Effect of Non-Wettability of Piezoelectric Atomizer Hole Wall on Particle Size Reduction

In this study, we analyzed and experimentally verified the effect of the non-wettability of the inner wall of the tapered hole in a piezoelectric dynamic cone hole atomizer on the atomized droplet size. First, we used capillary model to analyze and explain the forces and pressure on the droplet within the hole, examining the impact of the non-wetting property of the wall on the liquid. Then, by using a contact angle tester, we measured the contact angles of water and diiodomethane on metal sheet coated with non-wetting material. Additionally, we coated these materials on the large end of the metal sheet in the atomizer and applied vibrations to the atomizer, causing the materials to pass through the tapered hole and form a thin layer on the inner wall. Finally, we conducted atomized droplet size measurement experiments. The results show that for atomizer working at the same voltage and frequency, the non-wettability of the inner wall of the tapered hole reduces the particle size of the atomized droplets from 7.736μm to 1.246μm.