Novel Gas Sensor Signal Acquisition Method: Amplifying Sensor Signals and Enabling Efficient Gas Identification

Enhancing sensor sensitivity and gas identification capabilities is essential for the broad application of gas sensors. Developing efficient transducing methods for sensors can be applied to a wide range of sensors. However, developing such methods for resistive sensors remains challenging. In this study, an operating method that enhances both sensitivity and gas identification capability in resistive gas sensors is presented. The sensor operation is divided into two phases: the reaction phase and the signal detection phase, and propose optimized operating methods for each. In the reaction phase, the chemisorption of oxidizing and reducing gases are maximized through appropriate operating methods for each. In the signal detection phase, a read-bias technique is introduced, enhancing sensitivity across all gases, with a 23-fold increase for 500 ppb NO₂ and a sixfold increase for 50 ppm H₂S. Additionally, the limit of detection (LOD) can be improved, with the NO₂ LOD reduced from 11.8 to 1.4 ppb. Furthermore, a method for obtaining gas-specific signal patterns is presented that reflect the unique diffusion properties of each gas by simply adjusting the signal readout conditions. This approach demonstrates the accurate identification of four different gases using only a single sensor.