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Low power and high switching ratio are the development direction of the next generation of resistive random access memory (RRAM). Previous techniques could not increase the switching ratio while reducing the SET power. Here, we report a method to fabricate low-power and high-switching-ratio RRAM by adjusting the interstice radius (

Vector-borne diseases affecting livestock have serious impacts in Africa. Trypanosomosis is caused by parasites transmitted by tsetse flies and other blood-sucking Diptera. The animal form of the disease is a scourge for African livestock keepers, is already present in Latin America and Asia, and has the potential to spread further. A human form of the disease also exists, known as human African trypanosomosis or sleeping sickness. Controlling and progressively minimizing the burden of animal trypanosomosis (COMBAT) is a four-year research and innovation project funded by the European Commission, whose ultimate goal is to reduce the burden of animal trypanosomosis (AT) in Africa. The project builds on the progressive control pathway (PCP), a risk-based, step-wise approach to disease reduction or elimination. COMBAT will strengthen AT control and prevention by improving basic knowledge of AT, developing innovative control tools, reinforcing surveillance, rationalizing control strategies, building capacity, and raising awareness. Knowledge gaps on disease epidemiology, vector ecology and competence, and biological aspects of trypanotolerant livestock will be addressed. Environmentally friendly vector control technologies and more effective and adapted diagnostic tools will be developed. Surveillance will be enhanced by developing information systems, strengthening reporting, and mapping and modelling disease risk in Africa and beyond. The socio-economic burden of AT will be assessed at a range of geographical scales. Guidelines for the PCP and harmonized national control strategies and roadmaps will be developed. Gender equality and ethics will be pivotal in all project activities. The COMBAT project benefits from the expertise of African and European research institutions, national veterinary authorities, and international organizations. The project consortium comprises 21 participants, including a geographically balanced representation from 13 African countries, and it will engage a larger number of AT-affected countries through regional initiatives.

In this letter, we demonstrate the possibility to design a compact and ultralow power wireless node for environment sensing operating in the UHF band at 868 MHz. The wireless device is based on an ultralow power 8 b microcontroller associated with a digital temperature and relative humidity sensor. It communicates according to the backscattering principle to a software-defined radio (SDR) controlled by a graphical user interface developed in GNU Radio. The wireless node features a power consumption of 5 μA under 1.8 V, which is good enough for communicating data with a packet error rate of 10% at 110 b/s over a range of 30 m in an indoor environment for a transmitting power of 20 dBm. The design of the wireless node and its SDR-based detection system is validated with wireless measurements both in an anechoic chamber and in the indoor environment.

In this article, we present the design and realization of an electronically rewritable RF encoding particle (REP) for chipless RFID applications. This (REP) resonator geometry is integrated with two conductive bridging random access memory (CBRAM) based non-volatile RF switches, and could be electronically programmed using DC pulses to any of possible four resonant states to represent two bits of information. Emerging additive manufacturing (AM) technique based thermal transfer printing is utilized for the realization of this resonator on flexible and low cost Polyethylene terephthalate (PET) substrate. At present the size of the REP is such that five such REPs could be arranged on a standard credit card size tag. Also this REP encodes the most number of bits reported among non-volatile electronically rewritable REPs for chipless RFID applications - 2 bits, till date.

In this paper, a simple solution allowing continuous actimetry with an uniaxial magnetometer is presented. Worn on the wrist to monitor the forearm tilt, it can estimate the instantaneous metabolic-equivalent-of-task during physical activity. Autonomous acquisition and data transfer are managed by a radio frequency identification chip supporting the near field communication (NFC) standard. Thus, the solution can transfer measurements to an NFC-enabled device (computer and smartphone) that runs a custom algorithm. The algorithm output signal was indirectly calibrated to an accurate calorimetry device to display the real energy expenditure of the user during the physical activity session.

We present an electronically rewritable chipless RFID tag based on integrated nonvolatile Conductive Bridging Random Access Memory (CBRAM) RF switches. CBRAM is a nonvolatile memory technology, which is identified as an innovative RF switching solution in this decade. Reconfigurable resonator or RF encoding particle (REP) used in this tag is a closed-loop resonator integrated with two switches each to tune its electrical length, and encodes three states each, to represent more than one bit per REP. Presented tag is composed of three such REPs to represent a total of 27 unique states. This chipless RFID tag with CBRAM switches could be written/rewritten electronically using DC voltage pulses, to encode a desired code from a given combination. Thermal impression transfer printing is utilized for printing metallic layers of the presented chipless tag. Complete fabrication steps of presented tag with integrated CBRAM switches are carried out without any “clean room” processes. An insight to working mechanism of presented rewritable REPs using electrical models is included in this article. Proof of concept of a potential hybrid data encoding technique combining frequency shift coding and Radar Cross Section (RCS) magnitude level coding, through experimental studies, for presented REPs, is also given herewith.

International audience; In this article we present the concept of a practical approach to realization of a fully passive electronically rewritable chipless RFID tag. Integrated non-volatile and solid state Conductive Bridging Random Access Memory (CBRAM) based Metal-Insulator-Metal (MIM) switches are used to realize the rewritable functionality. A solution to the primary challenge of requirement of obtaining very low ON states resistances (~ < 10 Ω) in case of an RF switch, for efficient operating conditions is addressed in this paper. Here we propose a reconfigurable resonator design with a ground plane, which could operate efficiently for higher ON state resistances (~ > 100 Ω) of a CBRAM/MIM RF switch. A technique of data encoding in electronically rewritable dipole resonators, by effectively modulating the impedance states of integrated CBRAM/MIM switches is presented herewith in detail. This example is presented through a model design of a 3bit rewritable chipless RFID tag.

International audience; This paper introduces a flexible UHF RFIDsensor to detect food quality. This sensor is based on aninterdigitated capacity included in a RFID antenna on which isdeposited a layer of vegetal biopolymer. Thus, depending on thefood spoilage, electromagnetic coupling between the capacityand the biopolymer is used to modulate adaptation coefficientbetween chip and antenna of the RFID tag. This study isvalidated by experimental measurements of RFID-sensorexposed to real food gas environment in the process ofdegradation.

International audience; This paper address the advantage and additional functionalities obtained by using integrated nonvolatile nano-ionic conductive bridging metal-insulator-metal (MIM) switches for rewritable chipless RFID applications. Improvement in reliability and ease of fabrication on using Nafion as an ion-conductor for MIM switching applications is discussed. A brief review of devices realized using the proposed technique is given. A novel idea of realization of a shape and frequency rewritable resonator structure for chipless RFID applications is also discussed with the help of full wave electromagnetic simulation studies.

We report the design of a passive UHF RFID sensor compliant with the EPC Gen2 standard for tilt and temperature monitoring of fragile objects during transportation. The solution is based on the combination of a Farsens Rocky100 IC and a 3-axis accelerometer ADXL362 IC embedding a temperature sensor. The design is validated by simulation, measurement of the reading performance with a dedicated bench, and test of the RFID sensor in practical situations.

This paper reports the fabrication of capacitive humidity sensors by integrating a graphene oxide sensing layer inside paper substrates. Graphene oxide sheets were self-assembled on the papers’ fibers. A comparative study between several sensors with different concentrations of graphene oxide and different processing times in the graphene oxide suspension is reported. Its aim is to optimize the sensing layer in terms of concentration and thickness towards the fabrication of highly sensitive and porous sensors. The morphology of the fabricated sensors was characterized using scanning electron microscopy, their structure and chemical composition using Raman and infrared spectroscopies. The washability and mechanical strength of the graphene oxide coated paper were tested in water and in an ultrasonic bath. Last, the sensing capabilities of the fabricated devices were tested for a relative humidity ranging from 30% to 90% RH. The optimal sensor is highly porous, hydrophobic and exhibits a good response towards humidity with a low hysteresis. This work presents a low cost alternative for the use of polymers and coated-papers as substrates for flexible electronics. It is also a first step towards the integration of flexible electronics into substrates, which enables the fabrication of highly porous, economical and flexible devices ideal for air flow monitoring, e-dressings and e-textiles.

International audience; In this article, we present the design and results of an electronically re-writable chipless RFID tag on paper substrate. This tag consists of two resonators build around a modified shorted dipole, integrated with a non-volatile Metal-Insulator-Metal (MIM) switch, which tunes the electrical length of each resonator to resonate at two different frequencies, depending on state of the switch. One can electronically reconfigure the tag using low power DC pulses to change its RF signature. The integrated MIM switch has a layer architecture of Silver-Nafion-Aluminum, formed exclusively using an in-house process in ambient laboratory conditions, notably without the use of any 'clean room' facilities. Operating mechanism of the tag is validated with the help of developed electrical equivalent model. This study proves the concept of realizing 'electronically reconfigurable' chipless tags on flexible and low cost substrates, with a fabrication process compatible with mass production.

This review discusses the recent developments of flexible chemiresistive gas sensors, focusing on the main materials and fabrication techniques. This article provides a detailed description of the substrates used in the flexible gas sensing industry. It also highlights the main challenges faced when integrating a sensing layer on paper, textile or polymeric substrates. A detailed study of the sensing materials in terms of structural properties and sensing mechanisms is presented. This study uses examples of gas sensors to explain the sensing mechanisms and to emphasize the functionalization effect on the sensing performance of a material. It also highlights the exceptions in polymers sensing behavior. Since flexible substrates can’t sustain high temperatures, the main techniques used to fabricate flexible gas sensors are explained such as coating, printing, physical vapor deposition, in situ-growth, in situ-polymerization and chemical vapor deposition. The last technique, which requires high temperatures, is mostly used prior to transferring a sensing layer to a flexible substrate. At the end, the main challenges facing the flexible gas sensing technology are pointed out.

Flexible electronics on paper is currently a challenging area of research. The use of an economical and ecological substrate, such as paper, has significant potential compared to a plastic substrate, such as PET (Polyethylene Terephthalate) or Kapton® (Polyimide). However, the roughness and tearing of paper due to moisture and temperature during operation constitute major technical challenges, considering the potential application in electronics. The use of printing techniques, such as gravure, flexographic, screen, offset, inkjet, conductive and dielectric inks, and organic polymers, all of which have different viscosities suitable for machine deposition, may allow to electronic devices on a paper substrate; example products using this technology include flexible batteries, solar cell, displays, and biomedical devices. This technology only presents a small number of disadvantages, which include poor conductivity, expensive materials, and difficulties with subtractive batch processes, such as photolithography and vacuum processes. In this article, the authors chose an unconventional way to reduce the impact of these disadvantages by adapting technological processes of microelectronics (i.e., photolithography, metal vapour deposition, electroplating, and etching) for use on a standard paper substrate.

We report the design and first results of a reconfigurable RF-encoding particle (REP) for chipless RFID tag, based on a Nafion conductive-bridging random-access memory cell. The developed tag consists of a modified shorted dipole as REP, equipped with a copper–Nafion–aluminum metal–insulator–metal (MIM) nonvolatile ionic-bridging switch. The MIM switch is similar to an RC parallel network, which tunes the electrical length of the resonator. The chipless tags switch between two different resonant frequencies, in the set and reset states of the switch. An electrical model is also developed for the REP to explain the mechanism of switching. The experimental results are in close agreement with the simulation results using commercial electromagnetic simulators. This letter is a proof of concept of electronically reconfigurable chipless tags based on integrated switches which have the potential to be directly printed along with the tag.

International audience; We report a novel fully printed RFID based sensor fabricated on paper substrate. The sensitive material is wheat gluten which is a biopolymer having electrical parameters correlated with relative humidity (RH). The sensor is validated with simulation and measurement results varying climatic conditions.

This letter reports the design and development of a conductive bridging RF switch with simple fabrication steps without the use of any clean room technologies. The reported device is a fully passive shunt mode RF switch on a co-planar waveguide transmission line, which operates in the dc-3GHz range. This particular topology is chosen in contemplation to limitations imposed by the chosen realization process. The device is based on a metal-insulator (electrolyte)-metal structure, with copper- Nafion-aluminum switching layers. S 21 switching between -1 dB (RF-ON) and -16 dB (RF-OFF) is demonstrated till 3 GHz by the device. Dc pulses in the range between 18 V/0.5 mA and -20 V/0.1 A are used, respectively, to SET and RESET the switch, and the instantaneous power consumed for SET and RESET is, respectively, 1.7 μW and 3 mW. The SET and RESET state dc resistances of the switch are observed as 2 Ω and 2 MΩ subsequently. The model is initially simulated using commercial finite element method-based electromagnetic modeling tool and validated experimentally.

International audience; This study reports the design and experimental results of a fully-passive solid-state RF switch based on the Conductive Bridging Memory Technology, popularly known as CBRAM. The developed device is a shunt mode RF switch based on a Metal-Insulator-Metal (MIM) structure with Copper-Nafion-Aluminum switching layers on a Coplanar Waveguide (CPW) transmission line, operational in the DC to 3GHz range. DC pulses in the range +12V to-20V are used to operate the switch. The design is initially simulated using the FEM based CST microwave Studio and then realized and validated on a low cost FR4 substrate, and without using any sophisticated clean room technology.

A low-cost passive UHF RFID tag-based sensor is presented. The proposed tag-based sensor comprises a dual-feed patch antenna incorporated with passive sensor and passive RFID chips operating at UHF RFID bands. By introducing the passive sensor (i.e. resistive sensor nodes) in one of the tag antenna feed, low-cost wireless nodes with radio frequency identification and sensing capabilities are implemented. To remotely record the sensed data at any arbitrary distance from the reader, the other feed of the tag antenna is incorporated with only RFID chip and it serves as a reference node. By measuring the difference of the required minimum power transmitted by the reader to wake-up the RFID chips in both the reference and sensor nodes, the reader then can extract the sensed data (i.e. temperature) at the tag location.

The fabrication and the performance of PMMA resistive switching device have been studied by using FR-4 (copper), PMMA (poly methyl methacrylate) and aluminum as the active anode, the solid electrolyte and the inert cathode respectively. By etching the copper surface with the acid solution [4HNO3 + 11H3PO4 (98 %) + 5CH3COOH] at 60 °C for 2 min, a good performance of Cu/PMMA/Al device, which can switch until 2300 cycles, has been realized. The spin rate for forming the PMMA coating plays a decisive role in the performance of Cu/PMMA/Al device. The best performance of the Cu/PMMA/Al device was obtained only when the spin rate of deposition of PMMA reached 4000 rpm (low thickness).

RFID (Radio Frequency Identification) technology has considerably grown in the past few years and is nowadays sought to be implemented for the identification of products and for traceability in the agrifood sector, ensuring food safety and quality. RFID is now considered as the worthy successor of the barcode with a foreseen expansion not only in the agrifood sector, but also in industrial sectors for environmental monitoring (temperature, relative humidity and luminosity) through namely WSN (Wireless Sensor Network) and WST (Wireless Sensor Technology). Research studies are being progressively performed in the objective of coupling sensors to the RFID technology. This interfacing would lead to a better monitoring of packaging headspace by means of the development of different sensors, as well as their coupling to RFID tags through the microchip or directly to the RFID antenna. The present work gives an overview of the basics of the RFID technology, the existing sensors and the ones being developed to be interfaced with the technology, as well as the existing RFID sensor tags. The presented literature studies, mainly in the agrifood sector, demonstrate how RFID may meet our needs for a better monitoring of food quality by coupling radio frequency communication and traceability. The implementation of sensors which is a very new technology being studied and concomitantly developed may lead to a better detection of food degradation markers and thus to a reduction in food loss which is one of the world's major issue.

Nosocomial infections are contracted in a hospital or health care facility. Bacterial cause is the most common in 87% of cases. Studies have been conducted for the detection of these bacteria. The aim of this biosensor is to make an early detection tool, easy to use, reliable, not invasive and low cost. The goal is to detect in real time and simultaneously in a small amount of body fluids such as urine, sweat or saliva, the major bacterial pathogens causing these diseases: Escherichia Coli, Pseudomonas aeroginosa, Acinetobacter baumannii, Staphylococcus aureus and Clostridium difficile.

The use of wheat gluten as sensing material to detect carbon dioxide is a promising approach. The dielectric properties of wheat gluten are modified in contact with carbon dioxide gas at high relative humidity (90%) and at a temperature of 25 °C due to a structural change in the sensing material, where amino groups act as receptors to carbon dioxide molecules. In the present study, the effects of carbon dioxide on the electrical and dielectric properties of wheat gluten at 20% and 90% of relative humidity (usually found in food packaging) are determined and discussed. At 90% of relative humidity, a linear increase of the dielectric permittivity and dielectric loss was observed with a significant hysteresis which increased with the number of carbon dioxide treatment cycles. One of the significant results is the increase in the dielectric permittivity from 7.01 ± 0.07 to 12.02 ± 0.03 with a sensitivity of 31.38 ± 0.06 fF/%CO2 measured at 868 MHz. The developed sensor is sought to be integrated in the design of UHF-RFID (ultra-high frequency − radio frequency identification) systems working at 868 MHz.

The innovative use of gelatin as a temperature sensor based on capacitance was studied at a temperature range normally used for meat cooking (20–80 °C). Interdigital electrodes coated by gelatin solution and two sensors of different thicknesses (38 and 125 µm) were studied between 300 MHz and 900 MHz. At 38 µm, the capacitance was adequately measured, but for 125 µm the slope capacitance versus temperature curve decreased before 900 MHz due to the electrothermal breakdown between 60 °C and 80 °C. Thus, for 125 µm, the capacitance was studied applying 600 MHz. Sensitivity at 38 µm at 868 MHz (0.045 pF/°C) was lower than 125 µm at 600 MHz (0.14 pF/°C), influencing the results in the simulation (temperature range versus time) of meat cooking; at 125 µm, the sensitivity was greater, mainly during chilling steps. The potential of gelatin as a temperature sensor was demonstrated, and a balance between thickness and frequency should be considered to increase the sensitivity.

An interdigital capacitor (IDC) system was designed in order to provide a controlled high exposure (high surface/thickness ratio) to the environmental atmosphere of a sensing layer of which the dielectric properties were identified by a finite element method simulation and validated using a common parallel plate capacitor technique. The dielectric properties of one of the most sensitive and widely available plant polymers in nature: wheat gluten (WG) proteins were determined at ultra high frequency (500 MHz-1000 MHz) at 25 degrees C and at two different values of relative humidity (RH). Increasing relative humidity from 20% RH to 80% RH increased the dielectric loss and permittivity of wheat gluten from 0.39 +/- 0.01 to 0.84 +/- 0.02 and from 5.01 +/- 0.06 to 7.07 +/- 0.18, respectively. This effect was discussed in the light of wheat gluten composition (constituting amino acids), structure (high molecular weight, proteins unfolding and mobility) and water content (adsorbed water-bonding state). In addition to RH, two other analytes known as food quality markers, carbon dioxide (CO2) and ethanol were studied in terms of sensitivity. The sensitivities of 10.0 +/- 0.4 fF/%RH, 31.38 +/- 0.06 fF/%CO2 and 25.50 +/- 0.05 pF/%ethanol obtained should pave the way for the development of innovative green radio frequency identification (RFID) tags using renewable, cheap and biodegradable plant polymers as gas and vapor sensors. The sensors are intended to be interfaced to low-cost, ultra high frequency, passive, RFID tags for monitoring food quality and freshness volatile markers in packaging headspace.

The fabrication process of anodic aluminium oxide (AAO) on a paper-based substrate is challenging because the use of a highly economical, conformable and ecological substrate. This process is based on a simple, cost-effective, self-ordering anodization of aluminium, which yields a vertically aligned and a highly ordered nanoporous structure. The manufacturing process on a flexible substrate with the use of phosphoric acid is described, and a capacitive sensor produced on this layer is investigated versus the humidity concentration and the frequency. The AAO morphology and the structure obtained were analysed, and the electrical properties of the sensing layer were investigated, using a 4192A LF network analyser in a climatic chamber. The surface conduction mechanism and the effect of humidity on the dielectric properties of a porous anodic aluminium oxide are discussed.

In this paper we focus on the design of a miniaturized implantable RFID sensor to enable remote identification and sensing for orthopedic prosthesis dedicated to hips and knees. The current issues to overcome in the world of orthopedic surgery are a better tracking of patient's implants integrity during the whole cycle life of the prosthesis. Second, in case the prosthesis should be changed, it would be interesting to have a clear picture of the prosthesis model before the surgical operation to be sure that no surprise arises during the operation. The RFID is a technology which can perfectly match these required key points. A passive RFID tag doesn't need any local battery supply since it harvests energy from the electromagnetic (EM) field of the reader. In its simplest form it is composed of an antenna connected to a chip. The technology involved is shared mainly between HF technologies based on near field communication principle, and UHF technology (867 MHz in Europe). In this paper we study the possibility to design an implant based on UHF RFID tag. Even though, the wireless link losses are higher in human body tissues, the main interest to compare with HF RFID is the higher read range capability (up to several meters) which is more compatible with the aforementioned application for which a detection distance of 50 cm is needed. In order to sense if the prosthesis is properly inserted within the bone, and if it doesn't show any tilt, a pressure sensor is attached to the dedicated RFID IC SL900A from AMS with no additional components as shown in Fig. 1 (a). In order to miniaturize the implant, a ceramic chip antenna operating around 900 MHz is connected to the AMS IC (see Fig. 1 (b)). The whole assembly made of the pressure sensor, the IC and the antenna is coated with PDMS silicon-based resin. This makes a flexible 20×20mm2 RFID-enabled sensor operating at a distance in free space up to 0.6 meter in passive mode as shown in Fig. 1 (c).

Nowadays, flexible electronics is a challenging research area cause of the increase of electronics component request for “the internet of things”, the food safety and the medical diagnostic applications. In our research, we work with an unusual substrate for microtechnologies such as paper, which is flexible, brittle, and biodegradable. Also, it can be folded, cut, perforated, crumpled, etc. This article focuses on monitoring porous Anodic Aluminum Oxide (AAO) layer on paper-based substrate for the detection of humidity. Porous AAO is a material with cylindrical pore geometry and high aspect ratio. Further, this material has many advantages, such as, easy fabrication, pore diameter's uniformity with high pore density (1011/cm2) and its use like humidity sensors. In summary, the AAO process fabrication on paper substrate is challenging causes of his ease of implementation, cost-effective and the use of a highly economical, conformable and ecological substrate. In this study, an experimental setup had been developed to anodize an aluminum layer deposit on flexible substrate by using phosphoric acid. Various anodization parameters (voltage, current density, temperature and concentration) have been investigated to obtain an AAO layer with good electrical properties and high reliability on flexible substrate. An interdigital capacitance has been deposited on the best AAO layer produced to fabricate a moisture sensor. The different sensors produced had been characterized versus humidity concentration and frequency in a climatic chamber. Depending on the AAO morphology parameters, the average sensitivity can be tuned from 0.8 pF/RH% to 9 pF/RH%.

International audience

The use of radio frequency identification (RFID) technology is gaining in popularity. Contactless payment, transportation cards, or even anti-shop-lifting alarms are daily used examples of this technology. These wireless solutions that store identification data even find their application to replace the barcode label. An RFID tag is placed on an object and store more data that just its model identifier like its serial number, producer, expiry date, ... In industrial field, the cost of these so-called passive tags is reduced by the absence of battery. They generally use the EPC (Electronic Product Code) protocol of generation 2, branded as “RAIN”, which works in UHF band (Ultra High Frequencies). To provide more information on the tagged product, this communication protocol allows tag designers to add several sensing features. Thus, the reading can bring back more information on the state of the spoiling product. Today, many sensing tag solutions designed by academics still exceed regulatory limits imposed by governments in terms of power and/or frequency. Our goal is to propose a solution that is suited to industrial partners needs. To do so, we design a sensing tag whose measurement process is compliant with governmental guidelines and propose a signal conditioning compatible with conventional and standard-compliant UHF RFID readers. In this work, the application targets the field of agri-food logistics. Indeed, the sensor-tag measures a combination of volatile elements released in the closed food packaging and gives indications of the degradation of the food. In collaboration with multiple industrial partners, several validations were conducted in an operational environment., L’utilisation de la technologie d’identification par radiofréquence (RFID) gagne en popularité. Le paiement sans contact, les cartes de transports, ou encore les alarmes anti-vols sont des exemples avec une utilisation quasiment journalière. Ces solutions de stockage d’information d’identification sans fil trouvent même leurs applications pour remplacer le code-barre par une étiquette RFID. En effet, pour une utilisation industrielle, le coût de ces étiquettes dites passives est réduit par l’absence de batterie. Elles utilisent généralement le protocole EPC de génération 2 qui fonctionne en bande UHF (Ultra-Hautes Fréquences). Pour apporter plus d’information sur le produit étiqueté, ce protocole de communication autorise les concepteurs d’étiquette à y adjoindre une fonction capteur. Ainsi, la lecture peut remonter des informations sur l’état du produit. Aujourd’hui encore, beaucoup de solutions d’étiquettes-capteurs conçus par le milieu académique dépassent les limites imposées par les gouvernements en termes de puissance et/ou de fréquence. Notre but est de proposer une solution adaptée au terrain des professionnels. Pour cela, nous avons conçu une étiquette-capteur dont le processus de mesure est conforme aux directives gouvernementales et proposons un conditionnement du signal compatible avec les lecteurs RFID UHF conventionnel et standard. Dans ce travail, l’application cible le domaine de la logistique agro-alimentaire. En effet, l’étiquette-capteur mesure une combinaison d’éléments volatiles libérés dans l’emballage alimentaire fermé donnant alors un état de la dégradation de l’aliment. De concert avec un partenaire industriel, une validation a été menée dans un environnement opérationnel.

Mycotoxin contamination is a threat to the health and life of Humans and animals. One of the most common mycotoxin contaminating feed and foodstuffs is Ochratoxin A (OTA). OTA has a chronic toxic effect and has proved to be mutagenic, nephrotoxic, teratogenic, immunosuppressive, and carcinogenic molecule. Aptamer with their specific affinity for OTA was used in this paper to create an analytical technique. Several methods have been reported for the determination of OTA in foods. However, most of these methods could not be applied to a complex food as green coffee because the interfering native fluorescent molecules made the quantification very difficult. In this work, we mixed two separations based techniques to identify and quantify OTA in green coffee. Aptamer assisted ultrafiltration as separation technique based on the size of molecules was applied to separate the free OTA; the quantification of OTA was established by a high-performance liquid chromatography (HPLC-FD) with LOD of 0.05 ng/mL for OTA. Artificially contaminated green coffee displayed a good range of OTA recoveries up to 97.7%. The selected aptamer was used as a biorecognition element to functionalize a capacitive sensor for OTA detection. A capacitive aptasensor was developed for quantification of OTA based on modified anodized aluminum oxide with a LOD of 10-4 ng/mL. This method can be applied to the quantitative determination of OTA in green coffee at levels below the maximum levels proposed by the European Commission for green coffee (0.25 ng/mL). It also confirm that aptamers can be used as biorecognition element in diagnostic assays with commercial application for mycotoxin analysis. To our knowledge, it is the first label-free and electric capacitive aptasensor used to detect the OTA.; La contamination par les mycotoxines est une menace pour la santé et la vie des humains et des animaux. L’Ochratoxine A (OTA) est une mycotoxine des plus courantes qui contaminent les aliments. L'OTA a un effet toxique chronique et s'est révélée mutagène, néphrotoxique, tératogène, immunosuppresseur et cancérogène. Il est donc important de pouvoir détecter la présence de cette mycotoxine. Certains aptamères ont une affinité spécifique pour l’OTA et peuvent être utilisés pour créer une technique analytique. Plusieurs méthodes ont été décrites pour la détermination de l'OTA dans les aliments. Cependant, la plupart de ces méthodes ne pouvaient pas être appliquées à un aliment complexe tel que le café vert car les produits fluorescents interférents natifs du grain de café rendaient la quantification très difficile. Dans ce travail, nous avons mélangé deux techniques basées sur la séparation pour identifier et quantifier l'OTA dans le café vert. L'ultrafiltration assistée par aptamère comme technique de séparation basée sur la taille des molécules a été appliquée pour séparer l'OTA libre. La quantification de l'OTA a été réalisée par chromatographie en phase liquide à haute performance (HPLC-FLD) avec une limite de détection (LOD) de 0,05 ng/mL pour l'OTA. La récupération de l’OTA dans le café vert artificiellement contaminé présentait une bonne gamme de récupération jusqu’à 97,7%. L’aptamère sélectionné a ensuite été utilisé pour fonctionnaliser un support flexible d’alumine poreuse afin de former un aptacapteur capacitif, facilement manipulable, et spécifique envers l’OTA. Une preuve de concept a été développé pour la quantification de l’OTA et les premiers résultats ont montrés une limite de détection (LOD) de 10-4 ng/mL. Cette méthode a pu être appliquée à la détermination quantitative de l'OTA dans le café vert à des niveaux inférieurs aux niveaux maximaux proposés par la Commission européenne pour le café vert (0.25 ng/mL). Cette étude confirme également que les aptamères peuvent être utilisés comme élément de bioreconnaissance dans les tests de diagnostic ayant une application commerciale pour l'analyse des mycotoxines. À notre connaissance, il s'agit du premier aptacapteur capacitif électrique sans marquage utilisé pour détecter l'OTA.

In 2017, it was estimated that 425 million people worldwide had diabetes. The main reason for this skyrocketing number is related to the current socio-economic context of the world with global expenses reaching 1.3 billion dollars a year with estimates reaching up to 2.1 billion dollars by 2030 (Bommer et al., Diabetes Care, 2018). Above all physiological unbalances, this disease can cause many side effects if left untreated, one of them being chronic wounds, wounds that don’t follow the usual healing process. Among the different types of chronic wounds is diabetic foot ulcers (DFUs), with a prevalence of 6.3% (Sen, Advances in Wound Care, 2019) and a lifetime risk for the diabetic population as high as 25% (Boulton et al., The Lancet, 2005). These wounds have many factors involved in the permanent inflammation state that they are in, one of them being matrix metalloproteinases (MMPs) zinc endopeptidases with various roles.This project is focused on the development of a smart dressing for the monitoring of DFUs. This monitoring is done by measuring the concentration of a key enzyme in the inflammation process, MMP9 or Gelatinase B. This system is based on the use of porous alumina functionalized with a Biological Recognition Element (BRE) able to detect MMP9.The first part of the project is the search for BREs based of the screening of camelid antibodies (VHHs) or peptide libraries by phage display. Then, the project focuses on the development of two prototypes of capacitive biosensors, one for the study of the functionalization of a conventional anti-MMP9 antibody, the other with the use of a third-party VHH and its target, GFP. These two proofs-of-concept will be useful for the continuity of the project.; En 2017, il a été estimé que 425 millions de personnes souffraient de diabète. Les raisons de ce boom, liées au contexte socio-économique actuel, représentent une dépense globale de 1.3 milliard de dollars par an avec des estimations atteignant jusqu’à 2.1 milliards de dollars en 2030 (Bommer et al., Diabetes Care, 2018). Au-delà de dérèglements physiologiques, cette maladie peut engendrer de nombreux effets secondaires si elle n’est pas traitée correctement, notamment la formation de plaies chroniques, plaies ne suivant pas le schéma de cicatrisation habituel. Parmi les différentes plaies chroniques se trouvent les plaies du pied diabétique avec une prévalence globale de 6,3% (Sen, Advances in Wound Care, 2019) et une probabilité de développement chez les personnes diabétiques de 25% (Boulton et al., The Lancet, 2005). Ces plaies possèdent de nombreux facteurs participant à ce phénomène de pérennisation, dont les métalloprotéases matricielles ou MMP, endopeptidases à zinc aux rôles variés.Ces travaux de thèse s’intéressent à l’élaboration d’un dispositif de pansement connecté pour le suivi de l’évolution des plaies du pied diabétique. Ce suivi se fait par mesure de la concentration d’une enzyme clé dans les phénomènes d’inflammation de ce type de plaie, la métalloprotéase matricielle 9 (MMP9), également appelée Gelatinase B. Ce système se base sur l’utilisation d’alumine poreuse fonctionnalisée avec un Élément de Reconnaissance Biologique (ERB) capable d’interagir avec la cible, MMP9.Dans un premier temps, une recherche d’ERB affine pour la cible est étudiée. Cette recherche se base sur un screening de banques d’anticorps de camélidé (VHH) et de banques peptidiques par la méthode de phage display.La suite du projet se focalise sur l’élaboration de deux prototypes de biocapteurs capacitifs, l’un avec l’étude de la fonctionnalisation d’un anticorps conventionnel anti-MMP9, l’autre avec l’utilisation d’un VHH tiers, affine pour la GFP. Ces deux preuves de concept seront utiles pour la continuité du projet.