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Sensors, Volume 14, Issue 11 (November 2014) , Pages 19926-22158

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Open AccessArticle
Accurate Monitoring and Fault Detection in Wind Measuring Devices through Wireless Sensor Networks
Sensors 2014, 14(11), 22140-22158; https://doi.org/10.3390/s141122140
Received: 25 July 2014 / Revised: 30 September 2014 / Accepted: 21 October 2014 / Published: 24 November 2014
Cited by 2 | Viewed by 2498 | PDF Full-text (1259 KB) | HTML Full-text | XML Full-text
Abstract
Many wind energy projects report poor performance as low as 60% of the predicted performance. The reason for this is poor resource assessment and the use of new untested technologies and systems in remote locations. Predictions about the potential of an area for [...] Read more.
Many wind energy projects report poor performance as low as 60% of the predicted performance. The reason for this is poor resource assessment and the use of new untested technologies and systems in remote locations. Predictions about the potential of an area for wind energy projects (through simulated models) may vary from the actual potential of the area. Hence, introducing accurate site assessment techniques will lead to accurate predictions of energy production from a particular area. We solve this problem by installing a Wireless Sensor Network (WSN) to periodically analyze the data from anemometers installed in that area. After comparative analysis of the acquired data, the anemometers transmit their readings through a WSN to the sink node for analysis. The sink node uses an iterative algorithm which sequentially detects any faulty anemometer and passes the details of the fault to the central system or main station. We apply the proposed technique in simulation as well as in practical implementation and study its accuracy by comparing the simulation results with experimental results to analyze the variation in the results obtained from both simulation model and implemented model. Simulation results show that the algorithm indicates faulty anemometers with high accuracy and low false alarm rate when as many as 25% of the anemometers become faulty. Experimental analysis shows that anemometers incorporating this solution are better assessed and performance level of implemented projects is increased above 86% of the simulated models. Full article
(This article belongs to the Special Issue Wireless Sensor Networks and the Internet of Things)
Open AccessArticle
Novel Membrane-Based Electrochemical Sensor for Real-Time Bio-Applications
Sensors 2014, 14(11), 22128-22139; https://doi.org/10.3390/s141122128
Received: 30 July 2014 / Revised: 4 November 2014 / Accepted: 14 November 2014 / Published: 24 November 2014
Cited by 12 | Viewed by 2316 | PDF Full-text (1624 KB) | HTML Full-text | XML Full-text
Abstract
This article presents a novel membrane-based sensor for real-time electrochemical investigations of cellular- or tissue cultures. The membrane sensor enables recording of electrical signals from a cell culture without any signal dilution, thus avoiding loss of sensitivity. Moreover, the porosity of the membrane [...] Read more.
This article presents a novel membrane-based sensor for real-time electrochemical investigations of cellular- or tissue cultures. The membrane sensor enables recording of electrical signals from a cell culture without any signal dilution, thus avoiding loss of sensitivity. Moreover, the porosity of the membrane provides optimal culturing conditions similar to existing culturing techniques allowing more efficient nutrient uptake and molecule release. The patterned sensor electrodes were fabricated on a porous membrane by electron-beam evaporation. The electrochemical performance of the membrane electrodes was characterized by cyclic voltammetry and chronoamperometry, and the detection of synthetic dopamine was demonstrated down to a concentration of 3.1 pM. Furthermore, to present the membrane-sensor functionality the dopamine release from cultured PC12 cells was successfully measured. The PC12 cells culturing experiments showed that the membrane-sensor was suitable as a cell culturing substrate for bio-applications. Real-time measurements of dopamine exocytosis in cell cultures were performed, where the transmitter release was recorded at the point of release. The developed membrane-sensor provides a new functionality to the standard culturing methods, enabling sensitive continuous in vitro monitoring and closely mimicking the in vivo conditions. Full article
(This article belongs to the Section Biosensors)
Open AccessArticle
A System for Traffic Violation Detection
Sensors 2014, 14(11), 22113-22127; https://doi.org/10.3390/s141122113
Received: 10 June 2014 / Revised: 28 October 2014 / Accepted: 13 November 2014 / Published: 24 November 2014
Cited by 5 | Viewed by 2638 | PDF Full-text (663 KB) | HTML Full-text | XML Full-text
Abstract
This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS) aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic [...] Read more.
This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS) aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic violations, record data associated to these faults in a local data-base, and also allow visualization of the spatial and temporal information of these traffic violations in a geographical map using the standard Google Earth tool. The test-bed is mainly composed of two parts: a computer vision subsystem for traffic sign detection and recognition which operates during both day and nighttime, and an event data recorder (EDR) for recording data related to some specific traffic violations. The paper covers firstly the description of the hardware architecture and then presents the policies used for handling traffic violations. Full article
(This article belongs to the Special Issue Positioning and Tracking Sensors and Technologies in Road Transport)
Open AccessArticle
Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range
Sensors 2014, 14(11), 22099-22112; https://doi.org/10.3390/s141122099
Received: 23 April 2014 / Revised: 11 November 2014 / Accepted: 13 November 2014 / Published: 21 November 2014
Cited by 2 | Viewed by 2457 | PDF Full-text (990 KB) | HTML Full-text | XML Full-text
Abstract
In this study, we develop a clamped–clamped beam-type piezoelectric vacuum pressure sensing element. The clamped–clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a [...] Read more.
In this study, we develop a clamped–clamped beam-type piezoelectric vacuum pressure sensing element. The clamped–clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10−6 to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage. Full article
(This article belongs to the Special Issue Sensors for Fluid Leak Detection) Printed Edition available
Open AccessArticle
Overcoming the Challenges of BeiDou Receiver Implementation
Sensors 2014, 14(11), 22082-22098; https://doi.org/10.3390/s141122082
Received: 26 August 2014 / Revised: 26 September 2014 / Accepted: 12 November 2014 / Published: 21 November 2014
Cited by 21 | Viewed by 2331 | PDF Full-text (1353 KB) | HTML Full-text | XML Full-text
Abstract
Global Navigation Satellite System (GNSS)-based positioning is experiencing rapid changes. The existing GPS and the GLONASS systems are being modernized to better serve the current challenging applications under harsh signal conditions. These modernizations include increasing the number of transmission frequencies and changes to [...] Read more.
Global Navigation Satellite System (GNSS)-based positioning is experiencing rapid changes. The existing GPS and the GLONASS systems are being modernized to better serve the current challenging applications under harsh signal conditions. These modernizations include increasing the number of transmission frequencies and changes to the signal components. In addition, the Chinese BeiDou Navigation Satellite system (BDS) and the European Galileo are currently under development for global operation. Therefore, in view of these new upcoming systems the research and development of GNSS receivers has been experiencing a new upsurge. In this article, the authors discuss the main functionalities of a GNSS receiver in view of BDS. While describing the main functionalities of a software-defined BeiDou receiver, the authors also highlight the similarities and differences between the signal characteristics of the BeiDou B1 open service signal and the legacy GPS L1 C/A signal, as in general they both exhibit similar characteristics. In addition, the authors implement a novel acquisition technique for long coherent integration in the presence of NH code modulation in BeiDou D1 signal. Furthermore, a simple phase-preserved coherent integration based acquisition scheme is implemented for BeiDou GEO satellite acquisition. Apart from the above BeiDou-specific implementations, a novel Carrier-to-Noise-density ratio estimation technique is also implemented in the software receiver, which does not necessarily require bit synchronization prior to estimation. Finally, the authors present a BeiDou-only position fix with the implemented software-defined BeiDou receiver considering all three satellite constellations from BDS. In addition, a true multi-GNSS position fix with GPS and BDS systems is also presented while comparing their performances for a static stand-alone code phase-based positioning. Full article
(This article belongs to the Section Remote Sensors, Control, and Telemetry)
Open AccessArticle
Development of a Personal Integrated Environmental Monitoring System
Sensors 2014, 14(11), 22065-22081; https://doi.org/10.3390/s141122065
Received: 16 July 2014 / Revised: 23 September 2014 / Accepted: 14 November 2014 / Published: 20 November 2014
Cited by 6 | Viewed by 2829 | PDF Full-text (1880 KB) | HTML Full-text | XML Full-text
Abstract
Environmental pollution in the urban areas of Hong Kong has become a serious public issue but most urban inhabitants have no means of judging their own living environment in terms of dangerous threshold and overall livability. Currently there exist many low-cost sensors such [...] Read more.
Environmental pollution in the urban areas of Hong Kong has become a serious public issue but most urban inhabitants have no means of judging their own living environment in terms of dangerous threshold and overall livability. Currently there exist many low-cost sensors such as ultra-violet, temperature and air quality sensors that provide reasonably accurate data quality. In this paper, the development and evaluation of Integrated Environmental Monitoring System (IEMS) are illustrated. This system consists of three components: (i) position determination and sensor data collection for real-time geospatial-based environmental monitoring; (ii) on-site data communication and visualization with the aid of an Android-based application; and (iii) data analysis on a web server. This system has shown to be working well during field tests in a bus journey and a construction site. It provides an effective service platform for collecting environmental data in near real-time, and raises the public awareness of environmental quality in micro-environments. Full article
(This article belongs to the Section Remote Sensors, Control, and Telemetry)
Open AccessArticle
IoT-Based User-Driven Service Modeling Environment for a Smart Space Management System
Sensors 2014, 14(11), 22039-22064; https://doi.org/10.3390/s141122039
Received: 5 September 2014 / Revised: 10 November 2014 / Accepted: 13 November 2014 / Published: 20 November 2014
Cited by 10 | Viewed by 3991 | PDF Full-text (2531 KB) | HTML Full-text | XML Full-text
Abstract
The existing Internet environment has been extended to the Internet of Things (IoT) as an emerging new paradigm. The IoT connects various physical entities. These entities have communication capability and deploy the observed information to various service areas such as building management, energy-saving [...] Read more.
The existing Internet environment has been extended to the Internet of Things (IoT) as an emerging new paradigm. The IoT connects various physical entities. These entities have communication capability and deploy the observed information to various service areas such as building management, energy-saving systems, surveillance services, and smart homes. These services are designed and developed by professional service providers. Moreover, users’ needs have become more complicated and personalized with the spread of user-participation services such as social media and blogging. Therefore, some active users want to create their own services to satisfy their needs, but the existing IoT service-creation environment is difficult for the non-technical user because it requires a programming capability to create a service. To solve this problem, we propose the IoT-based user-driven service modeling environment to provide an easy way to create IoT services. Also, the proposed environment deploys the defined service to another user. Through the personalization and customization of the defined service, the value and dissemination of the service is increased. This environment also provides the ontology-based context-information processing that produces and describes the context information for the IoT-based user-driven service. Full article
(This article belongs to the Special Issue Wireless Sensor Networks and the Internet of Things)
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Open AccessArticle
Design of a Novel Flexible Capacitive Sensing Mattress for Monitoring Sleeping Respiratory
Sensors 2014, 14(11), 22021-22038; https://doi.org/10.3390/s141122021
Received: 5 September 2014 / Revised: 3 November 2014 / Accepted: 4 November 2014 / Published: 20 November 2014
Cited by 5 | Viewed by 2778 | PDF Full-text (1428 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, an algorithm to extract respiration signals using a flexible projected capacitive sensing mattress (FPCSM) designed for personal health assessment is proposed. Unlike the interfaces of conventional measurement systems for poly-somnography (PSG) and other alternative contemporary systems, the proposed FPCSM uses [...] Read more.
In this paper, an algorithm to extract respiration signals using a flexible projected capacitive sensing mattress (FPCSM) designed for personal health assessment is proposed. Unlike the interfaces of conventional measurement systems for poly-somnography (PSG) and other alternative contemporary systems, the proposed FPCSM uses projected capacitive sensing capability that is not worn or attached to the body. The FPCSM is composed of a multi-electrode sensor array that can not only observe gestures and motion behaviors, but also enables the FPCSM to function as a respiration monitor during sleep using the proposed approach. To improve long-term monitoring when body movement is possible, the FPCSM enables the selection of data from the sensing array, and the FPCSM methodology selects the electrodes with the optimal signals after the application of a channel reduction algorithm that counts the reversals in the capacitive sensing signals as a quality indicator. The simple algorithm is implemented in the time domain. The FPCSM system is used in experimental tests and is simultaneously compared with a commercial PSG system for verification. Multiple synchronous measurements are performed from different locations of body contact, and parallel data sets are collected. The experimental comparison yields a correlation coefficient of 0.88 between FPCSM and PSG, demonstrating the feasibility of the system design. Full article
(This article belongs to the collection Sensors for Globalized Healthy Living and Wellbeing)
Open AccessArticle
Behavior Life Style Analysis for Mobile Sensory Data in Cloud Computing through MapReduce
Sensors 2014, 14(11), 22001-22020; https://doi.org/10.3390/s141122001
Received: 1 January 2014 / Revised: 4 November 2014 / Accepted: 12 November 2014 / Published: 20 November 2014
Cited by 15 | Viewed by 3270 | PDF Full-text (411 KB) | HTML Full-text | XML Full-text
Abstract
Cloud computing has revolutionized healthcare in today’s world as it can be seamlessly integrated into a mobile application and sensor devices. The sensory data is then transferred from these devices to the public and private clouds. In this paper, a hybrid and distributed [...] Read more.
Cloud computing has revolutionized healthcare in today’s world as it can be seamlessly integrated into a mobile application and sensor devices. The sensory data is then transferred from these devices to the public and private clouds. In this paper, a hybrid and distributed environment is built which is capable of collecting data from the mobile phone application and store it in the cloud. We developed an activity recognition application and transfer the data to the cloud for further processing. Big data technology Hadoop MapReduce is employed to analyze the data and create user timeline of user’s activities. These activities are visualized to find useful health analytics and trends. In this paper a big data solution is proposed to analyze the sensory data and give insights into user behavior and lifestyle trends. Full article
(This article belongs to the Special Issue Sensors Data Fusion for Healthcare)
Open AccessArticle
Off-Grid Direction of Arrival Estimation Based on Joint Spatial Sparsity for Distributed Sparse Linear Arrays
Sensors 2014, 14(11), 21981-22000; https://doi.org/10.3390/s141121981
Received: 28 August 2014 / Revised: 24 October 2014 / Accepted: 13 November 2014 / Published: 20 November 2014
Cited by 8 | Viewed by 2613 | PDF Full-text (6067 KB) | HTML Full-text | XML Full-text
Abstract
In the design phase of sensor arrays during array signal processing, the estimation performance and system cost are largely determined by array aperture size. In this article, we address the problem of joint direction-of-arrival (DOA) estimation with distributed sparse linear arrays (SLAs) and [...] Read more.
In the design phase of sensor arrays during array signal processing, the estimation performance and system cost are largely determined by array aperture size. In this article, we address the problem of joint direction-of-arrival (DOA) estimation with distributed sparse linear arrays (SLAs) and propose an off-grid synchronous approach based on distributed compressed sensing to obtain larger array aperture. We focus on the complex source distribution in the practical applications and classify the sources into common and innovation parts according to whether a signal of source can impinge on all the SLAs or a specific one. For each SLA, we construct a corresponding virtual uniform linear array (ULA) to create the relationship of random linear map between the signals respectively observed by these two arrays. The signal ensembles including the common/innovation sources for different SLAs are abstracted as a joint spatial sparsity model. And we use the minimization of concatenated atomic norm via semidefinite programming to solve the problem of joint DOA estimation. Joint calculation of the signals observed by all the SLAs exploits their redundancy caused by the common sources and decreases the requirement of array size. The numerical results illustrate the advantages of the proposed approach. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle
Raman Imaging with a Fiber-Coupled Multichannel Spectrograph
Sensors 2014, 14(11), 21968-21980; https://doi.org/10.3390/s141121968
Received: 24 September 2014 / Revised: 4 November 2014 / Accepted: 11 November 2014 / Published: 20 November 2014
Cited by 21 | Viewed by 2982 | PDF Full-text (2154 KB) | HTML Full-text | XML Full-text
Abstract
Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of an entire Raman image with only one single exposure. The Raman scattering arising from [...] Read more.
Until now, spatially resolved Raman Spectroscopy has required to scan a sample under investigation in a time-consuming step-by-step procedure. Here, we present a technique that allows the capture of an entire Raman image with only one single exposure. The Raman scattering arising from the sample was collected with a fiber-coupled high-performance astronomy spectrograph. The probe head consisting of an array of 20 × 20 multimode fibers was linked to the camera port of a microscope. To demonstrate the high potential of this new concept, Raman images of reference samples were recorded. Entire chemical maps were received without the need for a scanning procedure. Full article
(This article belongs to the Section Physical Sensors)
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Graphical abstract

Open AccessArticle
A Combined Method for Segmentation and Registration for an Advanced and Progressive Evaluation of Thermal Images
Sensors 2014, 14(11), 21950-21967; https://doi.org/10.3390/s141121950
Received: 18 July 2014 / Revised: 25 October 2014 / Accepted: 6 November 2014 / Published: 19 November 2014
Cited by 9 | Viewed by 3394 | PDF Full-text (15339 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian [...] Read more.
In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian professional soccer club. The goal is to produce information on spatio-temporal variations of thermograms favoring the investigation of the athletes’ conditions along the competition. The proposed method improves on current practice by providing a means for automatically detecting adaptive body-shaped regions of interest, instead of the manual selection of simple shapes. Specifically, our approach combines the optimization features in Otsu’s method with a correction factor and post-processing techniques, enhancing thermal-image segmentation when compared to other methods. Additional contributions resulting from the combination of the segmentation and registration steps of our approach are the progressive analyses of thermograms in a unique spatial coordinate system and the accurate extraction of measurements and isotherms. Full article
(This article belongs to the Section Physical Sensors)
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Graphical abstract

Open AccessArticle
The Coefficient of the Voltage Induced Frequency Shift Measurement on a Quartz Tuning Fork
Sensors 2014, 14(11), 21941-21949; https://doi.org/10.3390/s141121941
Received: 10 September 2014 / Revised: 22 October 2014 / Accepted: 12 November 2014 / Published: 19 November 2014
Viewed by 2470 | PDF Full-text (4910 KB) | HTML Full-text | XML Full-text
Abstract
We have measured the coefficient of the voltage induced frequency shift (VIFS) of a 32.768 KHz quartz tuning fork. Three vibration modes were studied: one prong oscillating, two prongs oscillating in the same direction, and two prongs oscillating in opposite directions. They all [...] Read more.
We have measured the coefficient of the voltage induced frequency shift (VIFS) of a 32.768 KHz quartz tuning fork. Three vibration modes were studied: one prong oscillating, two prongs oscillating in the same direction, and two prongs oscillating in opposite directions. They all showed a parabolic dependence of the eigen-frequency shift on the bias voltage applied across the fork, due to the voltage-induced internal stress, which varies as the fork oscillates. The average coefficient of the VIFS effect is as low as several hundred nano-Hz per millivolt, implying that fast-response voltage-controlled oscillators and phase-locked loops with nano-Hz resolution can be built. Full article
(This article belongs to the Section Physical Sensors)
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Graphical abstract

Open AccessArticle
Dual Resonant Frequencies Effects on an Induction-Based Oil Palm Fruit Sensor
Sensors 2014, 14(11), 21923-21940; https://doi.org/10.3390/s141121923
Received: 3 September 2014 / Revised: 27 October 2014 / Accepted: 6 November 2014 / Published: 19 November 2014
Cited by 4 | Viewed by 2124 | PDF Full-text (1110 KB) | HTML Full-text | XML Full-text
Abstract
As the main exporter in the oil palm industry, the need to improve the quality of palm oil has become the main interest among all the palm oil millers in Malaysia. To produce good quality palm oil, it is important for the miller [...] Read more.
As the main exporter in the oil palm industry, the need to improve the quality of palm oil has become the main interest among all the palm oil millers in Malaysia. To produce good quality palm oil, it is important for the miller to harvest a good oil palm Fresh Fruit Bunch (FFB). Conventionally, the main reference used by Malaysian harvesters is the manual grading standard published by the Malaysian Palm Oil Board (MPOB). A good oil palm FFB consists of all matured fruitlets, aged between 18 to 21 weeks of antheses (WAA). To expedite the harvesting process, it is crucial to implement an automated detection system for determining the maturity of the oil palm FFB. Various automated detection methods have been proposed by researchers in the field to replace the conventional method. In our preliminary study, a novel oil palm fruit sensor to detect the maturity of oil palm fruit bunch was proposed. The design of the proposed air coil sensor based on the inductive sensor was further investigated mainly in the context of the effect of coil diameter to improve its sensitivity. In this paper, the sensitivity of the inductive sensor was further examined with a dual flat-type shape of air coil. The dual air coils were tested on fifteen samples of fruitlet from two categories, namely ripe and unripe. Samples were tested within 20 Hz to 10 MHz while evaluations on both peaks were done separately before the gap between peaks was analyzed. A comparative analysis was conducted to investigate the improvement in sensitivity of the induction-based oil palm fruit sensor as compared to previous works. Results from the comparative study proved that the inductive sensor using a dual flat-type shape air coil has improved by up to 167%. This provides an indication in the improvement in the coil sensitivity of the palm oil fruit sensor based on the induction concept. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle
Cobalt Phthalocyanine Modified Electrodes Utilised in Electroanalysis: Nano-Structured Modified Electrodes vs. Bulk Modified Screen-Printed Electrodes
Sensors 2014, 14(11), 21905-21922; https://doi.org/10.3390/s141121905
Received: 26 May 2014 / Revised: 17 October 2014 / Accepted: 6 November 2014 / Published: 19 November 2014
Cited by 39 | Viewed by 2747 | PDF Full-text (3377 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated [...] Read more.
Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC) onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no “electrocatalysis” is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where “electrocatalysis” has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate. Full article
(This article belongs to the Special Issue Printed Sensors)
Open AccessArticle
The Benefit of 3D Laser Scanning Technology in the Generation and Calibration of FEM Models for Health Assessment of Concrete Structures
Sensors 2014, 14(11), 21889-21904; https://doi.org/10.3390/s141121889
Received: 29 August 2014 / Revised: 28 October 2014 / Accepted: 10 November 2014 / Published: 19 November 2014
Cited by 26 | Viewed by 2684 | PDF Full-text (2155 KB) | HTML Full-text | XML Full-text
Abstract
Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D [...] Read more.
Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle
Rapid Detection of Chloramphenicol Residues in Aquatic Products Using Colloidal Gold Immunochromatographic Assay
Sensors 2014, 14(11), 21872-21888; https://doi.org/10.3390/s141121872
Received: 30 July 2014 / Revised: 15 September 2014 / Accepted: 4 November 2014 / Published: 18 November 2014
Cited by 11 | Viewed by 2990 | PDF Full-text (2757 KB) | HTML Full-text | XML Full-text
Abstract
A colloidal gold immunochromatographic assay (GICA) was developed for rapid detection of chloramphenicol (CAP) residues in aquatic products. A nitrocellulose (NC) membrane was used as the carrier, and the polyclonal CAP antibody was used as the marker protein. The average diameter of as-prepared [...] Read more.
A colloidal gold immunochromatographic assay (GICA) was developed for rapid detection of chloramphenicol (CAP) residues in aquatic products. A nitrocellulose (NC) membrane was used as the carrier, and the polyclonal CAP antibody was used as the marker protein. The average diameter of as-prepared colloidal gold nanoparticles (AuNPs) was about 20 nm. The optimal pH value of colloidal gold solutions and the amount of the antibody of CAP were 8.0 and 7.2 μg/mL, respectively. The CAP antibody was immobilized onto the conjugate pad after purification. The CAP conjugate and goat anti-rabbit IgG (secondary antibody) were coated onto the NC membrane. Next, the non-specific sites were blocked with 1% bovine serum albumin. The minimum detectable concentration of CAP in standard solution is 0.5 ng/mL, with good reproducibility. For the real samples from crucian carps injected with a single-dose of CAP in the dorsal muscles, the minimum detectable concentration of CAP residues was 0.5 µg/kg. The chromatographic analysis time was less than 10 min, and the strip had a long storage lifetime of more than 90 days at different temperatures. The strips provide a means for rapid detection of CAP residues in aquatic products. Full article
(This article belongs to the Special Issue Immunosensors 2014)
Open AccessArticle
A Sub-Clustering Algorithm Based on Spatial Data Correlation for Energy Conservation in Wireless Sensor Networks
Sensors 2014, 14(11), 21858-21871; https://doi.org/10.3390/s141121858
Received: 8 September 2014 / Revised: 27 October 2014 / Accepted: 12 November 2014 / Published: 18 November 2014
Cited by 3 | Viewed by 2042 | PDF Full-text (1455 KB) | HTML Full-text | XML Full-text
Abstract
Wireless sensor networks (WSNs) have emerged as a promising solution for various applications due to their low cost and easy deployment. Typically, their limited power capability, i.e., battery powered, make WSNs encounter the challenge of extension of network lifetime. Many hierarchical protocols [...] Read more.
Wireless sensor networks (WSNs) have emerged as a promising solution for various applications due to their low cost and easy deployment. Typically, their limited power capability, i.e., battery powered, make WSNs encounter the challenge of extension of network lifetime. Many hierarchical protocols show better ability of energy efficiency in the literature. Besides, data reduction based on the correlation of sensed readings can efficiently reduce the amount of required transmissions. Therefore, we use a sub-clustering procedure based on spatial data correlation to further separate the hierarchical (clustered) architecture of a WSN. The proposed algorithm (2TC-cor) is composed of two procedures: the prediction model construction procedure and the sub-clustering procedure. The energy conservation benefits by the reduced transmissions, which are dependent on the prediction model. Also, the energy can be further conserved because of the representative mechanism of sub-clustering. As presented by simulation results, it shows that 2TC-cor can effectively conserve energy and monitor accurately the environment within an acceptable level. Full article
(This article belongs to the Section Sensor Networks)
Open AccessArticle
Rapid Immunoenzyme Assay of Aflatoxin B1 Using Magnetic Nanoparticles
Sensors 2014, 14(11), 21843-21857; https://doi.org/10.3390/s141121843
Received: 29 September 2014 / Revised: 5 November 2014 / Accepted: 14 November 2014 / Published: 18 November 2014
Cited by 22 | Viewed by 2795 | PDF Full-text (843 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The main limitations of microplate-based enzyme immunoassays are the prolonged incubations necessary to facilitate heterogeneous interactions, the complex matrix and poorly soluble antigens, and the significant sample dilutions often required because of the presence of organic extractants. This study presents the use of [...] Read more.
The main limitations of microplate-based enzyme immunoassays are the prolonged incubations necessary to facilitate heterogeneous interactions, the complex matrix and poorly soluble antigens, and the significant sample dilutions often required because of the presence of organic extractants. This study presents the use of antibody immobilization on the surface of magnetic particles to overcome these limitations in the detection of the mycotoxin, aflatoxin B1. Features of the proposed system are a high degree of nanoparticle dispersion and methodologically simple immobilization of the antibodies by adsorption. Reactions between the immobilized antibodies with native and labeled antigens are conducted in solution, thereby reducing the interaction period to 5 min without impairing the analytical outcome. Adsorption of immunoglobulins on the surface of magnetic nanoparticles increases their stability in aqueous-organic media, thus minimizing the degree of sample dilution required. Testing barley and maize extracts demonstrated a limit of aflatoxin B1 detection equal to 20 pg/mL and total assay duration of 20 min. Using this method, only the 3-fold dilution of the initial methanol/water (60/40) extraction mixture in the microplate wells is necessary. The proposed pseudo-homogeneous approach could be applied toward immunodetection of a wide range of compounds. Full article
(This article belongs to the Special Issue Nanoparticle-Based Biosensors)
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Open AccessArticle
Design of a WSN for the Sampling of Environmental Variability in Complex Terrain
Sensors 2014, 14(11), 21826-21842; https://doi.org/10.3390/s141121826
Received: 14 July 2014 / Revised: 28 October 2014 / Accepted: 12 November 2014 / Published: 18 November 2014
Cited by 1 | Viewed by 2200 | PDF Full-text (9595 KB) | HTML Full-text | XML Full-text
Abstract
In-situ environmental parameter measurements using sensor systems connected to a wireless network have become widespread, but the problem of monitoring large and mountainous areas by means of a wireless sensor network (WSN) is not well resolved. The main reasons for this are: (1) [...] Read more.
In-situ environmental parameter measurements using sensor systems connected to a wireless network have become widespread, but the problem of monitoring large and mountainous areas by means of a wireless sensor network (WSN) is not well resolved. The main reasons for this are: (1) the environmental variability distribution is unknown in the field; (2) without this knowledge, a huge number of sensors would be necessary to ensure the complete coverage of the environmental variability and (3) WSN design requirements, for example, effective connectivity (intervisibility), limiting distances and controlled redundancy, are usually solved by trial and error. Using temperature as the target environmental variable, we propose: (1) a method to determine the homogeneous environmental classes to be sampled using the digital elevation model (DEM) and geometric simulations and (2) a procedure to determine an effective WSN design in complex terrain in terms of the number of sensors, redundancy, cost and spatial distribution. The proposed methodology, based on geographic information systems and binary integer programming can be easily adapted to a wide range of applications that need exhaustive and continuous environmental monitoring with high spatial resolution. The results show that the WSN design is perfectly suited to the topography and the technical specifications of the sensors, and provides a complete coverage of the environmental variability in terms of Sun exposure. However these results still need be validated in the field and the proposed procedure must be refined. Full article
(This article belongs to the Section Remote Sensors, Control, and Telemetry)
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Open AccessArticle
Sampling-Based Real-Time Motion Planning under State Uncertainty for Autonomous Micro-Aerial Vehicles in GPS-Denied Environments
Sensors 2014, 14(11), 21791-21825; https://doi.org/10.3390/s141121791
Received: 31 July 2014 / Revised: 26 October 2014 / Accepted: 3 November 2014 / Published: 18 November 2014
Cited by 4 | Viewed by 2562 | PDF Full-text (6232 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a real-time motion planning approach for autonomous vehicles with complex dynamics and state uncertainty. The approach is motivated by the motion planning problem for autonomous vehicles navigating in GPS-denied dynamic environments, which involves non-linear and/or non-holonomic vehicle dynamics, incomplete state [...] Read more.
This paper presents a real-time motion planning approach for autonomous vehicles with complex dynamics and state uncertainty. The approach is motivated by the motion planning problem for autonomous vehicles navigating in GPS-denied dynamic environments, which involves non-linear and/or non-holonomic vehicle dynamics, incomplete state estimates, and constraints imposed by uncertain and cluttered environments. To address the above motion planning problem, we propose an extension of the closed-loop rapid belief trees, the closed-loop random belief trees (CL-RBT), which incorporates predictions of the position estimation uncertainty, using a factored form of the covariance provided by the Kalman filter-based estimator. The proposed motion planner operates by incrementally constructing a tree of dynamically feasible trajectories using the closed-loop prediction, while selecting candidate paths with low uncertainty using efficient covariance update and propagation. The algorithm can operate in real-time, continuously providing the controller with feasible paths for execution, enabling the vehicle to account for dynamic and uncertain environments. Simulation results demonstrate that the proposed approach can generate feasible trajectories that reduce the state estimation uncertainty, while handling complex vehicle dynamics and environment constraints. Full article
(This article belongs to the Special Issue Positioning and Tracking Sensors and Technologies in Road Transport)
Open AccessArticle
An Improved Flexible Telemetry System to Autonomously Monitor Sub-Bandage Pressure and Wound Moisture
Sensors 2014, 14(11), 21770-21790; https://doi.org/10.3390/s141121770
Received: 4 September 2014 / Revised: 7 November 2014 / Accepted: 12 November 2014 / Published: 18 November 2014
Cited by 8 | Viewed by 2898 | PDF Full-text (5371 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the development of an improved mobile-based telemetric dual mode sensing system to monitor pressure and moisture levels in compression bandages and dressings used for chronic wound management. The system is fabricated on a 0.2 mm thick flexible printed circuit material, [...] Read more.
This paper presents the development of an improved mobile-based telemetric dual mode sensing system to monitor pressure and moisture levels in compression bandages and dressings used for chronic wound management. The system is fabricated on a 0.2 mm thick flexible printed circuit material, and is capable of sensing pressure and moisture at two locations simultaneously within a compression bandage and wound dressing. The sensors are calibrated to sense both parameters accurately, and the data are then transmitted wirelessly to a receiver connected to a mobile device. An error-correction algorithm is developed to compensate the degradation in measurement quality due to battery power drop over time. An Android application is also implemented to automatically receive, process, and display the sensed wound parameters. The performance of the sensing system is first validated on a mannequin limb using a compression bandage and wound dressings, and then tested on a healthy volunteer to acquire real-time performance parameters. The results obtained here suggest that this dual mode sensor can perform reliably when placed on a human limb. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle
Locally-Referenced Ultrasonic – LPS for Localization and Navigation
Sensors 2014, 14(11), 21750-21769; https://doi.org/10.3390/s141121750
Received: 17 September 2014 / Revised: 15 October 2014 / Accepted: 6 November 2014 / Published: 18 November 2014
Cited by 17 | Viewed by 2217 | PDF Full-text (1792 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a flexible deployment of ultrasonic position sensors and a novel positioning algorithm suitable for the navigation of mobile robots (MRs) in extensive indoor environments. Our proposal uses several independently-referenced local positioning systems (LPS), which means that each one of them [...] Read more.
This paper presents a flexible deployment of ultrasonic position sensors and a novel positioning algorithm suitable for the navigation of mobile robots (MRs) in extensive indoor environments. Our proposal uses several independently-referenced local positioning systems (LPS), which means that each one of them operates within its own local reference system. In a typical layout, an indoor extensive area can be covered using just a reduced set of globally-referenced LPS (GRLPS), whose beacon positions are known to the global reference system, while the rest of the space can be covered using locally-referenced LPSs (LRLPS) that can be distributed arbitrarily. The number of LRLPS and their position can be also changed at any moment. The algorithm is composed of several Bayesian filters running in parallel, so that when an MR is under the GRLPS coverage area, its position is updated by a global filter, whereas when the MR is inside the LRLPS area, its position is updated using position increments within a local filter. The navigation algorithm has been tested by simulation and with actual data obtained using a real set of ultrasonic LPSs. Full article
(This article belongs to the Special Issue Sensors for Indoor Mapping and Navigation)
Open AccessArticle
Face Recognition System for Set-Top Box-Based Intelligent TV
Sensors 2014, 14(11), 21726-21749; https://doi.org/10.3390/s141121726
Received: 18 April 2014 / Revised: 4 November 2014 / Accepted: 11 November 2014 / Published: 18 November 2014
Cited by 16 | Viewed by 3003 | PDF Full-text (4695 KB) | HTML Full-text | XML Full-text
Abstract
Despite the prevalence of smart TVs, many consumers continue to use conventional TVs with supplementary set-top boxes (STBs) because of the high cost of smart TVs. However, because the processing power of a STB is quite low, the smart TV functionalities that can [...] Read more.
Despite the prevalence of smart TVs, many consumers continue to use conventional TVs with supplementary set-top boxes (STBs) because of the high cost of smart TVs. However, because the processing power of a STB is quite low, the smart TV functionalities that can be implemented in a STB are very limited. Because of this, negligible research has been conducted regarding face recognition for conventional TVs with supplementary STBs, even though many such studies have been conducted with smart TVs. In terms of camera sensors, previous face recognition systems have used high-resolution cameras, cameras with high magnification zoom lenses, or camera systems with panning and tilting devices that can be used for face recognition from various positions. However, these cameras and devices cannot be used in intelligent TV environments because of limitations related to size and cost, and only small, low cost web-cameras can be used. The resulting face recognition performance is degraded because of the limited resolution and quality levels of the images. Therefore, we propose a new face recognition system for intelligent TVs in order to overcome the limitations associated with low resource set-top box and low cost web-cameras. We implement the face recognition system using a software algorithm that does not require special devices or cameras. Our research has the following four novelties: first, the candidate regions in a viewer’s face are detected in an image captured by a camera connected to the STB via low processing background subtraction and face color filtering; second, the detected candidate regions of face are transmitted to a server that has high processing power in order to detect face regions accurately; third, in-plane rotations of the face regions are compensated based on similarities between the left and right half sub-regions of the face regions; fourth, various poses of the viewer’s face region are identified using five templates obtained during the initial user registration stage and multi-level local binary pattern matching. Experimental results indicate that the recall; precision; and genuine acceptance rate were about 95.7%; 96.2%; and 90.2%, respectively. Full article
(This article belongs to the Special Issue HCI In Smart Environments)
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Open AccessEditorial
Magnetic Resonance Sensors
Sensors 2014, 14(11), 21722-21725; https://doi.org/10.3390/s141121722
Received: 7 November 2014 / Accepted: 13 November 2014 / Published: 17 November 2014
Cited by 1 | Viewed by 2091 | PDF Full-text (628 KB) | HTML Full-text | XML Full-text
Abstract
Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. [...] Read more.
Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...] Full article
(This article belongs to the Special Issue Magnetic Resonance Sensors) Printed Edition available
Open AccessArticle
Hardware Architecture and Cutting-Edge Assembly Process of a Tiny Curved Compound Eye
Sensors 2014, 14(11), 21702-21721; https://doi.org/10.3390/s141121702
Received: 2 September 2014 / Revised: 7 November 2014 / Accepted: 10 November 2014 / Published: 17 November 2014
Cited by 11 | Viewed by 3475 | PDF Full-text (32259 KB) | HTML Full-text | XML Full-text
Abstract
The demand for bendable sensors increases constantly in the challenging field of soft and micro-scale robotics. We present here, in more detail, the flexible, functional, insect-inspired curved artificial compound eye (CurvACE) that was previously introduced in the Proceedings of the National Academy of [...] Read more.
The demand for bendable sensors increases constantly in the challenging field of soft and micro-scale robotics. We present here, in more detail, the flexible, functional, insect-inspired curved artificial compound eye (CurvACE) that was previously introduced in the Proceedings of the National Academy of Sciences (PNAS, 2013). This cylindrically-bent sensor with a large panoramic field-of-view of \(180^\circ\) \(\times\) \(60^\circ\)composed of 630 artificial ommatidia weighs only 1.75 g, is extremely compact and power-lean (0.9 W), while it achieves unique visual motion sensing performance (1950 frames per second) in a five-decade range of illuminance. In particular, this paper details the innovative Very Large Scale Integration (VLSI) sensing layout, the accurate assembly fabrication process, the innovative, new fast read-out interface, as well as the auto-adaptive dynamic response of the CurvACE sensor. Starting from photodetectors and microoptics on wafer substrates and flexible printed circuit board, the complete assembly of CurvACE was performed in a planar configuration, ensuring high alignment accuracy and compatibility with state-of-the art assembling processes. The characteristics of the photodetector of one artificial ommatidium have been assessed in terms of their dynamic response to light steps. We also characterized the local auto-adaptability of CurvACE photodetectors in response to large illuminance changes: this feature will certainly be of great interest for future applications in real indoor and outdoor environments. Full article
(This article belongs to the Section Physical Sensors)
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Open AccessArticle
Fibre Tip Sensors for Localised Temperature Sensing Based on Rare Earth-Doped Glass Coatings
Sensors 2014, 14(11), 21693-21701; https://doi.org/10.3390/s141121693
Received: 4 September 2014 / Revised: 20 October 2014 / Accepted: 11 November 2014 / Published: 17 November 2014
Cited by 20 | Viewed by 2458 | PDF Full-text (347 KB) | HTML Full-text | XML Full-text
Abstract
We report the development of a point temperature sensor, based on monitoring upconversion emission from erbium:ytterbium-doped tellurite coatings on the tips of optical fibres. The dip coating technique allows multiple sensors to be fabricated simultaneously, while confining the temperature-sensitive region to a localised [...] Read more.
We report the development of a point temperature sensor, based on monitoring upconversion emission from erbium:ytterbium-doped tellurite coatings on the tips of optical fibres. The dip coating technique allows multiple sensors to be fabricated simultaneously, while confining the temperature-sensitive region to a localised region on the end-face of the fibre. The strong response of the rare earth ions to changing temperature allows a resolution of 0.1–0.3 °C to be recorded over the biologically relevant range of temperatures from 23–39 °C. Full article
(This article belongs to the Section Physical Sensors)
Open AccessArticle
Investigation into Alternative Sample Preparation Techniques for the Determination of Heavy Metals in Stationary Source Emission Samples Collected on Quartz Filters
Sensors 2014, 14(11), 21676-21692; https://doi.org/10.3390/s141121676
Received: 26 September 2014 / Revised: 4 November 2014 / Accepted: 5 November 2014 / Published: 17 November 2014
Cited by 5 | Viewed by 2149 | PDF Full-text (757 KB) | HTML Full-text | XML Full-text
Abstract
Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid [...] Read more.
Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid and nitric acid (HF/HNO3) followed by complexing with boric acid (H3BO3) prior to analysis. However, the use of this method presents a number of problems, including significant instrumental drift during analysis caused by the matrix components, often leading to instrument breakdown and downtime for repairs, as well as posing significant health and safety risks. The aim of this work was to develop an alternative sample preparation technique for emissions samples on quartz filters. The alternative techniques considered were: (i) acid digestion in a fluoroboric acid (HBF4) and HNO3 mixture and (ii) acid extraction in an aqua regia (AR) mixture (HCl and HNO3). Assessment of the effectiveness of these options included determination of interferences and signal drift, as well as validating the different methods by measurement of matrix certified reference materials (CRMs), and comparing the results obtained from real test samples and sample blanks to determine limits of detection. The results showed that the HBF4/HNO3 mixture provides the most viable alternative to the documentary standard preparation technique. Full article
(This article belongs to the Special Issue Modern Technologies for Sensing Pollution in Air, Water, and Soil)
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Open AccessArticle
Wireless and Simultaneous Detections of Multiple Bio-Molecules in a Single Sensor Using Love Wave Biosensor
Sensors 2014, 14(11), 21660-21675; https://doi.org/10.3390/s141121660
Received: 27 August 2014 / Revised: 15 October 2014 / Accepted: 24 October 2014 / Published: 17 November 2014
Cited by 10 | Viewed by 2323 | PDF Full-text (1527 KB) | HTML Full-text | XML Full-text
Abstract
A Love wave-based biosensor with a 440 MHz center frequency was developed for the simultaneous detection of two different analytes of Cartilage Oligomeric Matrix Protein (COMP) and rabbit immunoglobulin G (IgG) in a single sensor. The developed biosensor consists of one-port surface acoustic [...] Read more.
A Love wave-based biosensor with a 440 MHz center frequency was developed for the simultaneous detection of two different analytes of Cartilage Oligomeric Matrix Protein (COMP) and rabbit immunoglobulin G (IgG) in a single sensor. The developed biosensor consists of one-port surface acoustic wave (SAW) reflective delay lines on a 41° YX LiNbO3 piezoelectric substrate, a poly(methyl methacrylate) (PMMA) waveguide layer, and two different sensitive films. The Love wave biosensor was wirelessly characterized using two antennas and a network analyzer. The binding of the analytes to the sensitive layers induced a large change in the time positions of the original reflection peaks mainly due to the mass loading effect. The assessed time shifts in the reflection peaks were matched well with the predicted values from coupling of mode (COM) modeling. The sensitivities evaluated from the sensitive films were ~15 deg/µg/mL for the rabbit IgG and ~1.8 deg/ng/mL for COMP. Full article
(This article belongs to the Special Issue Miniaturized Wireless Biosensors)
Open AccessArticle
Multispectral Filter Arrays: Recent Advances and Practical Implementation
Sensors 2014, 14(11), 21626-21659; https://doi.org/10.3390/s141121626
Received: 31 July 2014 / Revised: 24 September 2014 / Accepted: 15 October 2014 / Published: 17 November 2014
Cited by 57 | Viewed by 4309 | PDF Full-text (11735 KB) | HTML Full-text | XML Full-text
Abstract
Thanks to some technical progress in interferencefilter design based on different technologies, we can finally successfully implement the concept of multispectral filter array-based sensors. This article provides the relevant state-of-the-art for multispectral imaging systems and presents the characteristics of the elements of our [...] Read more.
Thanks to some technical progress in interferencefilter design based on different technologies, we can finally successfully implement the concept of multispectral filter array-based sensors. This article provides the relevant state-of-the-art for multispectral imaging systems and presents the characteristics of the elements of our multispectral sensor as a case study. The spectral characteristics are based on two different spatial arrangements that distribute eight different bandpass filters in the visible and near-infrared area of the spectrum. We demonstrate that the system is viable and evaluate its performance through sensor spectral simulation. Full article
(This article belongs to the Special Issue State-of-the-Art Sensors Technology in France)
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