Evaluation of MOX gas sensor transient response for low-power operation

Metal-Oxide Semiconductor gas sensors are small in size and affordable, which makes them appropriate for implementation in battery-powered wearable sensing devices. However, their big flaw is the need to be heated to a certain temperature to react with the gas from the atmosphere, which consumes energy and drains the battery of the sensing device. In this paper we experimentally evaluate the possibilities to determine changes in gas concentration from the very beginning of the sensor's response. Our experiments in controlled conditions show that the increment of CO concentration could be determined in the first 65 ms of sensor heating, while the sensing layer is still in its transient state. That indicates the possibility of more than 30 times energy savings compared to the experiments where the CO concentration is determined after the sensing layer reaches stable state.