In order to conduct study, I need to produce controlled vibrations with amplitude (maximum) approx 200 um (micro) at frequency between (100-150) Hz. Vibration amplitude must be controlled with input voltage (Battery operable) while frequency remain constant.
I tried many things :
1) Eccentric Motor - frequency and amplitude, both varied with voltage.
2) Solenoid - difficult to control with voltage. (If any way exists, please suggest me).
3) Voice Coil Motor - Its very costly, I need solution around 10-20 $ max. as project constraint.
4) Linear Resonant Actuator - It is the best solution, but I am not able to find any LRA which can produce vibrations in um (micro metre).
Please suggest me any product exists or ways to produce controlled vibrations.