ELECTROSTATICALLY CONTROLLED MULTIPURPOSE TORSIONAL STRUCTURES OBTAINED ON MONOCRYSTALLINE SILICON

Torsional structures have been obtained from Si wafers using the four- electrode electrochemical etch-stop and silicon-glass bonding techniqu es. The fabrication process is very simple and is totally compatible w ith CMOS. Finite-element modelling has been used to determine the damp ing factor of the structures. The goal is to reduce the air damping an d enhance the dynamic behaviour by making holes in the plate. The desi gned structures are well suited to implement different micromechanical devices as micromirrors and accelerometers.