A novel wireless gas sensor based on LTCC technology

This work presents the development of a highly selective wireless NO 2 gas sensor based on a resonant antenna circuit using a low temperature co-fired ceramic (LTCC) technique. The wireless LTCC based gas sensor consists of a planar inductor-interdigital capacitor (LC) resonant antenna, which incorporates two dimensional (2D) SnS 2 nanoflakes as a model NO 2 gas selective material. The fabrication of the LTCC platform is fully described, a brief description on the characterization of the gas sensitive material is presented and eventually the operation of the system for the sensing of NO 2 gas is investigated. The response of the LTCC template was associated to the changes of its resistance and capacitance due to the alterations in the properties of 2D SnS 2 as a result of physical adsorption of NO 2 gas molecules onto its surface. The wireless gas sensing performance under different operating temperatures and NO 2 gas concentrations are presented. The obtained LC gas sensor is successfully used for the wireless sensing of NO 2 in the background of atmospheric gas at concentrations lower than 0.6 ppm. The developed technology has a great promise for establishing wireless gas sensors for harsh environments.