A Micro-fabricated Hexagonal Digital Electromagnetic Actuator

Abstract

This paper presents a micro-fabricated digital electromagnetic actuator able to realize 3D displacements. The actuator consists of a mobile part, placed inside a silicon hexagonal cavity. The mobile part of an actuator can reach up to twelve discrete positions distributed between two different levels along z-axis(six positions at each level). The switching in xy-plane between the six positions is achieved using planar conductors placed beneath the cavity whereas, switching between the levels along z-axis is obtained with the help of an electromagnetic air-core coil. The cavity is surrounded with six cylindrical permanent magnets, in order to obtain magnetic holding. A semi-analytical model has been realized to design the prototype. Deep reactive Ion Etching(DRIE) process has been undertaken in order to obtain a microfabricated prototype. Experiments have been conducted to verify the ability of the actuator to reach twelve positions and to characterize the displacement stroke along x-, y- and z-axis.