Investigation on electrical power efficiency of ultrasonic atomizer

Ultrasonic atomization has emerged as a promising method for generating fine mist from water and other liquids. However, conventional piezoelectric atomizers operating in the megahertz frequency range often exhibit low power efficiency, thereby limiting their applicability in industrial fields where a very large amount of mist is required. In this study, we experimentally examined the relationship between the surface vibration velocity of transducer and atomization rate using a 1.6-MHz piezoelectric transducer, and identified a threshold velocity of approximately 0.7–0.9 m/s for stable atomization. To enhance the efficiency, a stepped horn structure, which is commonly employed in low-frequency ultrasonic systems, was adapted for high-frequency operation. A stainless-steel plate was bonded to the piezoelectric disk element, and quarter-wavelength grooves were introduced to create an array of pseudo-horn structures. Finite element simulations demonstrated that the proposed configuration can significantly amplify the surface vibration amplitude with reduced vibration stress in the piezoelectric element, potentially reducing the required input power for atomization. These findings offer a new pathway for the development of energy-efficient ultrasonic atomizers suited to giant mass production of fine mist for industrial applications.