Collection of liquid phase particles by microfabricated electrostatic precipitator

A microfabricated electrostatic precipitator successfully demonstrated its airborne liquid phase particles precipitation functionality. The particles used in the experiments were polydispersed liquid phase oleic acid particles with sizes ranging from 30 nm to 300 nm. Two configurations with electrode gaps of 1.8 mm and 2.0 mm were tested at 2.2 kV and 2.6 kV, respectively. During the test, the microfabricated electrostatic precipitator was inserted into a flow chamber with an aerosol stream containing oleic acid particles. Particle precipitation is demonstrated via both visual observation and the measurement of the corona current during aerosol exposure. The corona current for the 2.0 mm electrode gap configuration was decreased by approximately 50% and the circuit resistivity is increased by the corresponding magnitude as the oleic acid particles precipitated during a 60 s exposure. The recovery of corona current is observed when the aerosol source is turned off. Wicking of precipitated oleic acid away from the collection grid to its anchoring feature is observed. The analytical and experimental corona current versus time elapsed during the aerosol exposure are calculated and compared. The discrepancy between the analytical and experimental corona currents is consistent with the observed wicking effect and variation in percent coverage on the collector grid by precipitating particles.