Electromechanical and fluidic evaluation of the resonant microfan gas pump and aerosol collector

Abstract

This paper reports on the fluidic and electromechanical performance of the resonant microfan as an in-channel gas pump and suspended airborne particle collector. Experiments with parametric resonant fan arrays were performed in order to observe the dependence of the volumetric flow rate in a test channel with respect to changes fan length, resonant frequency and deflection. Flow rates of approximately 10 μl/min were produced by single fans with the flow increasing by 270% for three fans operated simultaneously in the same channel (the capability exists for many fans to be arrayed in a microchannel system). Because optimum operation of microfan series arrays is strongly related to frequency selectivity and non-uniformities in the fabrication process, the mechanical Q-factor was measured in order to estimate the reduction in deflection amplitude that occurs when fans are driven at frequencies slightly off resonance. The Q-factor of several different fan designs ranged from 10 to 43 in a standard air environment. The ability of the microfan to collect and transport suspended airborne particles was also experimentally studied using circular fan edge profiles and laser illumination of particles.