Concept of a miniaturized ion mobility spectrometer and a numerical model for fast system design and optimization

Ion mobility spectrometry (IMS) is a widely used method for detecting low ppb-level concentrations of hazardous compounds, such as chemical warfare agents, explosives and pollutants in air. Simple instrumentation combined with high sensitivity and high selectivity are major advantages of this technique. This paper presents both a novel concept of a miniaturized IMS that is capable of identifying hazardous compounds in air at low ppb-levels and a numerical model based on finite element analysis for fast system design. The model described here considers for the fist time all significant physical effects on the ion transport in an IMS, such as diffusion, coulomb repulsion, electric fields and gas flows. The simulations perfectly match the observations made with our experimental setup. This allowed rapid system optimization towards the highest performance possible under the given physical and economic constraints.