A smart gas sensing microsystem

This article describes a microfluidic system for the compositional characterization of gases. The system consists of a silicon motherboard configured with different flow channels. The flow channels are guided to cavities capable of picking up microstructured thin-film gas sensors. Microvalves may be integrated for the control of the gas stream. The sample flow is generated by a micropump also integrated into the silicon motherboard. The system faces the main problem of thin-film gas sensors-the signal drift of the resistive layer. The idea is to overcome this undesirable effect by cyclic operation of the sensors in respect of purging, calibration and final measurement. The system components are fabricated by silicon microsystem technologies