High-Frequency Ultrasonic Atomization With Pulsed Excitation

Abstract

Ultrasonic atomization is a very convenient method to produce sprays of very small droplets. Resulting droplet size distributions are very narrow and the mean diameter is essentially only controlled by the excitation frequency. Generation of droplets in the micron range requires MHz waves, with voltages around 30 V, which translates into power requirements on the order of 10 W. Tunable wave generators with these characteristics are somewhat uncommon. To explore the capabilities of ultrasonic atomization for inhalation therapies, an excitation source, described in this paper, has been designed. The characteristics of the sprays obtained when driving with it a piezoceramic disk are analyzed.