a Microfabricated Gyroscope

The commercial importance of microfabricated sensors is increasing rapidly. However, tools for design and characterization of microelectromechanical systems (MEMS) re-main primitive in comparison to those for their electronic counterparts. In response, we have developed a method to characterize the motions of MEMS. Our method, called computer microvision, combines video microscopy and computer vision to es-timate 3-D motions with nanometer precision. To test computer microvision, a mi-crofabricated gyroscope from the Charles Stark Draper Laboratory was studied. The gyroscope is an angular rate sensor whose area is less than 1 square mm. It consists of two masses driven to vibrate at a high frequency (20 kHz) in the plane of the struc-ture. Rotations of the gyroscope induce out-of-plane motions of the masses which are proportional to the angular velocity of the gyroscope. The structure of the gyroscope make it a difficult target of study. The masses have periodically spaced holes through which the substrate is visible. To unambigu-ously meaure motions of the masses, small regions between adjacent perforations wer