Jean-Luc Lachaud

Chemical gas sensor based on a novel capacitive microwave flexible transducer and composite polymer carbon nanomaterials

This study presents the results on the feasibility of a resonant planar chemical capacitive sensor in the microwave frequency range suitable for gas detection and for wireless communications applications. The objective is to develop a low cost ultra-sensitive sensor that can be integrated into a real time multi-sensing platform. The first demonstrators target the detection of harmful gases such as volatile organic compounds (VOCs) to monitor environmental pollution.

Ink-jet printed flexible gas sensors based on electromagnetic transduction and carbon materials

This paper presents the feasibility of a novel gas sensor based on electromagnetic transduction and Carbon Nanotubes (CNTs) sensitive materials. The sensor is designed to provide a differential detection, by comparing the frequency response with and without the sensitive material, in the frequency band between 1 GHz to 10 GHz and can operate for wireless applications. Two designs are presented: micro-strip stub-based and U-shaped resonators, for conductive and non-conductive CNTs, respectively. The first structure has been fabricated on a flexible Kapton substrate with ink jet printed CNTs. Preliminary electrical characterizations validate the CNTs influence and the innovative measurement test cell based on low cost process.

Love wave-based acoustic components as versatile sensors for electronic nose or tongue. Application to cancer monitoring

Surface Acoustic Wave or SAW-based devices are spreadly studied for highly sensitive and real-time chemical or biochemical sensing applications. In particular, Love waves or shear horizontal waves guided in a thin surface film, are of particular interest for liquid samples. In this work, we present a basic structure and introduce its versatility through a large spectrum of applications investigated in IMS labs. Then we focus on a device dedicated to the detection of nucleosides as cancer biomarkers for the monitoring of therapy. In this case, thin films of Molecularly Imprinted Polymers (MIPs) are used as sensitive matrix for the detection of adenosine-5-monophosphate (5-AMP) and Pseudouridine (pseu) in liquid medium. The acoustic delay-line is associated to a microfluidic chip and inserted in an oscillation loop. The real-time resonance frequency of the MIP-based device to various concentrations of 5-AMP and pseu has been investigated. Detection limit as low as 5 ppm of 5-AMP has been achieved.

Mesoporous titania-coated Love wave sensors and FEM model applied to viscosity micro-measurements

This paper presents the interest of a Love wave sensor coated with a TiO2 mesoporous film as sensitive layer. The main novelty is related to the modelling of the device and simulation by using Finite Element Method with COMSOL Multiphysics software, which is a good way to take into account the physical properties of porous 3D-layers. Experimental devices have shown a good agreement with simulated results. Furthermore, experimental results with several Newtonian liquids, viscosities from 1 to 7 cP, are investigated. The sensitivity with a 300 nm thick porous sensing layer was 30 times that of the bare device, with interesting dynamical issues to be further studied, giving rise to the great potentialities of such architectures for microrheological measurements.

Capacitive microwave sensor for toxic vapor detection in an atmospheric environment

This paper presents an inkjet printing capacitive microwave sensor for toxic vapor detection. The designed sensors were presented and fabricated with success. The experiments show sensitivity to ethanol vapor according to the S parameters. It is equal to 0.9 kHz/ppm and 1.3 kHz/ppm for the sensors based on 5 and 50 sensitive layers respectively. This sensor will be integrated into real-time multi-sensing platforms adaptable for the Internet of Things (IoT).