Carbon‐nanotube‐loaded planar gas and humidity sensor

Abstract

AbstractThis paper reports a gas and humidity sensor design with improved sensitivity. The design is based on a planar antenna loaded with carbon nanotubes (CNTs). Sensing is achieved by the conductivity change of the CNT film when exposed to various gases or humidity levels. The sensitivity improvement was achieved by replacing a portion of the patch conductor at the dominant edge with a strip of CNT film, and accordingly having the CNT film exercise the maximum effect on the antenna's radiation. The fabricated sensor was tested in a sealed chamber by filling the chamber with several different gases and then with water vapor. The experimental results were excellent, and the gas sensing capability of the CNT‐loaded patch antenna was better than previously reported designs. The sensor was designed for 2.4 GHz so that it can easily be compatible with Wi‐Fi and Bluetooth devices, and the sensor geometry can be easily scaled to other frequencies, which shows great promise for applications of the proposed wireless sensor in environmental monitoring and weather forecasting.