatih Evrendilek, Rebecca N. Handcock, Jörg Kaduk, Katja Klumpp, Bernard Longdoz, Giorgio Matteucci, Michele Meroni, Lenoardo Montagnani, Jean-Marc Ourcival, Enrique P. Sánchez-Cañete, Jean-Yves Pontailler, Radoslaw Juszczak, Bob Scholes and M. Pilar Martínadd Show full author list remove Hide full author list
Sensors 2011, 11(8), 7954-7981; https://doi.org/10.3390/s110807954 - 12 Aug 2011
Cited by 79 | Viewed by 18072
Abstract
This paper reviews the currently available optical sensors, their limitations and opportunities for deployment at Eddy Covariance (EC) sites in Europe. This review is based on the results obtained from an online survey designed and disseminated by the Co-cooperation in Science and Technology [...] Read more.
This paper reviews the currently available optical sensors, their limitations and opportunities for deployment at Eddy Covariance (EC) sites in Europe. This review is based on the results obtained from an online survey designed and disseminated by the Co-cooperation in Science and Technology (COST) Action ESO903—“Spectral Sampling Tools for Vegetation Biophysical Parameters and Flux Measurements in Europe” that provided a complete view on spectral sampling activities carried out within the different research teams in European countries. The results have highlighted that a wide variety of optical sensors are in use at flux sites across Europe, and responses further demonstrated that users were not always fully aware of the key issues underpinning repeatability and the reproducibility of their spectral measurements. The key findings of this survey point towards the need for greater awareness of the need for standardisation and development of a common protocol of optical sampling at the European EC sites. Full article
(This article belongs to the Special Issue Sensors in Agriculture and Forestry)
Show Figures

9400 KiB  
Article
The Role of Exploratory Conditions in Bio-Inspired Tactile Sensing of Single Topogical Features
by Raphaël Candelier, Alexis Prevost and Georges Debrégeas
Sensors 2011, 11(8), 7934-7953; https://doi.org/10.3390/s110807934 - 11 Aug 2011
Cited by 12 | Viewed by 8513
Abstract
We investigate the mechanism of tactile transduction during active exploration of finely textured surfaces using a tactile sensor mimicking the human fingertip. We focus in particular on the role of exploratory conditions in shaping the subcutaneous mechanical signals. The sensor has been designed [...] Read more.
We investigate the mechanism of tactile transduction during active exploration of finely textured surfaces using a tactile sensor mimicking the human fingertip. We focus in particular on the role of exploratory conditions in shaping the subcutaneous mechanical signals. The sensor has been designed by integrating a linear array of MEMS micro-force sensors in an elastomer layer. We measure the response of the sensors to the passage of elementary topographical features at constant velocity and normal load, such as a small hole on a flat substrate. Each sensor’s response is found to strongly depend on its relative location with respect to the substrate/skin contact zone, a result which can be quantitatively understood within the scope of a linear model of tactile transduction. The modification of the response induced by varying other parameters, such as the thickness of the elastic layer and the confining load, are also correctly captured by this model. We further demonstrate that the knowledge of these characteristic responses allows one to dynamically evaluate the position of a small hole within the contact zone, based on the micro-force sensors signals, with a spatial resolution an order of magnitude better than the intrinsic resolution of individual sensors. Consequences of these observations on robotic tactile sensing are briefly discussed. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

1053 KiB  
Article
Network Coding on Heterogeneous Multi-Core Processors for Wireless Sensor Networks
by Deokho Kim, Karam Park and Won W. Ro
Sensors 2011, 11(8), 7908-7933; https://doi.org/10.3390/s110807908 - 11 Aug 2011
Cited by 8 | Viewed by 8271
Abstract
While network coding is well known for its efficiency and usefulness in wireless sensor networks, the excessive costs associated with decoding computation and complexity still hinder its adoption into practical use. On the other hand, high-performance microprocessors with heterogeneous multi-cores would be used [...] Read more.
While network coding is well known for its efficiency and usefulness in wireless sensor networks, the excessive costs associated with decoding computation and complexity still hinder its adoption into practical use. On the other hand, high-performance microprocessors with heterogeneous multi-cores would be used as processing nodes of the wireless sensor networks in the near future. To this end, this paper introduces an efficient network coding algorithm developed for the heterogenous multi-core processors. The proposed idea is fully tested on one of the currently available heterogeneous multi-core processors referred to as the Cell Broadband Engine. Full article
(This article belongs to the Special Issue Microprocessors and System-on-Chip)
Show Figures

2032 KiB  
Article
A Low-Cost CMOS-MEMS Piezoresistive Accelerometer with Large Proof Mass
by Mohd Haris Md Khir, Peng Qu and Hongwei Qu
Sensors 2011, 11(8), 7892-7907; https://doi.org/10.3390/s110807892 - 11 Aug 2011
Cited by 41 | Viewed by 12097
Abstract
This paper reports a low-cost, high-sensitivity CMOS-MEMS piezoresistive accelerometer with large proof mass. In the device fabricated using ON Semiconductor 0.5 μm CMOS technology, an inherent CMOS polysilicon thin film is utilized as the piezoresistive sensing material. A full Wheatstone bridge was constructed [...] Read more.
This paper reports a low-cost, high-sensitivity CMOS-MEMS piezoresistive accelerometer with large proof mass. In the device fabricated using ON Semiconductor 0.5 μm CMOS technology, an inherent CMOS polysilicon thin film is utilized as the piezoresistive sensing material. A full Wheatstone bridge was constructed through easy wiring allowed by the three metal layers in the 0.5 μm CMOS technology. The device fabrication process consisted of a standard CMOS process for sensor configuration, and a deep reactive ion etching (DRIE) based post-CMOS microfabrication for MEMS structure release. A bulk single-crystal silicon (SCS) substrate is included in the proof mass to increase sensor sensitivity. In device design and analysis, the self heating of the polysilicon piezoresistors and its effect to the sensor performance is also discussed. With a low operating power of 1.5 mW, the accelerometer demonstrates a sensitivity of 0.077 mV/g prior to any amplification. Dynamic tests have been conducted with a high-end commercial calibrating accelerometer as reference. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

720 KiB  
Article
Optimizing Two-Color Semiconductor Nanocrystal Immunoassays in Single Well Microtiter Plate Formats
by Kim E. Sapsford, Samantha Spindel, Travis Jennings, Guoliang Tao, Robert C. Triulzi, W. Russ Algar and Igor L. Medintz
Sensors 2011, 11(8), 7879-7891; https://doi.org/10.3390/s110807879 - 11 Aug 2011
Cited by 21 | Viewed by 9437
Abstract
The simultaneous detection of two analytes, chicken IgY (IgG) and Staphylococcal enterotoxin B (SEB), in the single well of a 96-well plate is demonstrated using luminescent semiconductor quantum dot nanocrystal (NC) tracers. The NC-labeled antibodies were prepared via sulfhydryl-reactive chemistry using a facile [...] Read more.
The simultaneous detection of two analytes, chicken IgY (IgG) and Staphylococcal enterotoxin B (SEB), in the single well of a 96-well plate is demonstrated using luminescent semiconductor quantum dot nanocrystal (NC) tracers. The NC-labeled antibodies were prepared via sulfhydryl-reactive chemistry using a facile protocol that took Full article
(This article belongs to the Special Issue Sensing with Quantum Dots)
Show Figures

Graphical abstract

166 KiB  
Article
LuxCDABE—Transformed Constitutively Bioluminescent Escherichia coli for Toxicity Screening: Comparison with Naturally Luminous Vibrio fischeri
by Imbi Kurvet, Angela Ivask, Olesja Bondarenko, Mariliis Sihtmäe and Anne Kahru
Sensors 2011, 11(8), 7865-7878; https://doi.org/10.3390/s110807865 - 11 Aug 2011
Cited by 51 | Viewed by 12559
Abstract
We show that in vitro toxicity assay based on inhibition of the bioluminescence of recombinant Escherichia coli encoding thermostable luciferase from Photorhabdus luminescens is a versatile alternative to Vibrio fischeri MicrotoxTM test. Performance of two luxCDABE-transformed E. coli MC1061 constructs (pDNlux) [...] Read more.
We show that in vitro toxicity assay based on inhibition of the bioluminescence of recombinant Escherichia coli encoding thermostable luciferase from Photorhabdus luminescens is a versatile alternative to Vibrio fischeri MicrotoxTM test. Performance of two luxCDABE-transformed E. coli MC1061 constructs (pDNlux) and (pSLlux) otherwise identical, but having 100-fold different background luminescence was compared with the performance of V. fischeri. The microplate luminometer and a kinetic Flash-Assay test format was used that differently from Microtox test is also applicable for high throughput analysis. Toxic effects (30-s till 30-min EC50) of four heavy metals (Zn, Cd, Hg, Cu) and three organic chemicals (aniline, 3,5-dichloroaniline and 3,5-dichlorophenol) were studied. Both E. coli strains had comparable sensitivity and the respective 30-min EC50 values highly correlated (log-log R2 = 0.99; p < 0.01) showing that the sensitivity of the recombinant bacteria towards chemicals analyzed did not depend on the bioluminescence level of the recombinant cells. The most toxic chemical for all used bacterial strains (E. coli, V. fischeri) was mercury whereas the lowest EC50 values for Hg (0.04–0.05 mg/L) and highest EC50 values for aniline (1,300–1,700 mg/L) were observed for E. coli strains. Despite of that, toxicity results obtained with both E. coli strains (pSLlux and pDNlux) significantly correlated with V. fischeri results (log-log R2 = 0.70/0.75; p < 0.05/0.01). The use of amino acids (0.25%) and glucose (0.05%)-supplemented M9 medium instead of leucine-supplemented saline significantly (p < 0.05) reduced the apparent toxicity of heavy metals to both E. coli strains up to three orders of magnitude, but had little or no complexing effect on organic compounds. Thus, P. luminescens luxCDABE-transformed E. coli strains can be successfully used for the acute toxicity screening of various types of organic chemicals and heavy metals and can replace V. fischeri in certain cases where the thermostability of luciferase >30 °C is crucial. The kinetic Flash Assay test format of the bioluminescence inhibition assay facilitates high throughput analysis. The assay medium, especially in case of testing heavy metals should be a compromise: optimal for the viability/luminescence of the recombinant test strain and of minimum complexing potential. Full article
(This article belongs to the Special Issue Sensing of Toxic and Hazardous Metals in Various Environmental Media)
Show Figures

Graphical abstract

1617 KiB  
Article
Design and Control of a Ferromagnetic Coded Micro-Carrier Biochip Sensor for Multiplex Detection of Antibodies
by Rong-Seng Chang, Jang-Zern Tsai and Tung-Yen Li
Sensors 2011, 11(8), 7851-7864; https://doi.org/10.3390/s110807851 - 11 Aug 2011
Cited by 9 | Viewed by 6949
Abstract
This paper describes a method for producing a novel type of ferromagnetic coded micro-carrier. The ferromagnetic coded micro-carriers are about 200 μm in length, 200 μm in width and 50 μm in thickness, and contain eight code elements with two distinguishable codes (hollow [...] Read more.
This paper describes a method for producing a novel type of ferromagnetic coded micro-carrier. The ferromagnetic coded micro-carriers are about 200 μm in length, 200 μm in width and 50 μm in thickness, and contain eight code elements with two distinguishable codes (hollow and solid), allowing for 28 unique codes. The code shapes include rectangle, circle, etc. Differently shaped coded micro-carriers could carry different antigens for detection of its complementary antibody. These many shapes of coded micro-carriers would be used simultaneously allowing us to make multiple detections for different antibodies at the same time. A molding process is applied for fabrication of the ferromagnetically coded micro-carriers where Fe material (Fe powder mixed with binder) is shaped in many tiny molds to produce the coded shapes used for identification of the bio-molecules. Magnetic force is used to control the movement and location of the ferromagnetic coded micro-carriers to prevent the loss during the hybridization process. The results of image process and analysis system testing are satisfactory. The results of our micro-carrier detection system for two sets of R and B color analysis are proportional to those obtained from ELISA antibody detection. Full article
(This article belongs to the Section Biosensors)
Show Figures

779 KiB  
Communication
Smart Learning Services Based on Smart Cloud Computing
by Svetlana Kim, Su-Mi Song and Yong-Ik Yoon
Sensors 2011, 11(8), 7835-7850; https://doi.org/10.3390/s110807835 - 09 Aug 2011
Cited by 86 | Viewed by 14758
Abstract
Context-aware technologies can make e-learning services smarter and more efficient since context-aware services are based on the user’s behavior. To add those technologies into existing e-learning services, a service architecture model is needed to transform the existing e-learning environment, which is situation-aware, into [...] Read more.
Context-aware technologies can make e-learning services smarter and more efficient since context-aware services are based on the user’s behavior. To add those technologies into existing e-learning services, a service architecture model is needed to transform the existing e-learning environment, which is situation-aware, into the environment that understands context as well. The context-awareness in e-learning may include the awareness of user profile and terminal context. In this paper, we propose a new notion of service that provides context-awareness to smart learning content in a cloud computing environment. We suggest the elastic four smarts (E4S)—smart pull, smart prospect, smart content, and smart push—concept to the cloud services so smart learning services are possible. The E4S focuses on meeting the users’ needs by collecting and analyzing users’ behavior, prospecting future services, building corresponding contents, and delivering the contents through cloud computing environment. Users’ behavior can be collected through mobile devices such as smart phones that have built-in sensors. As results, the proposed smart e-learning model in cloud computing environment provides personalized and customized learning services to its users. Full article
(This article belongs to the Special Issue Selected Papers from FGIT 2010)
Show Figures

Graphical abstract

266 KiB  
Article
A Study Using a Monte Carlo Method of the Optimal Configuration of a Distribution Network in Terms of Power Loss Sensing
by Hyun Ho Moon, Jong Joo Lee, Sang Yule Choi, Jae Sang Cha, Jang Mook Kang, Jong Tae Kim and Myong Chul Shin
Sensors 2011, 11(8), 7823-7834; https://doi.org/10.3390/s110807823 - 09 Aug 2011
Cited by 10 | Viewed by 9809
Abstract
Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that [...] Read more.
Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels—is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI's IntelliGrid research program. The European Union (EU), which represents Europe’s Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal design, which considers the distribution loss associated with power distribution systems focus on sensing aspect and distributed power generation. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

Graphical abstract

595 KiB  
Article
A Biomimetic Sensor for the Classification of Honeys of Different Floral Origin and the Detection of Adulteration
by Ammar Zakaria, Ali Yeon Md Shakaff, Maz Jamilah Masnan, Mohd Noor Ahmad, Abdul Hamid Adom, Mahmad Nor Jaafar, Supri A. Ghani, Abu Hassan Abdullah, Abdul Hallis Abdul Aziz, Latifah Munirah Kamarudin, Norazian Subari and Nazifah Ahmad Fikri
Sensors 2011, 11(8), 7799-7822; https://doi.org/10.3390/s110807799 - 09 Aug 2011
Cited by 76 | Viewed by 13815
Abstract
The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals [...] Read more.
The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals in honey, sugar adulterated honey is much trickier and harder to detect, and traditionally it has been very challenging to come up with a suitable method to prove the presence of adulterants in honey products. This paper proposes a combination of array sensing and multi-modality sensor fusion that can effectively discriminate the samples not only based on the compounds present in the sample but also mimic the way humans perceive flavours and aromas. Conversely, analytical instruments are based on chemical separations which may alter the properties of the volatiles or flavours of a particular honey. The present work is focused on classifying 18 samples of different honeys, sugar syrups and adulterated samples using data fusion of electronic nose (e-nose) and electronic tongue (e-tongue) measurements. Each group of samples was evaluated separately by the e-nose and e-tongue. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were able to separately discriminate monofloral honey from sugar syrup, and polyfloral honey from sugar and adulterated samples using the e-nose and e-tongue. The e-nose was observed to give better separation compared to e-tongue assessment, particularly when LDA was applied. However, when all samples were combined in one classification analysis, neither PCA nor LDA were able to discriminate between honeys of different floral origins, sugar syrup and adulterated samples. By applying a sensor fusion technique, the classification for the 18 different samples was improved. Significant improvement was observed using PCA, while LDA not only improved the discrimination but also gave better classification. An improvement in performance was also observed using a Probabilistic Neural Network classifier when the e-nose and e-tongue data were fused. Full article
(This article belongs to the Special Issue Bioinspired Sensor Systems)
Show Figures

1470 KiB  
Review
A Review of Optical NDT Technologies
by Yong-Kai Zhu, Gui-Yun Tian, Rong-Sheng Lu and Hong Zhang
Sensors 2011, 11(8), 7773-7798; https://doi.org/10.3390/s110807773 - 08 Aug 2011
Cited by 197 | Viewed by 17435
Abstract
Optical non-destructive testing (NDT) has gained more and more attention in recent years, mainly because of its non-destructive imaging characteristics with high precision and sensitivity. This paper provides a review of the main optical NDT technologies, including fibre optics, electronic speckle, infrared thermography, [...] Read more.
Optical non-destructive testing (NDT) has gained more and more attention in recent years, mainly because of its non-destructive imaging characteristics with high precision and sensitivity. This paper provides a review of the main optical NDT technologies, including fibre optics, electronic speckle, infrared thermography, endoscopic and terahertz technology. Among them, fibre optics features easy integration and embedding, electronic speckle focuses on whole-field high precision detection, infrared thermography has unique advantages for tests of combined materials, endoscopic technology provides images of the internal surface of the object directly, and terahertz technology opens a new direction of internal NDT because of its excellent penetration capability to most of non-metallic materials. Typical engineering applications of these technologies are illustrated, with a brief introduction of the history and discussion of recent progress. Full article
(This article belongs to the Section Physical Sensors)
Show Figures

1120 KiB  
Article
A Single-Walled Carbon Nanotube Network Gas Sensing Device
by Li-Chun Wang, Kea-Tiong Tang, I-Ju Teng, Cheng-Tzu Kuo, Cheng-Long Ho, Han-Wen Kuo, Tseng-Hsiung Su, Shang-Ren Yang, Gia-Nan Shi and Chang-Ping Chang
Sensors 2011, 11(8), 7763-7772; https://doi.org/10.3390/s110807763 - 08 Aug 2011
Cited by 49 | Viewed by 9880
Abstract
The goal of this research was to develop a chemical gas sensing device based on single-walled carbon nanotube (SWCNT) networks. The SWCNT networks are synthesized on Al2O3-deposted SiO2/Si substrates with 10 nm-thick Fe as the catalyst precursor [...] Read more.
The goal of this research was to develop a chemical gas sensing device based on single-walled carbon nanotube (SWCNT) networks. The SWCNT networks are synthesized on Al2O3-deposted SiO2/Si substrates with 10 nm-thick Fe as the catalyst precursor layer using microwave plasma chemical vapor deposition (MPCVD). The development of interconnected SWCNT networks can be exploited to recognize the identities of different chemical gases by the strength of their particular surface adsorptive and desorptive responses to various types of chemical vapors. The physical responses on the surface of the SWCNT networks cause superficial changes in the electric charge that can be converted into electronic signals for identification. In this study, we tested NO2 and NH3 vapors at ppm levels at room temperature with our self-made gas sensing device, which was able to obtain responses to sensitivity changes with a concentration of 10 ppm for NO2 and 24 ppm for NH3. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

1927 KiB  
Article
A Renewable and Ultrasensitive Electrochemiluminescence Immunosenor Based on Magnetic RuL@SiO2-Au~RuL-Ab2 Sandwich-Type Nano-Immunocomplexes
by Ning Gan, Jianguo Hou, Futao Hu, Yuting Cao, Tianhua Li, Zhiyong Guo and Jun Wang
Sensors 2011, 11(8), 7749-7762; https://doi.org/10.3390/s110807749 - 05 Aug 2011
Cited by 10 | Viewed by 8803
Abstract
An ultrasensitive and renewable electrochemiluminescence (ECL) immunosensor was developed for the detection of tumor markers by combining a newly designed trace tag and streptavidin-coated magnetic particles (SCMPs). The trace tag (RuL@SiO2-Au~RuL-Ab2) was prepared by loading Ru(bpy)32+(RuL)-conjuged secondary antibodies [...] Read more.
An ultrasensitive and renewable electrochemiluminescence (ECL) immunosensor was developed for the detection of tumor markers by combining a newly designed trace tag and streptavidin-coated magnetic particles (SCMPs). The trace tag (RuL@SiO2-Au~RuL-Ab2) was prepared by loading Ru(bpy)32+(RuL)-conjuged secondary antibodies (RuL-Ab2) on RuL@SiO2 (RuL-doped SiO2) doped Au (RuL@SiO2-Au). To fabricate the immunosensor, SCMPs were mixed with biotinylated AFP primary antibody (Biotin-Ab1), AFP, and RuL@SiO2-Au~RuL-Ab2 complexes, then the resulting SCMP/Biotin-Ab1/AFP/RuL@SiO2-Au~RuL-Ab2 (SBAR) sandwich-type immunocomplexes were absorbed on screen printed carbon electrode (SPCE) for detection. The immunocomplexes can be easily washed away from the surface of the SPCE when the magnetic field was removed, which made the immunosensor reusable. The present immunosensor showed a wide linear range of 0.05–100 ng mL–1 for detecting AFP, with a low detection limit of 0.02 ng mL–1 (defined as S/N = 3). The method takes advantage of three properties of the immunosensor: firstly, the RuL@SiO2-Au~RuL-Ab2 composite exhibited dual amplification since SiO2 could load large amount of reporter molecules (RuL) for signal amplification. Gold particles could provide a large active surface to load more reporter molecules (RuL-Ab2). Accordingly, through the ECL response of RuL and tripropylamine (TPA), a strong ECL signal was obtained and an amplification analysis of protein interaction was achieved. Secondly, the sensor is renewable because the sandwich-type immunocomplexes can be readily absorbed or removed on the SPCE’s surface in a magnetic field. Thirdly, the SCMP modified probes can perform the rapid separation and purification of signal antibodies in a magnetic field. Thus, the present immunosensor can simultaneously realize separation, enrichment and determination. It showed potential application for the detection of AFP in human sera. Full article
(This article belongs to the Section Biosensors)
Show Figures

2331 KiB  
Article
Planar Zeolite Film-Based Potentiometric Gas Sensors Manufactured by a Combined Thick-Film and Electroplating Technique
by Isabella Marr, Sebastian Reiß, Gunter Hagen and Ralf Moos
Sensors 2011, 11(8), 7736-7748; https://doi.org/10.3390/s110807736 - 05 Aug 2011
Cited by 16 | Viewed by 8246
Abstract
Zeolites are promising materials in the field of gas sensors. In this technology-oriented paper, a planar setup for potentiometric hydrocarbon and hydrogen gas sensors using zeolites as ionic sodium conductors is presented, in which the Pt-loaded Na-ZSM-5 zeolite is applied using a thick-film [...] Read more.
Zeolites are promising materials in the field of gas sensors. In this technology-oriented paper, a planar setup for potentiometric hydrocarbon and hydrogen gas sensors using zeolites as ionic sodium conductors is presented, in which the Pt-loaded Na-ZSM-5 zeolite is applied using a thick-film technique between two interdigitated gold electrodes and one of them is selectively covered for the first time by an electroplated chromium oxide film. The influence of the sensor temperature, the type of hydrocarbons, the zeolite film thickness, and the chromium oxide film thickness is investigated. The influence of the zeolite on the sensor response is briefly discussed in the light of studies dealing with zeolites as selectivity-enhancing cover layers. Full article
(This article belongs to the Section Chemical Sensors)
Show Figures

1777 KiB  
Article
SnO2/Pt Thin Film Laser Ablated Gas Sensor Array
by Mohammad Hadi Shahrokh Abadi, Mohd Nizar Hamidon, Abdul Halim Shaari, Norhafizah Abdullah and Rahman Wagiran
Sensors 2011, 11(8), 7724-7735; https://doi.org/10.3390/s110807724 - 05 Aug 2011
Cited by 25 | Viewed by 9770
Abstract
A gas sensor array was developed in a 10 × 10 mm2 space using Screen Printing and Pulse Laser Ablation Deposition (PLAD) techniques. Heater, electrode, and an insulator interlayer were printed using the screen printing method on an alumina substrate, while tin [...] Read more.
A gas sensor array was developed in a 10 × 10 mm2 space using Screen Printing and Pulse Laser Ablation Deposition (PLAD) techniques. Heater, electrode, and an insulator interlayer were printed using the screen printing method on an alumina substrate, while tin oxide and platinum films, as sensing and catalyst layers, were deposited on the electrode at room temperature using the PLAD method, respectively. To ablate SnO2 and Pt targets, depositions were achieved by using a 1,064 nm Nd-YAG laser, with a power of 0.7 J/s, at different deposition times of 2, 5 and 10 min, in an atmosphere containing 0.04 mbar (4 kPa) of O2. A range of spectroscopic diffraction and real space imaging techniques, SEM, EDX, XRD, and AFM were used in order to characterize the surface morphology, structure, and composition of the films. Measurement on the array shows sensitivity to some solvent and wood smoke can be achieved with short response and recovery times. Full article
(This article belongs to the Special Issue Semiconductor Sensors)
Show Figures

Graphical abstract

Previous Issue
Back to TopTop