Ionic Current Extraction in an Electrostatic-Fluid-Based Tripolar System for Ethanol Sensing

We report a microfluidics-based tripolar system to extract the ionic current the gas discharge process for gas sensing, which is structurally and fluidically compatible with the gas chromatography (GC) systems. The tripolar system was fabricated based on the microelectromechanical systems technology and tested as a gas detector with the assistance of a GC column under different external factors, that is, the applied voltages and the gas flow rates. An analytical model is proposed to address the ion extraction behavior under the coupling effect of the electric field and flow field. The extracted ionic current is demonstrated to have a higher signal quality than the corresponding discharge current for ethanol sensing, regarding the signal-to-noise ratio and selectivity. Moreover, the variation behavior of the ionic current corroborates the description of the physical model. The miniaturized tripolar system constitutes an effective approach to ion extraction for gas sensing under the working voltage down to 40 V, which can be applied as a gas detector in a portable GC system.

Automated summary

A microfluidics-based tripolar system was developed for extracting ionic current in the gas sensing process, compatible with gas chromatography (GC) systems. The system, fabricated with microelectromechanical systems technology, showed higher signal quality than discharge current for ethanol sensing. An analytical model was proposed to explain the ion extraction behavior.