Research

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Open AccessArticle

Engineering a Ca⁺⁺-Sensitive (Bio)Sensor from the Pore-Module of a Potassium Channel

by Mattia Lorenzo DiFrancesco, Sabrina Gazzarrini, Cristina Arrigoni, Giulia Romani, Gerhard Thiel and Anna Moroni

Sensors 2015, 15(3), 4913-4924; https://doi.org/10.3390/s150304913 - 27 Feb 2015

Cited by 3 | Viewed by 6119

Abstract

Signals recorded at the cell membrane are meaningful indicators of the physiological vs. pathological state of a cell and will become useful diagnostic elements in nanomedicine. In this project we present a coherent strategy for the design and fabrication of a bio-nano-sensor that [...] Read more.

Signals recorded at the cell membrane are meaningful indicators of the physiological vs. pathological state of a cell and will become useful diagnostic elements in nanomedicine. In this project we present a coherent strategy for the design and fabrication of a bio-nano-sensor that monitors changes in intracellular cell calcium concentration and allows an easy read out by converting the calcium signal into an electrical current in the range of microampere that can be easily measured by conventional cell electrophysiology apparatus. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Fluorescence Spectroscopy Approaches for the Development of a Real-Time Organophosphate Detection System Using an Enzymatic Sensor

by Paola Carullo, Giovanni Paolo Cetrangolo, Luigi Mandrich, Giuseppe Manco and Ferdinando Febbraio

Sensors 2015, 15(2), 3932-3951; https://doi.org/10.3390/s150203932 - 09 Feb 2015

Cited by 42 | Viewed by 9161

Abstract

Organophosphates are organic substances that contain a phosphoryl or a thiophosphoryl bond. They are mainly used around the world as pesticides, but can also be used as chemical warfare agents. Their detection is normally entrusted to techniques like GC- and LC-MS that, although [...] Read more.

Organophosphates are organic substances that contain a phosphoryl or a thiophosphoryl bond. They are mainly used around the world as pesticides, but can also be used as chemical warfare agents. Their detection is normally entrusted to techniques like GC- and LC-MS that, although sensitive, do not allow their identification on site and in real time. We have approached their identification by exploiting the high-affinity binding of these compounds with the esterase 2 from Alicyclobacillus acidocaldarius. Using an in silico analysis to evaluate the binding affinities of the enzyme with organophosphate inhibitors, like paraoxon, and other organophosphate compounds, like parathion, chlorpyriphos, and other organophosphate thio-derivatives, we have designed fluorescence spectroscopy experiments to study the quenching of the tryptophan residues after esterase 2 binding with the organophosphate pesticides. The changes in the fluorescence signals permitted an immediate and quantitative identification of these compounds from nano- to picomolar concentrations. A fluorescence based polarity-sensitive probe (ANS) was also employed as a means to understand the extent of the interactions involved, as well as to explore other ways to detect organophosphate pesticides. Finally, we designed a framework for the development of a biosensor that exploits fluorescence technology in combination with a sensitive and very stable bio-receptor. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Surveying Multidisciplinary Aspects in Real-Time Distributed Coding for Wireless Sensor Networks

by Carlo Braccini, Franco Davoli, Mario Marchese and Maurizio Mongelli

Sensors 2015, 15(2), 2737-2762; https://doi.org/10.3390/s150202737 - 27 Jan 2015

Cited by 7 | Viewed by 5648

Abstract

Wireless Sensor Networks (WSNs), where a multiplicity of sensors observe a physical phenomenon and transmit their measurements to one or more sinks, pertain to the class of multi-terminal source and channel coding problems of Information Theory. In this category, “real-time” coding is often [...] Read more.

Wireless Sensor Networks (WSNs), where a multiplicity of sensors observe a physical phenomenon and transmit their measurements to one or more sinks, pertain to the class of multi-terminal source and channel coding problems of Information Theory. In this category, “real-time” coding is often encountered for WSNs, referring to the problem of finding the minimum distortion (according to a given measure), under transmission power constraints, attainable by encoding and decoding functions, with stringent limits on delay and complexity. On the other hand, the Decision Theory approach seeks to determine the optimal coding/decoding strategies or some of their structural properties. Since encoder(s) and decoder(s) possess different information, though sharing a common goal, the setting here is that of Team Decision Theory. A more pragmatic vision rooted in Signal Processing consists of fixing the form of the coding strategies (e.g., to linear functions) and, consequently, finding the corresponding optimal decoding strategies and the achievable distortion, generally by applying parametric optimization techniques. All approaches have a long history of past investigations and recent results. The goal of the present paper is to provide the taxonomy of the various formulations, a survey of the vast related literature, examples from the authors’ own research, and some highlights on the inter-play of the different theories. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

A Compact 3D Omnidirectional Range Sensor of High Resolution for Robust Reconstruction of Environments

by Roberto Marani, Vito Renò, Massimiliano Nitti, Tiziana D'Orazio and Ettore Stella

Sensors 2015, 15(2), 2283-2308; https://doi.org/10.3390/s150202283 - 22 Jan 2015

Cited by 12 | Viewed by 6615

Abstract

In this paper, an accurate range sensor for the three-dimensional reconstruction of environments is designed and developed. Following the principles of laser profilometry, the device exploits a set of optical transmitters able to project a laser line on the environment. A high-resolution and [...] Read more.

In this paper, an accurate range sensor for the three-dimensional reconstruction of environments is designed and developed. Following the principles of laser profilometry, the device exploits a set of optical transmitters able to project a laser line on the environment. A high-resolution and high-frame-rate camera assisted by a telecentric lens collects the laser light reflected by a parabolic mirror, whose shape is designed ad hoc to achieve a maximum measurement error of 10 mm when the target is placed 3 m away from the laser source. Measurements are derived by means of an analytical model, whose parameters are estimated during a preliminary calibration phase. Geometrical parameters, analytical modeling and image processing steps are validated through several experiments, which indicate the capability of the proposed device to recover the shape of a target with high accuracy. Experimental measurements show Gaussian statistics, having standard deviation of 1.74 mm within the measurable range. Results prove that the presented range sensor is a good candidate for environmental inspections and measurements. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

An X-Band Radar System for Bathymetry and Wave Field Analysis in a Harbour Area

by Giovanni Ludeno, Ferdinando Reale, Fabio Dentale, Eugenio Pugliese Carratelli, Antonio Natale, Francesco Soldovieri and Francesco Serafino

Sensors 2015, 15(1), 1691-1707; https://doi.org/10.3390/s150101691 - 14 Jan 2015

Cited by 39 | Viewed by 7327

Abstract

Marine X-band radar based systems are well tested to provide information about sea state and bathymetry. It is also well known that complex geometries and non-uniform bathymetries provide a much bigger challenge than offshore scenarios. In order to tackle this issue a retrieval [...] Read more.

Marine X-band radar based systems are well tested to provide information about sea state and bathymetry. It is also well known that complex geometries and non-uniform bathymetries provide a much bigger challenge than offshore scenarios. In order to tackle this issue a retrieval method is proposed, based on spatial partitioning of the data and the application of the Normalized Scalar Product (NSP), which is an innovative procedure for the joint estimation of bathymetry and surface currents. The strategy is then applied to radar data acquired around a harbour entrance, and results show that the reconstructed bathymetry compares well with ground truth data obtained by an echo-sounder campaign, thus proving the reliability of the whole procedure. The spectrum thus retrieved is then analysed to show the evidence of reflected waves from the harbour jetties, as confirmed by chain of hydrodynamic models of the sea wave field. The possibility of using a land based radar to reveal sea wave reflection is entirely new and may open up new operational applications of the system. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Development and Experimental Validation of a Numerical Tool for Structural Health and Usage Monitoring Systems Based on Chirped Grating Sensors

by Paolo Bettini, Erika Guerreschi and Giuseppe Sala

Sensors 2015, 15(1), 1321-1341; https://doi.org/10.3390/s150101321 - 12 Jan 2015

Cited by 32 | Viewed by 6045

Abstract

The interest of the aerospace industries in structural health and usage monitoring systems is continuously increasing. Among the techniques available in literature those based on Fibre Bragg Grating sensors are much promising thanks to their peculiarities. Different Chirped Bragg Grating sensor configurations have [...] Read more.

The interest of the aerospace industries in structural health and usage monitoring systems is continuously increasing. Among the techniques available in literature those based on Fibre Bragg Grating sensors are much promising thanks to their peculiarities. Different Chirped Bragg Grating sensor configurations have been investigated in this paper. Starting from a numerical model capable of simulating the spectral response of a grating subjected to a generic strain profile (direct problem), a new code has been developed, allowing strain reconstruction from the experimental validation of the program, carried out through different loading cases applied on a chirped grating. The wavelength of the reflection spectrum for a chirped FBG has a one-to-one correspondence to the position along the gauge section, thus allowing strain reconstruction over the entire sensor length. Tests conducted on chirped FBGs also evidenced their potential for SHM applications, if coupled with appropriate numerical strain reconstructions tools. Finally, a new class of sensors—Draw Tower Grating arrays—has been studied. These sensors are applicable to distributed sensing and load reconstruction over large structures, thanks to their greater length. Three configurations have been evaluated, having different spatial and spectral characteristics, in order to explore possible applications of such sensors to SHM systems. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

WhiteRef: A New Tower-Based Hyperspectral System for Continuous Reflectance Measurements

by Karolina Sakowska, Damiano Gianelle, Alessandro Zaldei, Alasdair MacArthur, Federico Carotenuto, Franco Miglietta, Roberto Zampedri, Mauro Cavagna and Loris Vescovo

Sensors 2015, 15(1), 1088-1105; https://doi.org/10.3390/s150101088 - 08 Jan 2015

Cited by 18 | Viewed by 9133

Abstract

Proximal sensing is fundamental to monitor the spatial and seasonal dynamics of ecosystems and can be considered as a crucial validation tool to upscale in situ observations to the satellite level. Linking hyperspectral remote sensing with carbon fluxes and biophysical parameters is critical [...] Read more.

Proximal sensing is fundamental to monitor the spatial and seasonal dynamics of ecosystems and can be considered as a crucial validation tool to upscale in situ observations to the satellite level. Linking hyperspectral remote sensing with carbon fluxes and biophysical parameters is critical to allow the exploitation of spatial and temporal extensive information for validating model simulations at different scales. In this study, we present the WhiteRef, a new hyperspectral system designed as a direct result of the needs identified during the EUROSPEC ES0903 Cost Action, and developed by Fondazione Edmund Mach and the Institute of Biometeorology, CNR, Italy. The system is based on the ASD FieldSpec Pro spectroradiometer and was designed to acquire continuous radiometric measurements at the Eddy Covariance (EC) towers and to fill a gap in the scientific community: in fact, no system for continuous spectral measurements in the Short Wave Infrared was tested before at the EC sites. The paper illustrates the functioning of the WhiteRef and describes its main advantages and disadvantages. The WhiteRef system, being based on a robust and high quality commercially available instrument, has a clear potential for unattended continuous measurements aiming at the validation of satellites’ vegetation products. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Non-Invasive UWB Sensing of Astronauts’ Breathing Activity

by Marco Baldi, Graziano Cerri, Franco Chiaraluce, Lorenzo Eusebi and Paola Russo

Sensors 2015, 15(1), 565-591; https://doi.org/10.3390/s150100565 - 30 Dec 2014

Cited by 28 | Viewed by 7453

Abstract

The use of a UWB system for sensing breathing activity of astronauts must account for many critical issues specific to the space environment. The aim of this paper is twofold. The first concerns the definition of design constraints about the pulse amplitude and [...] Read more.

The use of a UWB system for sensing breathing activity of astronauts must account for many critical issues specific to the space environment. The aim of this paper is twofold. The first concerns the definition of design constraints about the pulse amplitude and waveform to transmit, as well as the immunity requirements of the receiver. The second issue concerns the assessment of the procedures and the characteristics of the algorithms to use for signal processing to retrieve the breathing frequency and respiration waveform. The algorithm has to work correctly in the presence of surrounding electromagnetic noise due to other sources in the environment. The highly reflecting walls increase the difficulty of the problem and the hostile scenario has to be accurately characterized. Examples of signal processing techniques able to recover breathing frequency in significant and realistic situations are shown and discussed. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Development and Characterization of a Diamond-Insulated Graphitic Multi Electrode Array Realized with Ion Beam Lithography

by Federico Picollo, Alfio Battiato, Emilio Carbone, Luca Croin, Emanuele Enrico, Jacopo Forneris, Sara Gosso, Paolo Olivero, Alberto Pasquarelli and Valentina Carabelli

Sensors 2015, 15(1), 515-528; https://doi.org/10.3390/s150100515 - 30 Dec 2014

Cited by 25 | Viewed by 6289

Abstract

The detection of quantal exocytic events from neurons and neuroendocrine cells is a challenging task in neuroscience. One of the most promising platforms for the development of a new generation of biosensors is diamond, due to its biocompatibility, transparency and chemical inertness. Moreover, [...] Read more.

The detection of quantal exocytic events from neurons and neuroendocrine cells is a challenging task in neuroscience. One of the most promising platforms for the development of a new generation of biosensors is diamond, due to its biocompatibility, transparency and chemical inertness. Moreover, the electrical properties of diamond can be turned from a perfect insulator into a conductive material (resistivity ~mΩ·cm) by exploiting the metastable nature of this allotropic form of carbon. A 16‑channels MEA (Multi Electrode Array) suitable for cell culture growing has been fabricated by means of ion implantation. A focused 1.2 MeV He⁺ beam was scanned on a IIa single-crystal diamond sample (4.5 × 4.5 × 0.5 mm³) to cause highly damaged sub-superficial structures that were defined with micrometric spatial resolution. After implantation, the sample was annealed. This process provides the conversion of the sub-superficial highly damaged regions to a graphitic phase embedded in a highly insulating diamond matrix. Thanks to a three-dimensional masking technique, the endpoints of the sub-superficial channels emerge in contact with the sample surface, therefore being available as sensing electrodes. Cyclic voltammetry and amperometry measurements of solutions with increasing concentrations of adrenaline were performed to characterize the biosensor sensitivity. The reported results demonstrate that this new type of biosensor is suitable for in vitro detection of catecholamine release. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Evaluation of Multi-Resolution Satellite Sensors for Assessing Water Quality and Bottom Depth of Lake Garda

by Claudia Giardino, Mariano Bresciani, Ilaria Cazzaniga, Karin Schenk, Patrizia Rieger, Federica Braga, Erica Matta and Vittorio E. Brando

Sensors 2014, 14(12), 24116-24131; https://doi.org/10.3390/s141224116 - 15 Dec 2014

Cited by 94 | Viewed by 9806

Abstract

In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat-8 Operational Land Imager (OLI) and RapidEye. Images [...] Read more.

In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat-8 Operational Land Imager (OLI) and RapidEye. Images gathered on 10 June 2014 were corrected for the atmospheric effects with the 6SV code. The computed remote sensing reflectance (R_rs) from MODIS and OLI were converted into water quality parameters by adopting a spectral inversion procedure based on a bio-optical model calibrated with optical properties of the lake. The same spectral inversion procedure was applied to RapidEye and to OLI data to map bottom depth. In situ measurements of R_rs and of concentrations of water quality parameters collected in five locations were used to evaluate the models. The bottom depth maps from OLI and RapidEye showed similar gradients up to 7 m (r = 0.72). The results indicate that: (1) the spatial and radiometric resolutions of OLI enabled mapping water constituents and bottom properties; (2) MODIS was appropriate for assessing water quality in the pelagic areas at a coarser spatial resolution; and (3) RapidEye had the capability to retrieve bottom depth at high spatial resolution. Future work should evaluate the performance of the three sensors in different bio-optical conditions. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Design Concepts, Fabrication and Advanced Characterization Methods of Innovative Piezoelectric Sensors Based on ZnO Nanowires

by Rodolfo Araneo, Antonio Rinaldi, Andrea Notargiacomo, Fabiano Bini, Marialilia Pea, Salvatore Celozzi, Franco Marinozzi and Giampiero Lovat

Sensors 2014, 14(12), 23539-23562; https://doi.org/10.3390/s141223539 - 08 Dec 2014

Cited by 26 | Viewed by 7271

Abstract

Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct [...] Read more.

Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct bandgap, piezoelectricity, pyroelectricity and biocompatibility. Most applications are based on the cooperative and average response of a large number of ZnO micro/nanostructures. However, in order to assess the quality of the materials and their performance, it is fundamental to characterize and then accurately model the specific electrical and piezoelectric properties of single ZnO structures. In this paper, we report on focused ion beam machined high aspect ratio nanowires and their mechanical and electrical (by means of conductive atomic force microscopy) characterization. Then, we investigate the suitability of new power-law design concepts to accurately model the relevant electrical and mechanical size-effects, whose existence has been emphasized in recent reviews. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Design and Application of New Low-Cost Instruments for Marine Environmental Research

by Marco Marcelli, Viviana Piermattei, Alice Madonia and Umberto Mainardi

Sensors 2014, 14(12), 23348-23364; https://doi.org/10.3390/s141223348 - 05 Dec 2014

Cited by 33 | Viewed by 6742

Abstract

The development of low-cost instrumentation plays a key role in marine environmental studies and represents one of the most innovative aspects of current oceanographic research. These kinds of devices can be used for several applications, ranging from vertical profilers to stand-alone systems, and [...] Read more.

The development of low-cost instrumentation plays a key role in marine environmental studies and represents one of the most innovative aspects of current oceanographic research. These kinds of devices can be used for several applications, ranging from vertical profilers to stand-alone systems, and can be installed on different platforms (buoys, Voluntary Observing Ships, underwater vehicles, etc.). The availability of low-cost technologies enables the realization of extended observatory networks for the study of marine physical and biological processes through an integrated approach merging in situ observations, forecasting models and remotely sensed data. We present new low-cost sensors and probes developed to measure marine temperature, conductivity, chlorophyll a and Chromophoric Dissolved Organic Matter fluorescence, focusing on sensing strategies, general architecture, laboratory trials, in situ tests and comparison with standard instruments. Furthermore, we report the expendable (New T-FLaP), vertical profiler (T-FLaPpro) and stand-alone (Spectra) applications of these technological developments that were tested during several oceanographic surveys in the Mediterranean Sea. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

A Sensorized Nuss Bar for Patient-Specific Treatment of Pectus Excavatum

by Stefano Betti, Gastone Ciuti, Leonardo Ricotti, Marco Ghionzoli, Filippo Cavallo, Antonio Messineo and Arianna Menciassi

Sensors 2014, 14(10), 18096-18113; https://doi.org/10.3390/s141018096 - 29 Sep 2014

Cited by 6 | Viewed by 8538

Abstract

Pectus Excavatum is an anatomical deformation characterized by a depression of the anterior chest wall. Nuss technique (representing the current clinical golden standard) consists in the introduction of a corrective metal bar, in order to raise the sternum in its anatomic natural position. [...] Read more.

Pectus Excavatum is an anatomical deformation characterized by a depression of the anterior chest wall. Nuss technique (representing the current clinical golden standard) consists in the introduction of a corrective metal bar, in order to raise the sternum in its anatomic natural position. Nowadays, the bar plays purely a mechanical/corrective action and is kept implanted for about three years, supporting up to a maximum force of 250 N. Our study aims at optimizing the procedure of correction, in terms of monitoring the bar effect, minimizing the body response, and facilitating the bar removal. The sensorized Nuss bar prototype inserted in a platform for telemedicine described in this article is able to monitor in vitro pressure data variations, with more than 150 discrete measurements during the operating period. This behavior is promising for future clinical applications, in which the device could be exploited to monitor the forces at work, thus, providing a customized therapeutic protocol, which in turn may optimize the period of implant. The sensorized bar was also provided with a polymeric coating, able to influence human dermal fibroblast behavior in vitro. This highlights the possibility to minimize, in future in vivo applications, tissue fibrotic responses. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Calibration of Action Cameras for Photogrammetric Purposes

by Caterina Balletti, Francesco Guerra, Vassilios Tsioukas and Paolo Vernier

Sensors 2014, 14(9), 17471-17490; https://doi.org/10.3390/s140917471 - 18 Sep 2014

Cited by 86 | Viewed by 14758

Abstract

The use of action cameras for photogrammetry purposes is not widespread due to the fact that until recently the images provided by the sensors, using either still or video capture mode, were not big enough to perform and provide the appropriate analysis with [...] Read more.

The use of action cameras for photogrammetry purposes is not widespread due to the fact that until recently the images provided by the sensors, using either still or video capture mode, were not big enough to perform and provide the appropriate analysis with the necessary photogrammetric accuracy. However, several manufacturers have recently produced and released new lightweight devices which are: (a) easy to handle, (b) capable of performing under extreme conditions and more importantly (c) able to provide both still images and video sequences of high resolution. In order to be able to use the sensor of action cameras we must apply a careful and reliable self-calibration prior to the use of any photogrammetric procedure, a relatively difficult scenario because of the short focal length of the camera and its wide angle lens that is used to obtain the maximum possible resolution of images. Special software, using functions of the OpenCV library, has been created to perform both the calibration and the production of undistorted scenes for each one of the still and video image capturing mode of a novel action camera, the GoPro Hero 3 camera that can provide still images up to 12 Mp and video up 8 Mp resolution. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Performance of SOI Bragg Grating Ring Resonator for Nonlinear Sensing Applications

by Francesco De Leonardis, Carlo Edoardo Campanella, Benedetto Troia, Anna Gina Perri and Vittorio M. N. Passaro

Sensors 2014, 14(9), 16017-16034; https://doi.org/10.3390/s140916017 - 28 Aug 2014

Cited by 28 | Viewed by 8771

Abstract

In this paper, a spectroscopic sensor formed by a silicon-on-insulator waveguiding Bragg grating ring resonator working in linear and non-linear regime is proposed. In linear regime, the device shows a spectral response characterized by a photonic band gap (PBG). Very close to the [...] Read more.

In this paper, a spectroscopic sensor formed by a silicon-on-insulator waveguiding Bragg grating ring resonator working in linear and non-linear regime is proposed. In linear regime, the device shows a spectral response characterized by a photonic band gap (PBG). Very close to the band gap edges, the resonant structure exhibits split modes having a splitting magnitude equal to the PBG spectral extension, whose characteristics can be exploited to obtain a RI optical sensor almost insensitive to the fabrication tolerances and environmental perturbations. When the device operates in nonlinear regime, exactly in the spectral region showing the split resonant modes, the RI sensing performance is strongly improved with respect to the linear regime. This improvement, demonstrated by taking into account all the non-linear effects excited in the integrated silicon structure (i.e., Two Photon Absorption (TPA), TPA-induced Free Carrier Absorption, plasma dispersion, Self-Phase-Modulation and Cross-Phase-Modulation effects as induced by Kerr nonlinearity) as well as the deleterious thermal and stress effects, allows enhancing the performance of the RI split mode resonant sensors, while achieving good immunity to the fabrication tolerances and environmental perturbations. The improvement in terms of sensor resolution can be at least one order of magnitude, still without using optimal parameters. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Graphical abstract

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Open AccessArticle

Mapping Asbestos-Cement Roofing with Hyperspectral Remote Sensing over a Large Mountain Region of the Italian Western Alps

by Federico Frassy, Gabriele Candiani, Marco Rusmini, Pieralberto Maianti, Andrea Marchesi, Francesco Rota Nodari, Giorgio Dalla Via, Carlo Albonico and Marco Gianinetto

Sensors 2014, 14(9), 15900-15913; https://doi.org/10.3390/s140915900 - 27 Aug 2014

Cited by 38 | Viewed by 7758

Abstract

The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned [...] Read more.

The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km² were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d’Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification’s accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessArticle

Multichannel System Based on a High Sensitivity Superconductive Sensor for Magnetoencephalography

by Sara Rombetto, Carmine Granata, Antonio Vettoliere and Maurizio Russo

Sensors 2014, 14(7), 12114-12126; https://doi.org/10.3390/s140712114 - 08 Jul 2014

Cited by 23 | Viewed by 7441

Abstract

We developed a multichannel system based on superconducting quantum interference devices (SQUIDs) for magnetoencephalography measurements. Our system consists of 163 fully-integrated SQUID magnetometers, 154 channels and 9 references, and all of the operations are performed inside a magnetically-shielded room. The system exhibits a [...] Read more.

We developed a multichannel system based on superconducting quantum interference devices (SQUIDs) for magnetoencephalography measurements. Our system consists of 163 fully-integrated SQUID magnetometers, 154 channels and 9 references, and all of the operations are performed inside a magnetically-shielded room. The system exhibits a magnetic field noise spectral density of approximatively 5 fT/Hz1=2. The presented magnetoencephalography is the first system working in a clinical environment in Italy. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Review

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Open AccessReview

MEMS Sensor Technologies for Human Centred Applications in Healthcare, Physical Activities, Safety and Environmental Sensing: A Review on Research Activities in Italy

by Gastone Ciuti, Leonardo Ricotti, Arianna Menciassi and Paolo Dario

Sensors 2015, 15(3), 6441-6468; https://doi.org/10.3390/s150306441 - 17 Mar 2015

Cited by 124 | Viewed by 19495

Abstract

Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to sense, classify, and provide feedbacks to users’ health status and [...] Read more.

Over the past few decades the increased level of public awareness concerning healthcare, physical activities, safety and environmental sensing has created an emerging need for smart sensor technologies and monitoring devices able to sense, classify, and provide feedbacks to users’ health status and physical activities, as well as to evaluate environmental and safety conditions in a pervasive, accurate and reliable fashion. Monitoring and precisely quantifying users’ physical activity with inertial measurement unit-based devices, for instance, has also proven to be important in health management of patients affected by chronic diseases, e.g., Parkinson’s disease, many of which are becoming highly prevalent in Italy and in the Western world. This review paper will focus on MEMS sensor technologies developed in Italy in the last three years describing research achievements for healthcare and physical activity, safety and environmental sensing, in addition to smart systems integration. Innovative and smart integrated solutions for sensing devices, pursued and implemented in Italian research centres, will be highlighted, together with specific applications of such technologies. Finally, the paper will depict the future perspective of sensor technologies and corresponding exploitation opportunities, again with a specific focus on Italy. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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Open AccessReview

Optofluidic Approaches for Enhanced Microsensor Performances

by Genni Testa, Gianluca Persichetti and Romeo Bernini

Sensors 2015, 15(1), 465-484; https://doi.org/10.3390/s150100465 - 30 Dec 2014

Cited by 30 | Viewed by 7163

Abstract

Optofluidics is a relatively young research field able to create a tight synergy between optics and micro/nano-fluidics. The high level of integration between fluidic and optical elements achievable by means of optofluidic approaches makes it possible to realize an innovative class of sensors, [...] Read more.

Optofluidics is a relatively young research field able to create a tight synergy between optics and micro/nano-fluidics. The high level of integration between fluidic and optical elements achievable by means of optofluidic approaches makes it possible to realize an innovative class of sensors, which have been demonstrated to have an improved sensitivity, adaptability and compactness. Many developments in this field have been made in the last years thanks to the availability of a new class of low cost materials and new technologies. This review describes the Italian state of art on optofluidic devices for sensing applications and offers a perspective for further future advances. We introduce the optofluidic concept and describe the advantages of merging photonic and fluidic elements, focusing on sensor developments for both environmental and biomedical monitoring. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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3467 KiB

Open AccessReview

Heat Flux Sensors for Infrared Thermography in Convective Heat Transfer

by Giovanni Maria Carlomagno, Luigi De Luca, Gennaro Cardone and Tommaso Astarita

Sensors 2014, 14(11), 21065-21116; https://doi.org/10.3390/s141121065 - 07 Nov 2014

Cited by 14 | Viewed by 9230

Abstract

This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors’ research group at the University of Naples Federico II. After [...] Read more.

This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors’ research group at the University of Naples Federico II. After recalling the basic principles that make IR thermography work, the various heat flux sensors to be used with it are presented and discussed, describing their capability to investigate complex thermo-fluid-dynamic flows. Several applications to streams, which range from natural convection to hypersonic flows, are also described. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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960 KiB

Open AccessReview

Electronic Noses for Environmental Monitoring Applications

by Laura Capelli, Selena Sironi and Renato Del Rosso

Sensors 2014, 14(11), 19979-20007; https://doi.org/10.3390/s141119979 - 24 Oct 2014

Cited by 193 | Viewed by 10771

Abstract

Electronic nose applications in environmental monitoring are nowadays of great interest, because of the instruments’ proven capability of recognizing and discriminating between a variety of different gases and odors using just a small number of sensors. Such applications in the environmental field include [...] Read more.

Electronic nose applications in environmental monitoring are nowadays of great interest, because of the instruments’ proven capability of recognizing and discriminating between a variety of different gases and odors using just a small number of sensors. Such applications in the environmental field include analysis of parameters relating to environmental quality, process control, and verification of efficiency of odor control systems. This article reviews the findings of recent scientific studies in this field, with particular focus on the abovementioned applications. In general, these studies prove that electronic noses are mostly suitable for the different applications reported, especially if the instruments are specifically developed and fine-tuned. As a general rule, literature studies also discuss the critical aspects connected with the different possible uses, as well as research regarding the development of effective solutions. However, currently the main limit to the diffusion of electronic noses as environmental monitoring tools is their complexity and the lack of specific regulation for their standardization, as their use entails a large number of degrees of freedom, regarding for instance the training and the data processing procedures. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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4216 KiB

Open AccessLetter

Palladium on Plastic Substrates for Plasmonic Devices

by Paola Zuppella, Elisabetta Pasqualotto, Sara Zuccon, Francesca Gerlin, Alain Jody Corso, Matteo Scaramuzza, Alessandro De Toni, Alessandro Paccagnella and Maria Guglielmina Pelizzo

Sensors 2015, 15(1), 1138-1147; https://doi.org/10.3390/s150101138 - 09 Jan 2015

Cited by 15 | Viewed by 5636

Abstract

Innovative chips based on palladium thin films deposited on plastic substrates have been tested in the Kretschmann surface plasmon resonance (SPR) configuration. The new chips combine the advantages of a plastic support that is interesting and commercially appealing and the physical properties of [...] Read more.

Innovative chips based on palladium thin films deposited on plastic substrates have been tested in the Kretschmann surface plasmon resonance (SPR) configuration. The new chips combine the advantages of a plastic support that is interesting and commercially appealing and the physical properties of palladium, showing inverted surface plasmon resonance (ISPR). The detection of DNA chains has been selected as the target of the experiment, since it can be applied to several medical early diagnostic tools, such as different biomarkers of cancers or cystic fibrosis. The results are encouraging for the use of palladium in SPR-based sensors of interest for both the advancement of biodevices and the development of hydrogen sensors. Full article

(This article belongs to the Special Issue State-of-the-Art Sensors Technology in Italy 2014)

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