Gas sensors: Alarms for Air Pollution
Air is one of the vital elements for life substance on earth. However it is getting polluted by the release of gaseous waste from industrial power plants and automobiles.
Carbon dioxide (CO2), carbon monoxide (CO) etc are some of the gases responsible for air pollution. According to the WHO report-2014, air pollution caused death of 7 million
people worldwide in 2012. Hence development of highly sensitive, stable and selective gas sensors which can help in determining the air-quality of the concerned region and
act as alarms for air pollution is very crucial.
Gas sensors are devices that respond to the presence of a particular gases and transmit electrical signals which are measured to determine the concentration of the gases
present in the environment. A gas sensor system basically consists of three components: the analyte (target gas), the sensing layer (receptor) which responds to a specific
gas and third component is known as transducer which converts the interaction of the targeted gas at the sensing layer into a measurable signal which may be electrical,
optical or acoustic in nature.
A great deal of research is being encouraged in applying 1-D nanostructures like nanowires and nanorods as sensing layers to achieve high sensitivity and selectivity for
gas sensors. Also, sensing materials like conductive polymers are used as thin film in nanostructure form. Extensive research has been done on using highly sensitive Carbon
nanotubes (CNTs), graphene and silicon nanowires for sensing presence of hazardous gases. However they are very expensive for set up at an industry scale.
So, in the conclusion, it would be right to mention that the field of gas sensors is undoubtedly a recent, highly open, interdisciplinary and relevant area for research having
a large amount of scope as we still need to develop sensors that can respond to gases present even at very small concentration, sensors that can sense a specific gas and show
reliable performance over a long period of time.
Vimal Kumar Singh Yadav
Research: FET Based Gas Sensors (VLSI Lab)