Achieving Motion in a Plane Orthogonal to the Substrate

Introduction Recent developments in silicon-based fabrication technology such as fusion bonding, deep reactive ion etching (DRIE) [1] and polyamide joints [2] are expected to enable batch fabrication of mechanically robust micromechanisms that are capable of true 3-D motion. Several MEMS structures and mechanisms have been made for motion in a plane parallel to the surface as in the case of accelerometers (ADXL50) or for out of plane motion as in the case of beam steering using mirrors. However, 3-D motion has not been achieved in the complete sense as not much work has been done in the area of rotary/linear motion in a plane orthogonal to the substrate. In this paper a mechanism for generating rotary motion in a plane perpendicular to the substrate is proposed. This concept can be used to achieve both rotary and linear motion in the orthogonal plane. The key issue for achieving motion in an orthogonal plane lies in the coupling between the mechanisms on the substrate to the mechanisms in the orthogonal plane. A mechanical coupling similar to the bevel gear system is used for transmitting motion/power to the mechanisms in the orthogonal plane.