Self-sensing electrostatic drive in a MEMS nanopositioner for the application of vibration control

Nanopositioning is a core field of nanotechnology. Recent nanopositioner designs have been fabricated using microelectromechanical systems (MEMS) technology due to the benefits associated with microfabrication. The electrostatic drive is a MEMS transducer commonly used to actuate these systems. This paper presents an implementation of a self-sensing electrostatic drive. The self-sensing drive operates by controlling the voltage across the terminals to actuate the system, and measuring the current through it for sensing. The response of the system is experimentally verified. Simulations are then used to demonstrate the drive's suitability to control the resonant motion of a MEMS nanopositioner. Damping can be achieved by feeding back the current measurement. However, the capacitive nature of the electrostatic drive amplifies high frequency input signals. An integrator is used to filter these high frequency signals and a resonant controller is then used to control vibrations. With the resonant controller, the quality factor can be reduced from 144 to 7.32.