This paper presents the ultrasonic atomizer composed of the lead zirconate titanate (PZT) ring actuator and the Ni nozzle plate with numerous minute nozzles. The atomizer operates at its resonant frequency in out-of-plane vibration. De-ionized (DI) water is fed by the open trough to the porous sponge that is in contact with one face of the nozzle plate and it is ejected through nozzles. Micro-droplets are formed at the opposite face of the nozzle plate. The resonance frequencies of the PZT ring are investigated and compared in theoretical analysis, three-dimensional (3-D) finite-element models (FEM) numerical simulation, and experimental measurement. The performance of the atomizer is examined. This ring shape design of ultrasonic atomizer demonstrates advantage of high atomization rate (64.3ml/min) and high atomization efficiency (l,007ml/h/W) at low power consumption (8.244W).
