Mini Acoustic Levitator

Ultrasonic sound waves always amaze my with their cool properties. While being inaudible to humans these waves can also make small light things float in air.

Two ultrasonic transmitters facing eachother transmit sound waves of 40KHz. When the two waves overlap they create something known as standing waves. Specific points within these waves remain fixed while others between them vibrate with the maximum amplitude.
If any small object is placed in these fixed points, they themselves stay in that point and looks like it is floating.