Publications

2020

• The challenge of controlling microgrids in the presence of rare events with Deep Reinforcement Learning
  
  • Levent Tanguy
  • Preux Philippe
  • Henri Gonzague
  • Alami Réda
  • Cordier Philippe
  • Bonnassieux Yvan
  IET Smart Grid, Institution of Engineering and Technology, 2020. (10.1049/stg2.12003)
  DOI : 10.1049/stg2.12003
• Polypyrrole nanostructures modified with mono- and bimetallic nanoparticles for photocatalytic H2 generation
  
  • Yuan Xiaojiao
  • Dragoe Diana
  • Beaunier Patricia
  • Uribe Daniel Bahena
  • Ramos Laurence
  • Méndez-Medrano Maria Guadalupe
  • Remita Hynd
  Journal of Materials Chemistry A, Royal Society of Chemistry, 2020, 8 (1), pp.268-277. Conjugated polymer polypyrrole nanostructures modified with bimetallic (Pt–Ni) nanoparticles are very active for hydrogen generation and a synergetic effect is obtained by alloying Pt with Ni. (10.1039/C9TA11088G)
  DOI : 10.1039/C9TA11088G
• Low-Temperature Plasma-Assisted Growth of Core–Shell GeSn Nanowires with 30% Sn
  
  • Azrak Edy
  • Chen Wanghua
  • Moldovan Simona
  • Duguay Sébastien
  • Pareige Philippe
  • Roca I Cabarrocas Pere
  Journal of Physical Chemistry C, American Chemical Society, 2020, 124 (1), pp.1220-1226. (10.1021/acs.jpcc.9b10444)
  DOI : 10.1021/acs.jpcc.9b10444
• Nonideal optical response of liquid crystal variable retarders and its impact on their performance as polarization modulators
  
  • García Parejo Pilar
  • Campos-Jara Antonio
  • García-Caurel Enric
  • Arteaga Oriol
  • Álvarez-Herrero Alberto
  Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics, AVS through the American Institute of Physics, 2020, 38 (1), pp.476-479. Liquid crystal variable retarders (LCVRs) will be used for the first time in a space instrument, the Solar Orbiter mission of the European Space Agency, as polarization states analyzers (PSAs). These devices will determine the Stokes parameters of the light coming from the Sun by temporal polarization modulation, using the so-called modulation matrix O. This is a matrix constituted by the first rows of properly selected PSA Mueller matrices. Calibrating a space instrument, in particular, finding O, is a critical point because in a spacecraft there is no possibility of physical access. Due to the huge difficulty in calibrating the complete instruments in all possible scenarios, a more complete calibration of the individual components has been done in ground in order to make extrapolations to obtain O in-flight. Nevertheless, apart from the individual calibrations, the experimental errors and nonideal effects that inhibit the system to reach the designed and theoretical values must be known. In this work, description and study of these effects have been done, focusing on the nonideal effects of the LCVRs and the azimuthal misalignments between the optical components of the PSA during the mechanical assembly. The Mueller matrix of a representative LCVR has been measured and mathematically decomposed by logarithm decomposition, looking for values of circular birefringence and fast axis angle variations as a function of voltage. These effects, in the absence of other nonidealities, affect the polarimetric performance, reducing the polarimetric efficiencies in some cases until 11%. Nevertheless, in this case, they are negligible if compared to the other nonideality studied, which are the azimuthal misalignments between the PSA optical components. The study presented in this work is key to extrapolate the PSA O matrix if the expected instrumental set-point temperatures are not reached in flight and can be used for the design and implementation of other polarimetric instruments. (10.1116/1.5122749)
  DOI : 10.1116/1.5122749
• Analysis of tissue microstructure with Mueller microscopy: logarithmic decomposition and Monte Carlo modeling
  
  • Li Pengcheng
  • Lee Hee Ryung
  • Chandel Shubham
  • Lotz Christian
  • Groeber-Becker Florian Kai
  • Dembski Sofia
  • Ossikovski Razvigor
  • Ma Hui
  • Novikova Tatiana
  Journal of Biomedical Optics, Society of Photo-optical Instrumentation Engineers, 2020, 25 (01), pp.1. (10.1117/1.JBO.25.1.015002)
  DOI : 10.1117/1.JBO.25.1.015002
• Impact of PECVD μc-Si:H deposition on tunnel oxide for passivating contacts
  
  • Desthieux Anatole
  • Posada Jorge
  • Grand Pierre-Philippe
  • Broussillou Cédric
  • Bazer-Bachi Barbara
  • Goaer Gilles
  • Messou Davina
  • Bouttemy Muriel
  • Drahi Etienne
  • Roca I Cabarrocas Pere
  EPJ Photovoltaics, EDP sciences, 2020, 11. Passivating contacts are becoming a mainstream option in current photovoltaic industry due to their ability to provide an outstanding surface passivation along with a good conductivity for carrier collection. However, their integration usually requires long annealing steps which are not desirable in industry. In this work we study PECVD as a way to carry out all deposition steps: silicon oxide (SiO x), doped polycrystalline silicon (poly-Si) and silicon nitride (SiN x :H), followed by a single firing step. Blistering of the poly-Si layer has been avoided by depositing (p +) microcrystalline silicon (mc-Si:H). We report on the impact of this deposition step on the SiO x layer deposited by PECVD, and on the passivation properties by comparing PECVD and wet-chemical oxide in this hole-selective passivating contact stack. We have reached iVoc > 690 mV on p-type FZ wafers for wet-chemical SiO x \(p +) mc-Si\SiN x :H with no annealing step. (10.1051/epjpv/2020001)
  DOI : 10.1051/epjpv/2020001
• Evolution of raw meat polarization‐based properties by means of Mueller matrix imaging
  
  • Peyvasteh Motahareh
  • Popov Alexey
  • Bykov Alexander
  • Pierangelo Angelo
  • Novikova Tatiana
  • Meglinski Igor
  Journal of Biophotonics, Wiley, 2020. (10.1002/jbio.202000376)
  DOI : 10.1002/jbio.202000376
• Electron irradiation induced aging effects on radiative recombination properties of quadruple cation organic-inorganic perovskite layers
  
  • Aversa Pierfrancesco
  • Öz Senol
  • Jung Eunhwan
  • Plantevin Olivier
  • Cavani Olivier
  • Ollier Nadège
  • Bourée Jean-Eric
  • Geffroy Bernard
  • Miyasaka Tsutomu
  • Mathur Sanjay
  • Corbel Catherine
  Emergent Materials, Springer, 2020, 3, pp.133-160. Understanding the role of defects in hybrid organic inorganic perovskites (HOIPs) is critically important to engineer the stability and performance of photovoltaic devices based on HOIPs. Recent reports on multi-cation compositions of general formula (A$^1$,A$^2$,A$^3$,A$^4$)Pb(X$^1$,X$^2$,X$^3$)$_3$, where the A sites can be occupied by a distribution of 2–4 metallic/organic cations and X sites with halide anions have shown stabilization effects against the well-known methyl ammonium lead triiodide (CH$_3$NH$_3$PbI$_3$), although the underlying mechanism is not fully elucidated. Herein, polycrystalline layers of 4APb(IBr)$_3$ perovskite, where A is occupied by a combination of Cs$^+$ (cesium ion), GA$^+$ (guanidinium), MA$^+$ (methylammonium), and FA$^+$(formamidinium) ions were synthesized. To gain insight on the role of intrinsic defects, electron irradiation was used for introducing point defects in a controlled way in the quadruple-cation HOIPs. Our results show that the engineered defects in perovskites strongly influenced the absorption, photoluminescence, and time-resolved photoluminescence of these materials, probably due to introduction of additional energy levels that modify electronic and light emitting properties of the material. Furthermore, the irradiation-induced defects were found to strongly affect the aging behavior of HOIPs and modify their radiative recombination properties. (10.1007/s42247-020-00096-z)
  DOI : 10.1007/s42247-020-00096-z
• Evaluating β-amyloidosis progression in Alzheimer’s disease with Mueller polarimetry
  
  • Borovkova Mariia
  • Bykov Alexander
  • Popov Alexey
  • Pierangelo Angelo
  • Novikova Tatiana
  • Pahnke Jens
  • Meglinski Igor
  Biomedical optics express, Optical Society of America - OSA Publishing, 2020, 11 (8), pp.4509. We applied the wide-field Mueller imaging polarimetry for the screening of formalin-fixed paraffin-embedded samples of mouse brain tissue at different stages of brain β-amyloidosis in Alzheimer’s disease (AD). The accumulation of amyloid-beta (Aβ) deposits throughout the brain tissue is one of the key pathological hallmarks observed with the AD progression. We demonstrate that the presence of Aβ plaques influences the properties of backscattered polarized light, in particular, its degree of depolarization. By means of statistical analysis, we demonstrate that the high-order statistical moments of depolarization distributions, acquired with the multi-spectral Mueller imaging polarimetry, can be used as sensitive markers of the growing presence of Aβ plaques. The introduced label-free polarimetric approach has a potential to facilitate the current practice of the histopathology screening in terms of diagnosis accuracy, time and cost efficiency. (10.1364/BOE.396294)
  DOI : 10.1364/BOE.396294
• Protective coatings for front surface silver mirrors by atomic layer deposition
  
  • Bulkin Pavel
  • Gaiaschi Sofia
  • Chapon Patrick
  • Daineka Dmitri
  • Kundikova Natalya
  Optics Express, Optical Society of America - OSA Publishing, 2020, 28 (11), pp.15753-15760. The problem of protection of the front surface silver mirrors is a very important one for a number of applications. The atomic layer deposition (ALD) technique provides an efficient way to form a coating, protecting the sensitive surface of silver from a corrosive and oxidizing environment. Moreover, the ALD layer provides extremely high conformality (even when deposited over high aspect ratio features) and has high integrity, efficiently blocking foreign species diffusion to the silver-overcoat interface. We tested the efficiency of the protection of silver mirrors against oxygen plasma exposure by the ALD-deposited Al 2 O 3 layers by combining spectroscopic ellipsometry, reflection measurements and pulsed glow-discharge optical emission spectroscopy (GD-OES) profiling. We have found that for optimal protection, the thickness of the ALD deposited layer should exceed at least 15 nm (about 150 ALD cycles at 150°C). We have also demonstrated that the deposition of 15 nm of a protective ALD-deposited Al 2 O 3 layer does not affect the absolute reflectivity of a silver mirror in the spectral range 320 -2500 nm. (10.1364/OE.388546)
  DOI : 10.1364/OE.388546
• In-situ monitoring of an organic sample with electric field determination during cold plasma jet exposure
  
  • Slikboer Elmar
  • Sobota Ana
  • Garcia-Caurel Enric
  • Guaitella Olivier
  Scientific Reports, Nature Publishing Group, 2020, 10, pp.13580. Pockels-based Mueller polarimetry is presented as a novel diagnostic technique for studying time and space-resolved and in-situ the interaction between an organic sample (a layer of onion cells) and non-thermal atmospheric pressure plasma. The effect of plasma is complex, as it delivers electric field, radicals, (UV) radiation, non-uniform in time nor in space. This work shows for the first time that the plasma-surface interaction can be characterized through the induced electric field in an electro-optic crystal (birefringence caused by the Pockels effect) while at the same moment the surface evolution of the targeted sample is monitored (depolarization) which is attached to the crystal. As Mueller polarimetry allows for separate detection of depolarization and birefringence, it is possible to decouple the entangled effects of the plasma. In the sample three spatial regions are identified where the surface evolution of the sample differs. This directly relates to the spatial in-homogeneity of the plasma at the surface characterized through the detected electric field. The method can be applied in the future to investigate plasma-surface interactions for various targets ranging from bio-films, to catalytic surfaces and plastics/polymers. (10.1038/s41598-020-70452-w)
  DOI : 10.1038/s41598-020-70452-w
• Spirophenylacridine‐2,7‐(diphenylphosphineoxide)‐fluorene: A Bipolar Host for High‐Efficiency Single‐Layer Blue Phosphorescent Organic Light‐Emitting Diodes
  
  • Lucas Fabien
  • Ibraikulov Olzhas
  • Quinton Cassandre
  • Sicard Lambert
  • Heiser Thomas
  • Tondelier Denis
  • Geffroy Bernard
  • Leclerc Nicolas
  • Rault‐berthelot Joëlle
  • Poriel Cyril
  Advanced Optical Materials, Wiley, 2020, 8 (2), pp.1901225. Herein, a high-efficiency host material for single-layer phosphorescent organic light-emitting diodes (SL-PhOLEDs) is reported. This host material is synthesized via an efficient approach and is constructed on the association of an electron-rich phenylacridine unit connected by a spiro carbon atom to an electron-deficient 2,7-bis(diphenylphosphineoxide)-fluorene. In addition to a high ET value and adequate highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels, the key point in this molecular design is the suitable balance between hole and electron mobilities, which leads to a high-performance blue SL-PhOLED with an external quantum efficiency of 17.6% (current efficiency = 37.8 cd A−1 and power efficiency = 37.1 lm W−1) and a low Von of 2.5 V. This performance shows that the molecular design of the present host fulfills the criteria required for high-efficiency SL-PhOLEDs. The present performance is one of the highest reported to date for blue SL-PhOLEDs and more importantly shows the potential of such a molecular design to reach very high-performance single-layer devices. (10.1002/adom.201901225)
  DOI : 10.1002/adom.201901225
• Naphthyl-fused phosphepines: Luminescent contorted polycyclic P-heterocycles
  
  • Delouche Thomas
  • Mokrai Réka
  • Roisnel Thierry
  • Tondelier Denis
  • Geffroy Bernard
  • Nyulászi László
  • Benkő Zoltán
  • Hissler Muriel
  • Bouit Pierre-Antoine
  Chemistry - A European Journal, Wiley-VCH Verlag, 2020, 26 (8), pp.1856 –1863. This article presents the synthesis of a new family of naphthyl-fused phosphepines through Ni-mediated C-C coupling. Interestingly, the chlorophosphine oxide intermediate shows strong resistance toward oxidation/hydrolysis owing to a combination of steric hindrance and pnictogen interactions. However, it can undergo substitution reactions under specific conditions. The optical/redox properties and the electronic structure of these new π-systems were studied experimentally (UV/Vis absorption, emission, cyclic voltammetry) and computationally (TD-DFT calculations, NICS investigation). Taking advantage of the luminescence of these derivatives, a blue-emitting OLED has been prepared, highlighting that these novel π-conjugated P-heterocycles appear to be promising building blocks for solid-state lighting applications. (10.1002/chem.201904490)
  DOI : 10.1002/chem.201904490
• Universal host materials for red, green and blue high-efficiency single-layer phosphorescent organic light-emitting diodes
  
  • Lucas Fabien
  • Quinton Cassandre
  • Fall Sadiara
  • Heiser Thomas
  • Tondelier Denis
  • Geffroy Bernard
  • Leclerc Nicolas
  • Rault-Berthelot Joëlle
  • Poriel Cyril
  Journal of Materials Chemistry C, Royal Society of Chemistry, 2020, 8 (46), pp.16354-16367. Simplifying the structure of Organic Light-Emitting Diodes (OLEDs) has been for the last twenty years the purpose of many studies. However, despite these efforts, only a few materials provide high efficiency devices. We report herein efficient design strategies to construct universal host materials for red, green and blue Single-Layer Phosphorescent OLEDs (SL-PhOLEDs). The three materials investigated, SPA-2,7-F(POPh$_2$)$_2$, SPA-3,6-F(POPh$_2$)$_2$ and SPA-2-FPOPh$_2$, have been synthesized via an efficient approach and are constructed on the association of an electron rich phenylacridine unit connected by a spiro carbon atom to three different electron-deficient diphenylphosphineoxide-substituted fluorenes. Electrochemical, spectroscopic, thermal and transport properties are discussed. The position (C2 and C7 vs. C3 and C6) and the number (1 vs. 2) of diphenylphosphineoxide units on the fluorene backbone have been particularly studied to highlight the best combination in term of device performances. Red, green and blue SL-PhOLEDs (RGB SL-PhOLEDs) have been fabricated and characterized and their performances discussed. Of particular interest, we managed to reach a FIr6-based SL-PhOLED (with SPA-2-FPOPh$_2$) possessing an external quantum efficiency of 9.1% and a low threshold voltage (below 3 V). As far as we know, this is the first example of SL-PhOLED using this blue phosphorescent emitter. On the other hand, with notably a very high external quantum efficiency of 18% with FIrpic as sky blue emitter, SPA-2,7-F(POPh$_2$)$_2$ displays the highest overall performance in the series and the highest overall performance ever reported for RGB SL-PhOLEDs using a universal host. This not only shows that the association of phenylacridine and diphenylphosphineoxide units fulfils the required criteria for an universal host for high efficiency SL-PhOLEDs but also highlights that the arrangement of these fragments drives the device performance. (10.1039/D0TC04650G)
  DOI : 10.1039/D0TC04650G
• Dispersible Conjugated Polymer Nanoparticles as Biointerface Materials for Label-Free Bacteria Detection
  
  • Elgiddawy Nada
  • Ren Shiwei
  • Yassar Abderrahim
  • Louis-Joseph Alain
  • Sauriat-Dorizon Hélène
  • El Rouby Waleed M.A.
  • El-Gendy Ahmed
  • Farghali Ahmed
  • Korri-Youssoufi Hafsa
  ACS Applied Materials & Interfaces, Washington, D.C. : American Chemical Society, 2020, 12 (36), pp.39979-39990. Fast and efficient identification of bacterial pathogens in water and biological fluids is an important issue in medical, food safety, and public health concerns that requires low-cost and efficient sensing strategies. Impedimetric sensors are promising tools for monitoring bacteria detection because of their reliability and ease-of-use. We herein report a study on new biointerface-based amphiphilic poly(3-hexylthiophene)-b-poly(3-triethylene-glycol-thiophene), P3HT-b-P3TEGT, for label-free impedimetric detection of Escherichia coli (E. coli). This biointerface is fabricated by the self-assembly of P3HT-b-P3TEGT into core–shell nanoparticles, which was further decorated with mannose, leading to an easy-to-use solution-processable nanoparticle material for biosensing. The hydrophilic block P3TEGT promotes antifouling and prevents nonspecific interactions, while improving the ionic and electronic transport properties, thus enhancing the electrochemical-sensing capability in aqueous solution. Self-assembly and micelle formation of P3HT-b-P3TEGT were analyzed by 2D-NMR, Fourier transform infrared, dynamic light scattering, contact angle, and microscopy characterizations. Detection of E. coli was characterized and evaluated using electrochemical impedance spectroscopy and optical and scanning electron microscopy techniques. The sensing layer based on the mannose-functionalized P3HT-b-P3TEGT nanoparticles demonstrates targeting ability toward E. coli pili protein with a detection range from 103 to 107 cfu/mL, and its selectivity was studied with Gram(+) bacteria. Application to real samples was performed by detection of bacteria in tap and the Nile water. The approach developed here shows that water/alcohol-processable-functionalized conjugated polymer nanoparticles are suitable for use as electrode materials, which have potential application in fabrication of a low-cost, label-free impedimetric biosensor for the detection of bacteria in water. (10.1021/acsami.0c08305)
  DOI : 10.1021/acsami.0c08305
• Microstructural deformation observed by Mueller polarimetry during traction assay on myocardium samples
  
  • Tueni Nicole
  • Vizet Jérémy
  • Genet Martin
  • Pierangelo Angelo
  • Allain Jean-Marc
  Scientific Reports, Nature Publishing Group, 2020, 10, pp.20531. Despite recent advances, the myocardial microstructure remains imperfectly understood. In particular, bundles of cardiomyocytes have been observed but their three-dimensional organisation remains debated and the associated mechanical consequences unknown. One of the major challenges remains to perform multiscale observations of the mechanical response of the heart wall. For this purpose, in this study, a full-field Mueller polarimetric imager (MPI) was combined, for the first time, with an in-situ traction device. The full-field MPI enables to obtain a macroscopic image of the explored tissue, while providing detailed information about its structure on a microscopic scale. Specifically it exploits the polarization of the light to determine various biophysical quantities related to the tissue scattering or anisotropy properties. Combined with a mechanical traction device, the full-field MPI allows to measure the evolution of such biophysical quantities during tissue stretch. We observe separation lines on the tissue, which are associated with a fast variation of the fiber orientation, and have the size of cardiomyocyte bundles. Thus, we hypothesize that these lines are the perimysium, the collagen layer surrounding these bundles. During the mechanical traction, we observe two mechanisms simultaneously. On one hand, the azimuth shows an affine behavior, meaning the orientation changes according to the tissue deformation, and showing coherence in the tissue. On the other hand, the separation lines appear to be resistant in shear and compression but weak against traction, with a forming of gaps in the tissue. (10.1038/s41598-020-76820-w)
  DOI : 10.1038/s41598-020-76820-w
• Evaluating β-amyloidosis progression in Alzheimer’s disease with Mueller polarimetry
  
  • Borovkova Mariia
  • Bykov Alexander
  • Popov Alexey
  • Pierangelo Angelo
  • Novikova Tatiana
  • Pahnke Jens
  • Meglinski Igor
  Biomedical optics express, Optical Society of America - OSA Publishing, 2020, 11 (8), pp.4509. (10.1364/BOE.396294)
  DOI : 10.1364/BOE.396294
• Ultra-low-threshold continuous-wave and pulsed lasing in tensile-strained GeSn alloys
  
  • Elbaz Anas
  • Buca Dan
  • von den Driesch Nils
  • Pantzas Konstantinos
  • Patriarche Gilles
  • Zerounian Nicolas
  • Herth Etienne
  • Checoury Xavier
  • Sauvage Sébastien
  • Sagnes Isabelle
  • Foti Antonino
  • Ossikovski Razvigor
  • Hartmann Jean-Michel
  • Boeuf Frédéric
  • Ikonic Zoran
  • Boucaud Philippe
  • Grützmacher Detlev
  • El Kurdi Moustafa
  Nature Photonics, Nature Publishing Group, 2020, 14 (6), pp.375-382. Strained GeSn alloys are promising for realizing light emitters based entirely on group IV elements. Here, we report GeSn microdisk lasers encapsulated with a SiNx stressor layer to produce tensile strain. A 300nm GeSn layer with 5.4 at. % Sn, which is an indirect band-gap semiconductor as-grown, is transformed via tensile strain engineering into a direct band-gap semiconductor that supports lasing. In this approach the low Sn concentration enables improved defect engineering and the tensile strain delivers a low density of states at the valence band edge, which is the light hole band. We observe ultralow-threshold continuous wave (cw) and pulsed lasing at temperatures of up to 70K and 100K respectively. Lasers operating at a wavelength of 2.5 µm have thresholds of 0.8 kW cm −2 for ns-pulsed optical excitation, and 1.1 kW cm −2 under cw optical excitation. The results offer a path towards monolithically integrated group IV laser sources on a Si photonics platform. (10.1038/s41566-020-0601-5)
  DOI : 10.1038/s41566-020-0601-5
• Revealing Plasma-Surface Interaction at Atmospheric Pressure: Imaging of Electric Field and Temperature inside the Targeted Material
  
  • Slikboer Elmar
  • Acharya Kishor
  • Sobota Ana
  • Garcia-Caurel Enric
  • Guaitella Olivier
  Scientific Reports, Nature Publishing Group, 2020, 10, pp.2712. The plasma-surface interaction is studied for a low temperature helium plasma jet generated at atmospheric pressure using Mueller polarimetry on an electro-optic target. The influence of the AC kHz operating frequency is examined by simultaneously obtaining images of the induced electric field and temperature of the target. The technique offers high sensitivity in the determination of the temperature variation on the level of single degrees. Simultaneously, the evolution of the electric field in the target caused by plasma-driven charge accumulation can be measured with the threshold of the order of 10<SUP>5</SUP> V/m. Even though a specific electro-optic crystal is used to obtain the results, they are generally applicable to dielectric targets under exposure of a plasma jet when they are of 0.5 mm thickness, have a dielectric constant greater than 4 and are at floating potential. Other techniques to examine the induced electric field in a target do not exist to the best of our knowledge, making this technique unique and necessary. The influence of the AC kHz operating frequency is important because many plasma jet designs used throughout the world operate at different frequency which changes the time between the ionization waves and hence the leftover species densities and stability of the plasma. Results for our jet show a linear operating regime between 20 and 50 kHz where the ionization waves are stable and the temperature increases linearly by 25 K. The charge deposition and induced electric fields do not increase significantly but the surface area does increase due to an extended surface propagation. Additionally, temperature mapping using a 100 ?m GaAs probe of the plasma plume area has revealed a mild heat exchange causing a heating of several degrees of the helium core while the surrounding air slightly cools. This peculiarity is also observed without plasma in the gas plume. (10.1038/s41598-020-59345-0)
  DOI : 10.1038/s41598-020-59345-0
• Framework for the Simulation of Sensor Networks Aimed at Evaluating In Situ Calibration Algorithms
  
  • Delaine Florentin
  • Lebental Bérengère
  • Rivano Hervé
  Sensors, MDPI, 2020, 20 (16), pp.38p. The drastically increasing availability of low-cost sensors for environmental monitoring has fostered a large interest in the literature. One particular challenge for such devices is the fast degradation over time of the quality of their data. Therefore, the instruments require frequent calibrations. Traditionally, this operation is carried out on each sensor in dedicated laboratories. This is not economically sustainable for dense networks of low-cost sensors. An alternative that has been investigated is in situ calibration: exploiting the properties of the sensor network, the instruments are calibrated while staying in the field and preferably without any physical intervention. The literature indicates there is wide variety of in situ calibration strategies depending on the type of sensor network deployed. However, there is a lack for a systematic benchmark of calibration algorithms. In this paper, we propose the first framework for the simulation of sensor networks enabling a systematic comparison of in situ calibration strategies with reproducibility, and scalability. We showcase it on a primary test case applied to several calibration strategies for blind and static sensor networks. The performances of calibration are shown to be tightly related to the deployment of the network itself, the parameters of the algorithm and the metrics used to evaluate the results. We study the impact of the main modelling choices and adjustments of parameters in our framework and highlight their influence on the results of the calibration algorithms. We also show how our framework can be used as a tool for the design of a network of low-cost sensors. (10.3390/s20164577)
  DOI : 10.3390/s20164577