A novel inkjet printed carbon nanotube-based chipless RFID sensor for gas detection

This paper presents a fully inkjet printed wireless chipless sensor for carbon dioxide detection. It is composed of two split ring resonators 90 degrees rotated to each other for a total size of 18×46 mm². The first resonator is used for gas detection whereas the second provides identification of sensor, and a reference for accurate detection. The conductive part of the sensor is realized with silver ink, and the sensitive part is composed of carbon nanotube-based ink. The detection principle relies on a dual-polarization frequency-stepped continuous wave radar operating in the ISM band from 2.4 GHz to 2.5 GHz. Simulations and measurements both wireless, and with a transmission line, they validate the concept.