MOX resistive microsensors for low concentration methane detection

A series of MOX sensors, having CuO and CoO sensitive thick films were prepared using an eco-friendly technique (sol-gel). The sensor transducers are based on a custom made thick alumina wafer having Au or Pt interdigital electrodes (IDE) printed onto the alumina surface.

The sensing experiment took place inside a custom made ceramic sensing cell, with quartz walls, Teflon seal caps and a metallic plate with dual role: sample holder and sensor heater, due to a special electric heater insertion to insure corresponding working temperature of the sensor.

Sensor response (sensor electrical resistance variations, measured at the IDE contact pads) was recorded at different methane concentrations, using a RLC bridge having a GPIB interface linked with a computer, running custom made Labview based acquisition software.

The sensing experiment took place under lab conditions (dried target and carrier gas from gas cylinders), in a constant gas flow, with target gas concentrations in the 5-2000 ppm domain (calibrated by a mass-flow controller system or MFC) and a direct current (DC) applied to the IDE as sensor operating voltage.

Acknowledgements:

This research was funded by the Romanian National Authority for Scientific Research on Innovation, grant number PN-III-P2-2.1-PED-2019-2073.