P. Coquet

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.

Capacitive microwave resonator printed on a paper substrate for CNT based gas sensor

Inkjet-printed RF electronics fabricated on paper and other flexible substrates are introduced as a low-cost solution for the sensor applications. Inkjet printing is an additive process that has enabled various disruptive technologies combining new materials with novel multidisciplinary operation concepts. This paper presents a fully inkjet printed capacitive structure used to provide a differential detection, by comparing the frequency responses of quasi-twin structures, one with and one without sensitive material. The sensitive surface is printed with a polymer solution containing multi-wall carbon nanotubes (CNTs), and the resonator is dimensioned for operating in the RF band.

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).