I am currently working on a project that prompts me to find/design sources of mechanical oscillations, similar to the ones generated by a motor with an eccentric load used in mobile phones and similar hand-held devices, but of specific dimensions and shape (specifically ring/hollow cylinder shaped), due to the other parts of the setup.
I considered using magnet and coil, employing somewhat of a speaker driver principle, without a membrane, but I started to question if such a setup in these dimensions can yield sufficient power (hollow cylinder about 5-10cm long, 18mm outer/ 13mm inner radius).
I was wondering if piezoelectric stacks of similar shape could be used for generating oscillations of substantial power, like the one used for example in various haptic devices.
Is it possible to generate significant oscillations in the range of 50-300 Hz with piezoelectric stacks that have a nominal frequency of >50 kHz?