Room temperature ionic-liquid electrochemical gas sensor array system for real-time mine safety monitoring

This paper presents a real-time, electrochemical gas sensor array system featuring room temperature ionic-liquid interfaces and targeting safety monitoring in underground mines. A prototype system was constructed using a custom ionic-liquid sensor array, a custom multi-mode electrochemical sensor readout board, and a commercial low power microcontroller board. Gas sensors for multiple mine gases were implemented in a 2 by 2 miniaturized array. A novel resource-sharing circuit tailored to our gas sensor array was utilized to significantly decrease power, cost and size while implementing two electrochemical detection modes. The system achieves a resolution as high as 0.01% vol in amperometry mode and 0.06% vol in impedance spectroscopy mode for oxygen as an example target gas.