Investigation of Ultrasonically Levitated Droplets for Sonochemistry with High-Speed Camera Observations

Ultrasonic levitation is a non-contact method of manipulating samples in mid-air that has drawn significant interest in the fields of biochemistry and pharmaceutical science. In these fields, the stability of levitated droplets is crucial for effective applications. This study aims to investigate the droplet levitation while focusing on their oscillation dynamics and levitation stability using an ultrasonic levitator with multiple nodes. A high-speed camera was used to observe the behavior of the droplets, and the results showed that the number and position of levitating droplets are critical factors affecting the stability of the levitation. By exploring the high-speed camera observations, we seek to understand the dynamic interactions between ultrasonic waves and these levitated droplets, which could induce oscillation and can be used for sonochemistry.