Experimental and simulation research on the influence of voltage amplitude, frequency and carrier gas flow rate on the performance of FAIMS

Abstract

A micro sensor chip of High-field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) was designed and fabricated by inductively coupled plasma (ICP) etching on the both sides of silicon and double silicon-glass bonding, with dimensions of 18.8 mm×12.4 mm×1.2mm. The sample ions were created at ambient pressure by VUV lamp ion source, which was equipped with a 10.6 eV photo discharge lamp (λ=116.5 nm). The 2-pentanone was adopted to illustrate the influences of high-field rectangular asymmetric waveform voltage amplitude, frequency and carrier gas flow rate on the performance of FAIMS sensor chip. The experiment results showed that with the frequency or carrier gas flow rate increasing, or voltage amplitude decreasing, the FAIMS sensitivity increases, and that the resolution decreases with the increasing of the frequency or flow rate. The FAIMS simulation results based on the SIMION software was in agreement with the experimental results. The FAIMS detection sensitivity experiment showed that the FAIMS sensor chip can detect positive and negative ions simultaneously, and has detection sensitivity as low as 0.1 ppm for acetic acid.