New approaches for improving selectivity and sensitivity of resistive gas sensors: a review

Purpose - This paper aims to present the methods of improving selectivity and sensitivity of resistance gas sensors. Design/methodology/approach - This paper compares various methods of improving gas sensing by temperature modulation, UV irradiation or fluctuation-enhanced sensing. The authors analyze low-frequency resistance fluctuations in commercial Taguchi gas sensors and the recently developed tungsten trioxide (WO3) gas-sensing layers, exhibiting a photo-catalytic effect. Findings - The efficiency of using low-frequency fluctuations to improve gas detection selectivity and sensitivity was confirmed by numerous experimental studies in commercial and prototype gas sensors. Research limitations/implications - A more advanced measurement setup is required to record noise data but it will reduce the number of gas sensors necessary for identifying the investigated gas mixtures. Practical implications - Fluctuation-enhanced sensing can reduce the energy consumption of gas detection systems and assures better detection results. Originality/value - A thorough comparison of various gas sensing methods in resistance gas sensors is presented and supported by exemplary practical applications.