Simulation‐based design and optimization of rectangular micro‐cantilever‐based aerosols mass sensor

Abstract

Micro‐Cantilever (MCL) is a thin film structure that is applied for aerosol particle mass sensing. Several modifications to the rectangular MCL (length‐to‐width ratio, slots at the anchor, serrations at its side edges) are made to deduce the role and influence of the shape of rectangular MCL-based aerosol mass sensors and reduce gas damping. A finite element fluid‐structure interaction model was used to investigate the performance of MCL. It is found that (I) the mass sensitivity and quality factor decline with the increasing of length‐to‐width ratio which alters the resonant frequency of the MCL. The optimum conditions, including the length‐to‐width ratio (ϬIw = 5) and resonant frequency (f0 = 540.7 kHz) of the MCL, are obtained with the constant surface area (S = 45,000 μm2) in the frequency domain ranging from 0 to 600 kHz. (II) The slots can enhance the read‐out signal and bring a small Q factor drop. (III) The edge serrations on MCL significantly reduce the gas damping. The results provide a reference for the design of aerosol mass sensor, which makes it possible to develop aerosol mass sensor with high frequency, sensitivity, and quality.