Enhancing CO2 sensitivity of a polymer-based RF sensor through functionalization

In this study, we present a dual Radio Frequency sensor coupled with a polymer sensitive material for Carbon dioxide gas detection. A commercially available polymer underwent functionalization to produce a derivative polymer with enhanced properties. The sensing performances of both polymers, when integrated with the RF transducer, were evaluated. The results demonstrate that functionalization led to an increased sensitivity to CO2 while simultaneously reducing sensitivities to relative humidity (%RH) and temperature. The functionalized material exhibited good reversibility and repeatability, displaying a sensitivity of 17.3 MHz/ppm to CO2 at 0% RH, in comparison to the commercial polymer with a sensitivity of 1.35 MHz/ppm. Nevertheless, it is important to note that the sensor's CO2 sensitivity is compromised when exposed to %RH levels exceeding 0. Moreover, the sensor demonstrated a high specificity during tests involving alternative gaseous compounds such as CO, NO2, and O-3.