CNT-based EMBG resonator for CO 2 gas detection

In this paper, we present the experimental results obtained in the microwave frequency range for a new CO2 gas detection device that uses an electromagnetic band gap (EMBG) resonator covered with carbon nanotubes (CNTs). The single-wall CNTs (SWCNTs) layer was deposited over the EMBG resonator in the central area, where two coupled lines are placed. The microwave S-parameter measurements of the CNT-based EMBG resonator in air (no gas) and kept inside of a chamber filled with CO 2 demonstrate a shift in the resonance frequency of about 135 MHz and a phase shift of about 26.33 degrees for a 0.72% CO 2 concentration. A very good sensitivity of about 29.72% was obtained for 0.72% CO 2 concentration.