This paper presents a novel particle-trapping mechanism that enhances the filtration efficiency of an electrostatic precipitator (ESP). Collecting electrodes are covered with guidance plates that have patterned holes. Gaps are intentionally left in-between the guidance plates and the collecting electrodes, so that particles can travel through these holes and sit inside the gaps. Guidance-plate-covered ESPs have up to 20% higher filtration efficiencies than traditional ESPs. The parametric studies show that the number of holes in the guidance plates has more influence on filtration efficiency and power consumption than the diameter of the holes. (C) 2014 Elsevier Ltd. All rights reserved.