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.