Sensing of Hydrocarbon using Frequency Variation in Micro-Cantilever

Our country India is facing some drastic changes in the climatic conditions due to the heating effect caused by various greenhouse gases. The most harmful gas among them is the hydrocarbon family and is increasing at an uncontrolled rate. Hence an effective sensing and communicating system is required. This paper aims in finding out the quantity of the major polluting gas methane. The gravimetric sensor works by absorbing the chemical in a hydrocarbon sponge, 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 Silicon Carbide coatings on the surface to selectively absorb the hydrocarbons. As the gases are absorbed the mass increases and hence there is a change in resonant frequency. 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 repeatability of the sensor that is used.