Planar Low-Cost RF Sensor for Volatile Organic Compound Detection

In this manuscript, a Polydimethylsiloxane (PDMS)-coated microwave ring resonator (MRR) operating at a resonant frequency of 3.05 GHz was investigated to detect acetone vapor, a common Volatile Organic Compound (VOC), within a closed chamber at ambient temperature. Integrating a solid PDMS layer with an MRR provides an effective platform for vapor detection by leveraging absorption-induced changes in the PDMS layer's dielectric properties. These changes shift the resonant frequency, which, in this case, occurs at 260 MHz in the presence of acetone vapor. The measured results indicate that the proof-of-concept sensor has strong potential for detecting VOCs in air at ambient temperature and for being incorporated into future 6G integrated sensing and communication systems.