Scientists Levitated A Star-Shaped Water Droplet Using Sound
The droplet got put between a transducer and a reflector. The transducer created sound at different frequencies, and the reflector bounced that sound back. Between the two, they created a pressure gradient that kept the droplet in the air.
“Exciting” the droplet at different resonance frequencies caused it to form an oscillating star shape.
When the pressure field strength was increased past a certain point, the droplet went nuts, losing its common symmetrical shape and eventually disintegrating.>
The research was conducted in 2013. However, the video has been making the rounds again now. Enjoy some fluid dynamics eye candy.
Have a look the video below if you want to see a more extended version of it with scientific explanations in between: