Toxic gas sensor using resonant frequency variation in micro-cantilever

Abstract

Our world is facing some drastic changes in the climatic conditions due to the heating effect caused by various greenhouse gases and is increasing at an uncontrolled rate. The people working underground are generally caught unawares of the hazardous gas emission around the locality. Hence an effective sensing and communicating system is required to effectively monitor and alert the neighborhood to save them. This paper aims in finding out a way to quantitatively measure the hazardous gas molecules. The gravimetric sensor works by absorbing the chemical in a polymer, which alters the overall mass of the sensing element i.e a cantilever, thereby its resonant frequency. Here a micro-cantilever beam is fabricated using selective coatings on the surface to selectively absorb the hazardous gases. As the gases are absorbed the mass increases and hence resonant frequency changes. This change in frequency gives the measure of the quantity of gas present in that environment. The major expected advantage of this technique would be the portability, sensitivity, repeatability and economic cost of the sensor that is used.