Authors: R.L. Townsend, S.A. Rocks, R.A. Dorey, S. Tearle
Affilation: University of Surrey, United Kingdom
Pages: 57 - 60
Keywords: microsensor, particulates, airborne, impedance
Particulate matter is ubiquitous in the environment however industrial processes increase the amount released in the air. Here we show the initial development of a novel sensor capable of detecting airborne particulate matter in real time. Interdigitated microelectrodes (IDEs; gap width 400µm and finger width 400µm) were printed on a silicon wafer substrate and exposed in a wind tunnel for 2, 5, and 10 minutes to Arizona Road Dust with an air sample mass loading of 9.07mg/m3 at a velocity of 1.7m/s. Impedance measurements were taken during exposure every 30 seconds. Blank samples were analysed using SEM and showed an increase in number density over the 2, 5, and 10 minutes. The average loading efficiency was calculated to be 0.17%. Impedance measurements were recorded from the IDE samples showing that the impedance decreased in real time over the 10 minute exposure. The low capturing coefficient was possibly due to surface-particle interaction phenomena, such as particle bounce, impaction and re-entrainment. IDEs have previously been used to detect nanoparticles within an aqueous environment however this is the first report of such electrodes being used to successfully detect airborne particles.