MEMS Electrostatic Actuators

 

Diagram of electrostatic actuation. (1) Every third electrode is driven high and these charges get mirrored in the dielectric. (2) A different set of electrodes get driven high. (3) Before the charge in the dielectric can relax, the material is pulled to the next set of electrodes. This sequence is repeated ad infinitum to move the dielectric in either direction.

 

Normally, three phase motors need to have two layers of metal in order to do the routing, but it's possible to do it in only one layer if you use a serpentine second electrode that changes from thick to thin in order to break symmetry. This makes the fabrication of the motor much simpler.

 

Image of an actual printed motor, with probe marks from where it was being tested.

 

Movie of Actuation