A new wireless interface for resistive chemical sensors

This paper presents the design, realization, and performance measurements of a wireless interface prototype for chemoresistive sensors. The new design aims at reducing the hardware components of the sensing node in order to have an efficient sensing mechanism in terms of time and power consumption. In our design the signal transmitted by the sensing node is directly proportional to the sensing film resistance. This means that minimum signal conditioning and no data processing at all are needed. With conventional sensing node, the processing time to produce an output signal from the measurement may have a significant impact. With our approach, this time is only needed on the sink node where higher performance processors can be used. The system is tested with a commercial variable resistance gas sensor (MOX) and proved to be suitable for various combinations of CO and NO₂ gas concentrations.