CArbon and Microwaves-based Ultrasensitive gas Sensors – CAMUS

In the areas of safety, health and environment, the detection of chemical compounds, VOCs and toxic gases, is a major societal concern. The explosion in recent years in the telecommunications market has led to the emergence of concept of sensor network. This new concept of communicating objects meets the growing need to deploy sensors for monitoring and analysing distributed applications. These systems rely on an architecture built around wireless autonomous sensors composed of nanostructured materials that are very effective in terms of sorption of chemical compounds, and of new low cost communication electronic devices printed on flexible substrates. Thus, the research effort requires a multidisciplinary approach around the engineering of new materials, transduction mechanisms and electromagnetic waves (microwaves). The CAMUS (CArbon & Microwaves-based Ultrasensitive Gas Sensors) project is proposed by a consortium of four labs with complementary skills: IMS Bordeaux UMR 5218, XLIM Limoges UMR 7252, IEMN Lille UMR 8510, CINTRA Singapore UMI 3288 CNRS-NTU-Thales.

In this project, we propose the realization of a platform for microwave transduction associated with nanostructured materials, graphene and carbon nanotubes (CNTs), allowing the extraction of interference properties of conductivity and dielectric permittivity caused by the interaction of these materials with the target species. Thus, our approach aims to demonstrate the feasibility of a passive microwave resonator on a flexible substrate dedicated to the detection of chemical compounds in the vapor state. This positioning very innovative compared to conventional chemical sensing devices (sensors with metal oxides, microcantilevers, acoustic wave devices, field effect transistors, ...) is justified by our desire to develop new methodologies for autonomous and remote real-time analysis. In this perspective, we have chosen to focus our research efforts on the chemical sensor composed of a specific sensitive layer (nanostructured carbon materials), a microwave transduction platform (planar passive resonator) and the electronic interface (electronic feedback, oscillator). The added value of this study is on the development of detection platforms dedicated to high sensitivity in studying the mechanisms of disruption of a planar microwave resonator. A preliminary literature review and the strong laboratory expertise in IMS development of chemical sensors have led us to address the frequency range of [2- 10] GHz as an appropriate solution to meet our goal of chemical detection platform, together with the compactness requirement. Conformable aspects of these structures provide significant advantages for integration (smart clothing, smart label,...). In addition, this microwave transduction platform also offers the advantage of being adaptable to a wide range of materials with different chemical vapors selective targets.

This project consists of three main parts:
1. Design modeling of microwave transducers (passive resonator planar), IMS-XLIM.
2. Manufacturing resonator devices by inkjet printing on flexible substrate and development of sensitive layers: graphene (CVD) and CNTs (inkjet), CINTRA-IEMN.
3. Fabricating a gas test cell and a measurement electronics (oscillator) and evaluation of sensor in a controlled atmosphere, IMS.