Modern electronic gas sensors: an overview of the basic physical principles of operation and prospective developments
Electronic gas sensors make it possible to determine the presence of specific chemicals in the composition of a gas mixture and are used to solve various tasks from monitoring atmospheric air pollution to searching for residual traces of prohibited substances. In this paper, not only the basic physical principles of the functioning of gas sensors are considered, but also examples of some prospective developments are given. One of the most frequently used effects in the development of gas sensors is the change in the resistance of a number of semiconductors observed during the adsorption of gas by a substance at elevated temperatures. An important task in this case is the development of microheater designs with increased productivity and reduced energy consumption. Another type of gas sensors are chemically sensitive field-effect transistors used both for searching for certain gases in an air mixture and for analyzing liquid media. In recent years, the development of this type of sensors designed to detect some organic substances and even viruses has been underway. Electrochemical gas sensors can be characterized as one of the most versatile in terms of applications and detectable substances. An important task in the development of electrochemical gas sensors is the choice of the type of electrolyte used. Thermal gas sensors are used much less frequently than metal oxide and electrochemical sensors, but they are still quite useful in a number of applications. Optical gas sensors are implemented on the effects of changing the parameters of optical radiation when it passes through the object under study or when it is reflected from its surface. An approach has also been developed to determine the content of gases, in particular oxygen, based on the effect of luminescence, the effective quencher of which is this gas. Flexible gas sensors have become increasingly effective in recent years due to a number of advantages, such as miniaturization and portability, as well as wearability.
Authors: D. K. Kostrin
Direction: Physics
Keywords: gas sensor, air mixture, concentration, content, detection, sensitivity, selectivity
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