3D Coupled Electro-mechanical Simulations InMicrostructures

A finite element approach has been developed to solve the problem of structural displacements due to forces from electrostatic attraction. The method can be applied to typical MEMS structures and has been specially thought to determine the pull-in voltage for that subset of systems in which the structure can be taken into collapse. The FE package ANSYS and subroutines programmed in its own language have been the only tools used for this purpose. So, no interface between different program packages is required. Another trait is the three dimensional capability, which allows studies to be performed without geometrical restrictions on complex structures and includes boundary effects of fields. The different parts of the procedure and some alternatives are discussed, mainly the problem of remeshing the deformed structure. As an example, it has been used to determine the attraction cycle of a line-addressable torsional micromirror.