Modélisation par Eléments Finis d'une Ligne à Retard à Ondes de Love

Les microcapteurs acoustiques à ondes de surface ont largement démontré leurs performances pour détecter des composés chimiques et biologiques en milieux gazeux et liquides. Plus précisément, les dispositifs à onde de Love font l’objet d’une attention particulière en raison de leurs bons résultats en milieux liquides notamment. La conception de ces dispositifs nécessite une phase de modélisation et de simulation indispensable à leur mise en œuvre opérationnelle. Cependant, à ce jour, en raison de la complexité de ces dispositifs, la plupart des modèles présentés simulent quelques caractéristiques de propagation de l’onde. La vitesse de phase est plus particulièrement calculée afin de permettre l’estimation de la sensibilité à l’effet de masse des capteurs. Nous proposons dans cette communication d’aller au-delà des modélisations classiques en présentant l’utilisation d’un logiciel à éléments finis pour un dispositif à ondes de Love. Nous présentons ainsi une modélisation globale permettant l’estimation d’un large champ de paramètres lors du fonctionnement du dispositif. Les premiers résultats seront présentés et analysés. Les perspectives et potentialités de l’utilisation de ce logiciel pour les capteurs à ondes de Love seront également abordées

Novel Microwave Gas Sensor using Dielectric Resonator With SnO2 Sensitive Layer

International audienceA new generation of passive gas sensors that works at millimeter-wave frequency (50 to 70 GHz) incorporating sensitive material is presented. The sensor uses a microwave planar dielectric resonator operating with whispering gallery-modes. The dielectric resonator (DR) is covered by SnO2 thin film as sensitive layer. A gas adsorption makes the SnO2 effective dielectric parameters changing namely its permittivity. Such changing modifies the resonance frequency of the resonator. Here, the proof of concept is demonstrated thorough full wave simulations. This sensor is a passive circuit and has great potential for wireless sensing network applications

Study of Gaseous Compounds Adsorption with a Love Wave Sensor Based on Molecularly Imprinted Polymeric Thin Film

This work exhibits a Love wave sensor combined with molecularly imprinted polymer (MIP). The final aim is for specific detection of colon cancer biomarkers. This paper deals with the validation of a MIP thin film’s coating process, allowing high sensitivity of the resulting microsensor. After a brief description of the acoustic sensor and of the MIP coating process, the functionality of the resulting device is proved with electrical characterization. Deep characterization of the thin film - morphology and print effect - is proposed, based on dynamical responses observed under exposure to different vapors. Experimental results point out a good reproducibility of polymeric films. MIP layers increased responses of sensors to vapors by a factor 3 to 4 compared to bare devices or to devices coated with non-imprinted polymer (NIP). For example, exposure to 4000 mg/m3 (2126 ppm) of ethanol in nitrogen induced a frequency shift of -1.4/-0.4 kHz with MIP/NIP-coated sensor, respectively

Love Wave Sensor Based on Thin Film Molecularly Imprinted Polymer: Study of VOCs Adsorption

ABSTRACT The overall objective of this work is to develop and to validate a quantitative, non-invasive diagnosis tool to monitor the efficiency of colorectal cancer chemotherapy. This paper deals with the validation of a molecularly imprinted polymer (MIP) thin film's coating process, allowing high sensitivity of the resulting microsensor. After description of the Love wave sensor and of the MIP coating process, the functionality of the resulting device is proved with electrical characterization. Deep characterization of the thin film -morphology and print effect -is proposed, based on dynamical responses observed under exposure to different vapors. Results point out a good reproducibility of polymeric films. MIP layers increased responses of sensors to vapors by a factor 3 to 4 compared to bare devices or to devices coated with non-imprinted polymer (NIP). For example, exposure to 4000mg/m 3 (2126ppm) of ethanol in nitrogen induced a frequency shift of -1.4/-0.4kHz with MIP/NIP-coated sensor, respectively

Love wave gas sensor based on DWNTs sensitive material

International audienceThis work focuses on the application related to the detection of low moisture and environmental pollutants. A novel gas sensor with inkjet printed Double Walled Carbon Nano Tubes (DWNTs) on a Love wave sensor platform was developed for Volatile Organic Compounds (VOCs) and humidity detection application. The experiments were conducted in real-time at ambient conditions. Results demonstrate the adsorption of vapor compounds on DWNTs sensitive material and leads for example to frequency shifts of 1.97 kHz and 2.93 kHz with 120 ppm of ethanol vapor and 6.22 % RH, respectively

Association of a Love wave sensor to thin film molecularly imprinted polymers for nucleosides analogs detection

International audienceThe overall objective of this work is to develop and validate a quantitative, non-invasive therapeutic tool to detect selected urinary modified nucleosides as biomarkers of colorectal cancer chemotherapy and to monitor in fine the efficiency of the chemotherapy. Our methodology takes the advantage of high sensitivity of acoustic biosensor combined with high selectivity and robustness of thin molecularly imprinted polymer (MIP) film. In this paper we present a process based on a thin film of a MIP of adenosine 5'-monophosphate (AMP) coating on the sensor surface which is compatible with the acoustic wave propagation. Detection tests of AMP have been performed in aqueous media. The sensor response was recorded in terms of synchronous frequency and total insertion losses after both steps: extraction from, rebinding by the MIP layer. A frequency decrease of 6.875 Hz was recorded for 25μg/mL AMP concentration