“Floating things with sound might seem like science fiction or something you could only find in a physics lab, but actually many people have shown that its easy to diy. There are simple designs:
www.instructables.com/id/Easy-Acoustic-Levitator/
www.instructables.com/id/Mini-Acoustic-Levitation/
and there are not quite as simple designs:
www.instructables.com/id/Acoustic-Levitator/
In this project I’m aiming for something in-between along with some cool demonstrations. If you just want a quick overview then check out the post on my website.
The physics behind acoustic levitation gets a little complicated but the general idea is that if you take a sound wave and reflect it back into itself, this will setup a stationary wave. Somewhere along that wave there will be a condition (or several of them) where the forces are directed towards a single point, and if the acoustic power is high enough, this can overcome gravity and we get stable levitation.”