Carl Bugeja Turns a Piezo Buzzer Into a Sensor and Haptic Actuator

Piezo buzzers are the ubiquitous sound generators in most projects. Did you know they could do more? As Carl Bugeja shows, it is possible to use piezo buzzers as a haptic actuator. The result of his small hack is that you get three devices for the price of one: piezo buzzer, sensor, and haptic actuator.

Using a driver board for another actuator, Bugeja found the board could drive a piezo buzzer, making a buzzer operate like a haptic actuator. The DRV8662-based board, however, outputs 200 volts peak-to-peak. Keep in mind that most buzzers cannot operate at this voltage level for an extended time. But for experimentation, this driver — with a few modifications — works well with buzzers.

Bugeja's experiments continued with three test jigs. The idea was to increase the buzzer's effectiveness by compressing the piezo element inside a housing. The jig for a PowerHap piezo used 3D-printed pieces. Circular piezos, 15mm and 65mm, used milled PCB pieces for their "enclosures."

Limited by the waveform type generated on the DVR8662's evaluation board, Bugeja used an Arduino Uno to generate a waveform and the DVR8662 to drive it the higher voltage needed to create the haptic effect.

Some people might say this solution is an over-complicated method to replace a simple tactile dome switch. (And Bugeja is one of those people!) We see it as an exciting technology to play with, and it could be useful in a situation where a small thin piezo buzzer is already in use.

For more information, check out the full video embedded above. Head over to Bugeja's project page for the PCB files and Arduino code.