Nanoporous Silicon Microcavity Based Fuel Adulteration Sensor

Fuel adulteration is a very common practice in several countries around the world. This paper reports the use of porous silicon as a sensor for the detection of adulteration of petrol and diesel by kerosene. Porous silicon has some very useful properties such as high sensitivity, small size, high surface-to-volume ratio, bio-compatibility and compatibility with silicon IC technology which make it suitable for sensing purposes. The main objective of this work is to develop an optical sensor to detect the level of adulteration in a fuel sample using a porous silicon microcavity (PSMC). Reflectance measurements are used to detect the concentration of kerosene, which is the most commonly used adulterant for petrol and diesel, in the fuel sample. The core principle on which the sensing is based is that a change in the effective refractive index of the microstructure due to the introduction of the fuel in the pores leads to a change in the reflectance spectrum of the structure. The same sensor is used for the detection of adulteration in petrol as well as in diesel. The sensing process is reversible, thus making the sensor reusable.