Coplanar waveguide sensor for Dimethyl Methylphosphonate gas detection at microwave frequencies

Abstract

This study proposes the development of a Palladium-based Coplanar Waveguide (CPW) microwave sensor for the detection of Dimethyl Methylphosphonate (DMMP) gas, considering its importance in warfare security contexts. DMMP is a chemical compound commonly used in the production of nerve agents, making it a critical target for detection in military environments. The sensor was fabricated using the spin coating and lift-off method, ensuring a uniform deposition of a thin palladium layer onto a planar substrate. The interaction between palladium and DMMP leads to changes in the dielectric properties of the sensor, which can be detected using microwave techniques. These variations were processed and analyzed to identify the presence of DMMP in the environment. The sensor underwent experimental testing in a controlled environment, where S21 values were measured. Specifically, DMMP was evaluated at a concentration of 400 parts per million (ppm). It was observed that the presence of DMMP caused changes in the attenuation of the S21 parameter, demonstrating the sensor's sensitivity to the target gas.