Several original point charge like electric field sources and a new tri-axial capacitive based electric field sensor have been designed to be associated together to build a new instrument able to characterize the electrical properties of the environment. The paper presents two fundamental features of the target electric imaging instrument: the characterization of the constituent parts of the system and the validation of the low-level data processing functions. The original electric field sources are composed of several conductive spheres with conical support so that they can be assimilated to point charges. The various arrangements of the sources can generate monopolar or multipolar electric fields. The tri-axial sensor is is integrated in a 2D scanning setup and used to map simultaneously the three components of the electric field generated by original electric field sources composed of several conductive spheres. The measured electric field images are compared to images calculated with an analytical model using the method of image charges. The agreement between measured electric field images and model validates both the original design of the sources and the geometrical features of the sensor which opens the door to application such as the detection of non-conductive buried object and smart detection with autoconfiguration.

Integrated gas sensors and measuring systems are desired devices in many domains, including large scales applications. One of the main issue still is their poor chemical selectivity despite the very wide diversity of developed systems. In this paper, we present our approach based on selectively adsorbing zeolite thin films. A full instrument has been developed with up to five transduction means based on a single adsorbing layer of zeolite. That layer is suspended on a large Mylar membrane capped with a functionalized Aluminum thin film. We present also an analytical mechanical model that allows estimating the instrument intrinsic possibilities.

Integrated gas sensors and measuring systems are desired devices in many domains, including large scales applications. One of the main issue still is their poor chemical selectivity despite the very wide diversity of developed systems. In this paper, we present our approach based on selectively adsorbing zeolite thin films. A full instrument has been developed with up to five transduction means based on a single adsorbing layer of zeolite. That layer is suspended on a large Mylar membrane capped with a functionalized Aluminum thin film. We present also an analytical mechanical model that allows estimating the instrument intrinsic possibilities.

In this paper, we show the integration steps we have undertaken for the integration of a recently proposed new principle for gas detection. Benefits of integration and co-integration of the miniaturized detectors with CMOS electronics will be the realization of arrays of selective detectors resulting in a new kind of electronic nose.

A Sensor to measure electric vector fields based on the Pockel effect and a sensor making good use of a search capacitor have been submitted to the same electric field excitations. Outputs of their analog electronics are further processed using a multi-channel dynamic signal analyzer (24 bits and 10 mHz to 100 kHz analysis bandwidth). Both AC and DC behavior have been addressed, the later with the help of an electric field mill. The direct comparison was made possible up to 100 kVm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> using a large enough electric field source and high voltage outputs amplifiers. This way, the sensors are operated at the same time, while occupying similar positions inside the electric field. Results expressed as a voltage transfer function in the AC mode exhibit a good coherence all along the analysis band. It highlights the different bandwidth of the two instruments nonetheless sharing three decades: the search capacitor working at low frequency while the electro-optic one is known to work at high frequency. Finally, the electric field mill used at a chopping frequency of 54 Hz induces a limitation for both sensors in the lower part of their measuring range, below a few hundreds of Vm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , while noise floors of each sensor are found well below a residual signal induced by the electric field mill rotation.

We demonstrate a new operation mode of thermal gas sensor based on thermal capacity extraction with identification algorithm. The system is a silicon microstructure covered with zeolites operated at constant temperature while stimulated by heat pseudo-random sequence. The proposed detection principle is demonstrated at room temperature and atmospheric pressure through the detection of gas water molecules with an hydrophilic FAU-type zeolite coating. The identification algorithm is a continuous-time closed-loop identification algorithm based on the instrumental variable principle.

Le succès de la plateforme youtube de partage de vidéos montre l’attrait du public et donc aussi des étudiants de nos filières scientifiques pour le support vidéo. C’est le point de départ d’un projet appelé TPELECTROSPI. Il a consisté à remplacer l’adage bien connu « un dessin vaut mieux qu’un long discours » utilisé dans les textes de TP pour expliquer les pratiques expérimentales par une version plus contemporaine « une vidéo vaut mieux qu’un long discours ». Cette évolution éditoriale a été l’occasion de remettre en cause certains fondamentaux des travaux pratiques : le texte de TP, le travail préparatoire et le compte-rendu par l’utilisation intensive d’outils de pédagogie numérique. Cette expérience a été appliquée pour un cours d’électronique analogique du second semestre de la mention « sciences pour l’ingénieur » de la licence « sciences, technologie, santé » de l’Université de Caen Normandie. Un questionnaire mis en place en fin de cours et les statistiques d’utilisation de la plateforme numérique ont permis de montrer l’intérêt du dispositif pour les étudiants. Cette expérience sera partagée avec les autres collègues du département pour une extension éventuelle à d’autres enseignements.

New concept of microfabricated thermal resonant gas sensor comprising of a cantilever-like thermal device covered with a selective zeolite layer associated to heat feedback electronics is presented. Sensing principle exploits the thermal resonant frequency shift caused by mass variations upon gas adsorption in the zeolite layer; the proof-of-concept is demonstrated by selective adsorption of water and ethanol in hydrophilic FAU type zeolite layer. Hollow silicon supporting structures were fabricated in order to enhance the zeolite to silicon mass ratio, thus improving the relative thermal mass variation under gas adsorption.

We demonstrate a new operation mode of thermal gas sensor based on thermal mass extraction with identification algorithm. The system is a silicon microstructure covered with zeolites operated at constant temperature while stimulated by heat pseudo-random sequence. The proposed detection principle is demonstrated at room temperature and atmospheric pressure through the detection of gas water molecules with an hydrophilic FAU-type zeolite coating.

This paper deals with the detection of non conducting objects by 2D-scanning of electric field variations. The principle relies on the measurement of the perturbations of a low frequency excitation electric field induced by the polarization of the object to be detected. These perturbations are measured thanks to an electric sensor and the excitation field is provided by a pair of electrodes. Finite elements method simulations are shown which illustrate the expected response of the system. The experimental setup is based on a horizontal planar (x-y) scanning table and on a synchronous detector locked at the excitation frequency. Images of the in-phase component of the vertical (zaxis) component of the electric field are obtained for two objects. These resulting images are discussed, allowing to expect further reconstruction of the non conducting objects shapes.

Microfabricated test structures are presented for the proof validation of a new chemical sensor concept. The proposed detection principle is based on time constant shift of a thermal device covered with zeolites when target species are adsorbed.

The concept of single input - multi output (SIMO) sensors is investigated for the purpose of chemical sensing and more precisely gas sensing. The measurement of a single gas is coupled to different outputs, each involving various transduction mechanisms. The concept is especially matched to gas sensing via selective adsorbing mechanism in an active layer, the mass or the electrical polarization of which both depend on the adsorbed amount. In this work, adsorbing layers are deposited on pairs of light membranes, each equipped with a meander shaped, resistive and temperature dependent layer. The latter provides heater - thermometer functions while the balanced pair assembly also makes them well matched to capacitive transduction and reading. This paper reports on such systems built either with industrial Mylar membranes or with Silicon based membranes covered with zeolite layers to introduce selectivity.

State of the art analogue signal processing allows multi-channel systems to be commonly used to process multi-sensor systems. Nevertheless, specific situations arise where the values from only one input - especially vector physical quantities - are needed, but signal strength and/or efficiency of transducers is not enough to produce sufficient signal to noise ratio, bandwidth, or dynamic range and therefore one output might not be enough. This contribution carefully analyses the case of magnetic flux density vector field sensing where the input consists of 3 wide-bandwidth components (DC to up to 1 MHz) measured around the same space point. The instrument consists of 6 pairs of sensors arranged to obtain the field components estimations around the same sampled point in space. millitesla range measurements were achieved with a noise spectrum of 20 - 50 pT/√Hz up to 1 MHz. These observations are discussed to evaluate the relevance of the concept to other physical quantities.

State of the art analogue signal processing allows multi-channel systems to be commonly used to process multi-sensor systems. Nevertheless, specific situations arise where the values from only one input - especially vector physical quantities - are needed, but signal strength and/or efficiency of transducers is not enough to produce sufficient signal to noise ratio, bandwidth, or dynamic range and therefore one output might not be enough. This contribution carefully analyses the case of magnetic flux density vector field sensing where the input consists of 3 wide-bandwidth components (DC to up to 1 MHz) measured around the same space point. The instrument consists of 6 pairs of sensors arranged to obtain the field components estimations around the same sampled point in space. millitesla range measurements were achieved with a noise spectrum of 20 - 50 pT/√Hz up to 1 MHz. These observations are discussed to evaluate the relevance of the concept to other physical quantities.

This contribution presents, in a reverse engineering like approach, the noise measurements and analysis of two commercially available magneto-resistive currents sensors respectively based on GMR (NVE Inc.) and AMR (SENSITEC GmbH) Wheatstone bridges. Comparison is done with the ultimate aim of designing low noise current conditioners for mini search coils based, magnetometers with galvanic insulation useful for further developments.

La problématique de la visualisation des champs électriques et magnétiques qui nous entourent est abordée sous l'angle d'expériences destinées au grand public. La démarche de cette présentation est analysée dans le détail, car elle s'appuie sur le ressort inhabituel de la poésie, pour susciter curiosité et interrogations. Au delà de cette opération typique de celles attendues lors de manifestations comme « la fête de la science », une transformation de la maquette initiale et de sa présentation formelle est proposée. Intégrable dans le cursus de formations de niveau L en physique et sciences de l'ingénieur, elle complète des manipulations de cartographie de champ électrique et magnétique jusqu'à l'obtention de cartographie du vecteur densité de puissance, ou vecteur de Poynting. Ainsi, la problématique de la détermination de la puissance transmise par une ligne sans contact, par échantillonnage spatial des champs électrique et magnétique autour des conducteurs constituant la ligne est abordée, au travers de mesures autour de dispositifs d'éclairage halogène à basse tension.

Ways to sense electric field using PZT capacitors are investigated. Duality rules a priori apply to material physics, linking polarization to magnetization properties, i.e. D(E) to B(H) curves, but no real electrical flux gate or charge gate does exist which would be the dual of the common flux gate magnetometer. The Landau - Khalatnikov equations are applied to ferroelectric materials subjected to both a DC and an AC pumping signal. They are solved to get the model of the PZT capacitors dynamics. They are experimentally investigated using the Sawyer Tower method. A second harmonic detection is a way to extract the DC excitation.