This Is the Prettiest Acoustic Levitator You’ll See Today
Arvind Singh decided to go all out when he built his acoustic levitator, and it’s the prettiest example that you will see all day.
Acoustic levitation sounds like borderline quack pseudoscience, but it’s actually just a simple demonstration of physics. As sound waves move through a material medium—air included—they create vibrations. If you’ve ever heard a window shake when your rude neighbor cranks up their stereo’s bass, then you’ve experienced that for yourself. It’s entirely possible to harness those vibrations to keep small, light objects floating in midair. In fact, it’s not even an expensive undertaking, and you can build a simple acoustic levitator for less than $30. But Arvind Singh decided to go all out when he built his acoustic levitator, and it’s the prettiest example that you will see today.
Like most acoustic levitators, this uses ultrasonic transducers. The most basic setup for an ultrasonic acoustic levitator has two ultrasonic transducers facing each other along a vertical axis. Because they’re sending sound waves towards each other, there are small pockets that are created in the areas between where those waves intersect. If a small and light enough object is placed in one of those areas, it will be suspended by the sound waves pushing on it from above and below. Singh’s ultrasonic acoustic levitator works in the same way, but uses a total of 72 transducers—36 on top and 36 on bottom.
Singh based this project off of a tutorial on Instructables, but made some improvements. The original tutorial called for the use of an Arduino Nano to control the transducers, but Singh has switched that to a Teensy 3.2 microcontroller development board. That is much more powerful, and allows for smoother control of the waves. A TFT screen shows the current wave frequency, and an Adafruit joystick can be used to slowly adjusting the timing, so levitating objects can be moved up and down. To give it a classy appearance, Singh 3D-printed all of the enclosure parts in wood PLA, sanded them, stained them, and then finished them with some varnish. The result is a beautiful and very functional acoustic levitator.