Ultrasonic Levitator

Please note that the base in the pictures is an early version and it has been redrawn.

The levitator works by creating nodes in the air with a 40 kilohertz standing wave.
We know that a sound wave is a moving wave of pressure/ compression and the opposite rarefaction.
This device has two transmitters (other devices use a transmitter and a reflective surface) set at the exact distance apart so that the waves are summed. The nodes are created at the minimum or null point of the wave, it appears it is possible to float or levitate small pieces of polystyrene within the nodes.

My version of the ultrasonic levitator was based on this fun project https://makezine.com/projects/micro-ultrasonic-levitator/ and I’m indebted to the author for this work.

One thing that struck me most was that this could have been made 40 years ago at least, ok without the micro controller but with a simple circuit to generate a 40kHz square wave.

I have designed this simple circuit/ 3D printed frame