Model-based resolution enhancement of a miniaturized ion mobility spectrometer

A numerical model has been used to study the effect of various design parameters on the resolution of our miniaturized ion mobility spectrometer (IMS). This multiphysics model is based on a finite element approach and gives a detailed insight into the convection and migration of gaseous ions in the spectrometer. It can be also applied to other aspiration condenser type IMS. As reported earlier, physical ion-ion and ion-molecule interactions are considered to achieve an adequate accuracy of the simulations. With good conformity between simulations and measurements, both resolution and simplicity of our design could be significantly improved. The optimized IMS can be used in cost and size-limited applications where chemical substances have to be identified at low ppb-level concentrations within seconds.