Micro droplet generation using micropore plates oscillated by ultrasonic torsional transducers

Abstract

Monodisperse droplets have been an important subject in fields such as electronic materials, cosmetics productions and medical science. The goal of this study is to generate micro and uniform droplets in various viscosity liquids by using a micropore plate oscillated by an ultrasonic torsional transducer. When the micropore plate was not oscillated, droplets were generated irregularly. On the other hand, when the micropore plate was oscillated by the ultrasonic torsional transducer, droplets were generated regularly by ruffling liquid surface. We have generated droplets in the air by using pure water and silicone oil of various viscosities and evaluated droplets. We have designed the ultrasonic torsional transducer and a droplet generation device to apply a high pressure for the use of higher viscosity liquids. We have succeeded in generating droplets by using pure water when we used the ultrasonic torsional transducer. The average diameter of droplets was 30.0µm and the standard deviation was 0.98. We have also succeeded in generating 50cSt silicone oil droplets using the droplet generation device. The average diameter of droplets was 98.0µm and the standard deviation was 0.76.