3 ms·

Xiaomi Mi Mix (2016) used a Piezoelectric Speaker through the screen for audio calling

• gtirloni 3y ago
  From what I'm able to find, it was through vibrating the metal frame, not the screen, and it was removed in later revisions.
  • kurthr 3y ago
    It was the screen, but the piezo strain was applied at the mounting to the frame. They really aren't separate. I believe I worked on this design (though not directly on the piezo) and it was a pain. The easiest way to have a nice solid phone that doesn't rattle or come apart is to laminate it together. You can't do that, if the front surface needs to move relative to the back. You need a large area (~10cm diameter) moving a reasonable distance (~100s um) to make a speaker work at acceptable volumes in the kHz frequency range.