Miniaturized Integrated Gas Sensor Systems Combining Metal Oxide Gas Sensors and Pre-concentrators☆

An integrated microsystem for (indoor) air quality monitoring applications has been realized. By combining a gas pre-concentrator based on metal-organic framework materials and a metal oxide semiconductor gas sensor in a single SMD package, a device for detecting ppb levels of volatile organic compounds was designed, integrated and tested with benzene as a target gas. The system has been characterized in FEM simulations concerning its gas pre-concentration capabilities and behavior. Test measurements were performed using benzene at concentrations in the ppb range. Both the simulations and the measurements show the suitability of the system design for the task. Significantly increased gas concentrations have been observed during thermal desorption from the pre-concentrator after gas adsorption at a low temperature.