Vibration Control With MEMS Electrostatic Drives: A Self-Sensing Approach

Nanopositioning is the actuation and sensing of motion on the nanometer scale and recent nanopositioner designs have been utilizing microelectromechanical systems (MEMS). This brief demonstrates a simple method to implement vibration control on a MEMS nanopositioner. The actuation and sensing of the system are performed with a MEMS electrostatic drive. The electrostatic drive is arranged to be self-sensing, that is, the drive´s voltage is used to actuate the system and the drive´s current is used to observe the system. With this arrangement, the current is proportional to velocity at the resonance frequency and velocity feedback is used to damp the nanopositioner. To filter the current signal and recover a displacement signal, a charge measurement may be preferred to a current measurement. The self-sensing arrangement was modified to be a charge sensor and resonant control was applied to damp the nanopositioner. With this arrangement, the gain at the resonance frequency was attenuated by 18.45 dB.