Pre-shaping command functions to control the dynamic impacts in MEMS

The control of electrostatically actuated microsystems with open-loop strategies has the potential to reduce the switching time with immediate benefits on device performances and, on the other hand, to reduce the impact velocity between electrodes with benefits on the device lifetime and reliability. By applying to MEMS the controlled methods already validated on machines, it was demonstrated that the accuracy of the control is scalable with the dimensions. Residual vibrations of microstructures in the nanometer range are almost completely suppressed: they are reduced to 6% of the uncontrolled vibration amplitude. The reasons of implementing this kind of control are related to reliability enhancement, by reducing the impact velocity, and to the improvement of device dynamic performances. The robustness of the control method against errors in dynamic parameters evaluation was also demonstrated.