Does the actual soundwave itself have an effect on these parts? They mentioned something about a thin layer of lubricant. Wouldn't soundwaves also mess with this layer as well?
It shouldn't; fluid is an insulator and the lubricant has enough (viscosity? tensile strength? I'm not a materials guy) to adhere to the part in question. The soundwaves must be super high-frequency so they should just get absorbed without displacement.
I'd be curious to see if something like this could succesfully handle an Etch-a-Sketch or Magna-Doodle without ruining the picture though.
